Health and Caring for a Bouvier
What does this mean for you as a UK Bouvier owner?
As a breed in the UK there are very few recorded health concerns for Bouviers that are bred within the UK. Therefore, most of the current data that is available regarding health concerns comes from the worldwide Bouvier community and most, if not all, of these breeders will test for these health issues. So should a breeder have used a dog from another country it will most likely have been tested for one or more of these health issues.
You must also remember that these are health issues that can occasionally be seen in a Bouvier, there are also health issues for many other breeds including non-pedigree dogs who receive no health testing.
No breeder can guarantee that he/she will never produce a dog that develops a health condition, but with knowledge, good record keeping, diligence and foresight the risk of producing these potentially devastating, and sometimes fatal, diseases can be significantly reduced.
As a numerically small breed within the UK, the Bouvier des Flandres Club of Great Britain believes that all of its members should be active in identifying any ongoing or prevalent problems in our breed. It is hoped that by recording such data and by working with the British Kennel Club, its associates, the Small Animal Veterinary Association, the Animal Health Trust and Bouvier des Flandres Clubs around the world that action can be taken to prevent these becoming commonplace by instigating interest and research into these conditions.
The club has a nominated Breed Health Co-ordinator to collate any information relating to the health of the breed.
The representative for our breed is Andrew Hall and he can be contacted via email at: email@example.com
Bloat and Gastric Torsion
Bloat, Gastropexy, Gastric Torsion, Stomach Torsion, Twisted Stomach, GDV
Gastric Dilatation-Volvulus (GDV) is a rapidly progressive life-threatening condition of dogs. The condition is commonly associated with large meals and causes the stomach to dilate, because of food and gas, and may get to a point where neither may be expelled. As the stomach begins to dilate and expand, the pressure in the stomach begins to increase. The increased pressure and size of the stomach may have several severe consequences, including:
prevention of adequate blood return to the heart from the abdomen loss of blood flow to the lining of the stomach rupture of the stomach wall pressure on the diaphragm preventing the lungs from adequately expanding leading to decreased ability to maintain normal breathing
The entire body suffers from the poor ventilation leading to death of cells in many tissues. Additionally, the stomach can become dilated enough to rotate in the abdomen, a condition called volvulus. The rotation can lead to blockage in the blood supply to the spleen and the stomach. Most pets are in shock due to the effects on their entire body.
The treatment of this condition involves stabilization of your pet, decompression of the stomach, and surgery to return the stomach to the normal position permanently (gastropexy). Abdominal organs will need to be evaluated for damage and treated appropriately as determined at the time of surgery.
Several studies have been published that have evaluated risk factors and causes for gastric dilatation and volvulus in dogs. This syndrome is not completely understood; however, it is known that there is an association in dogs that:
have a deep chest (increased thoracic height to width ratio)
are fed a single large meal once daily
are related to other dogs that have had the condition
It has also been suggested that elevated feeding, dogs that have previously had a spleen removed, large or giant breed dogs, and stress may result in an increased incidence of this condition. A early study also determined that dogs fed dry dog foods that list oils (e.g. sunflower oil, animal fat) among the first four label ingredients predispose a high risk dog to GDV.
Nearly all breeds of dogs have been reported to have had gastric dilatation with or without volvulus,
Signs and Symptoms:
● Initial signs are often associated with abdominal pain. These can include but are not limited to:
● An anxious look or looking at the abdomen
● Standing and stretching
● distending abdomen
● Retching without producing anything
As the disease progresses, your pet may begin to pant, have abdominal distension, or be weak and collapse and be recumbent. On physical examination, pets often have elevated heart and respiratory rates, have poor pulse quality, and have poor capillary refill times. Abdominal distension is also commonly noted.
Stabilization and surgery are best when performed early in the course of the disease; mortality rates increase with the severity of disease. If your pet has exhibited any of the above clinical signs, they should be evaluated by your primary care veterinarian immediately. Surgery is indicated if the diagnosis of gastric dilatation with or without volvulus has been established.
As gastric dilatation worsens and full body effects become prolonged, many secondary complications may occur.
Diminished respiration and cardiac output throughout the course of the disease leads to poor oxygen delivery to many tissues (hypoxia). This leads to cell death in the liver, kidneys, and other vital organs.
Cardiac arrhythmias (abnormal heart beats) are commonly seen because of the hypoxia.
The lining of the entire gastrointestinal tract is at risk of cell death and sloughing.
As the condition progresses, toxins may be increasing locally and when gastric dilatation is relieved these may circulate through the body resulting in additional cardiac arrhythmias, acute renal failure, and liver failure. Bacteria also commonly gain access to the blood during this condition leading to bacteremia (bacteria in the blood) and sepsis.
Figure 1. A lateral radiograph of a dog with a gastric volvulus. Note the stomach is markedly distended with gas (which shows up as black on the radiograph) and the stomach is occupying nearly the entire abdomen.
Most veterinarians will recommend initial bloodwork that includes a complete blood count (CBC), serum chemistry, and a urinalysis. These allow for the determination of the nature of the metabolic disturbances that may be concurrently happening. It also allows your veterinarian to rule out certain diseases which may mimic the clinical signs of gastric dilatation.
Additionally, abdominal x-rays are used to confirm a diagnosis (Figure 1) and an electrocardiogram (ECG) is used to evaluate the presence of cardiac arrhythmias which are commonly seen later in the disease course. Blood gas analysis is also commonly performed to evaluate the nature and severity of the respiratory compromise. Additional tests may be recommended by your veterinary surgeon.
BVA comparison HD schemes 2012
COMPARISON OF VARIOUS ASSESSMENT SCHEMES FOR HIP DYSPLASIA
The BVA does not issue grades and neither does it allocate subjective descriptions of the degree of HD (e.g. ‘mild’, ‘severe’) to specific scores. The BVA Scheme instead creates a score based on individual parameters in each hip, including both those which describe subluxation (i.e. reflecting laxity in the soft tissues) and those which describe secondary, degenerative change (i.e. osteoarthrosis, OA). Two dogs may receive the same score for different reasons: one because of severe subluxation without evidence (at the time of radiography) of OA, and the other because of much milder subluxation but in the presence of OA. Both of these are clear evidence of significant HD, albeit in different manifestations. The BVA’s recommendation to breed only from dogs with scores below the breed median or well below the breed mean takes into account both the fact that the same score can arise from different causes and also that anatomical variations between breeds exist. Other HD schemes link the two processes of underlying laxity and secondary OA and their subjective descriptions do not easily allow categorisation of dogs with predominantly subluxation or predominantly OA. It is therefore impossible to give precise numerical equivalents to the descriptive grades of other schemes which will apply to every case. Should a dog be considered for importation into the UK for breeding the BVA’s advice is for its hip radiograph to be submitted for scoring, to permit meaningful comparison with other dogs of the same breed.
A further complication is the use of highly subjective terminology such as ‘fair’, ‘mild’, ‘moderate’ etc. in other schemes. In English many vets (and doctors) would use an extra term ‘marked’ between categories of ‘moderate’ and ‘severe’ when describing any type of abnormal medical finding. Therefore the BVA scores given in the table reflect the description of the hip given in OFA’s explanatory text, rather than our opinion of the degree of HD present. For example, our scores of 9-18 per hip fit with OFA’s description of ‘mild HD’ whereas we would consider dogs with scores at the higher end of this range to be much more than ‘mildly affected’ by the disease.
a) Final grading is based on the appearance of the worse of the two hips for FCI (Europe), Germany, Switzerland and OFA (USA).
b) UK (BVA) scores are therefore shown for ONE joint only; the higher of a dog’s two individual hip scores should be considered when making comparisons with other schemes, not the dog’s total score.
The table below gives an approximate correlation between different schemes.
|A Normal hip||Excellent||0||A1||0||0|
|C Mild HD||Mild||9-12||C1||7-9||1|
|D Moderate HD||Moderate||19-30||D1||13-15||2|
|E Severe HD||Severe||>30||E1||19-21||3|
What is cataract?
Cataract is an opacity or clouding in the lens in the eye. The opacity normally makes the lens look white. The lens in the eye is like the lens in a camera except that, rather than being at the front as it is in a camera, the lens in the eye is deep inside it, just behind the coloured part of the eye (the iris). The lens shows up as black in the centre part of the eye (the pupil). The lens is normally crystal clear but it looks black because the darkness inside the eye shows through it. The lens is there to focus light on the sensitive tissue at the back of the eye (the retina).
Cataracts often form in both eyes and they frequently get worse. One eye is often more affected than the other, at least initially. It is not known why most cataracts develop. They are most common in older dogs and sometimes they occur due to other problems such as diabetes or disease in the back of the eye (the retina). Some cataracts are inherited.
What treatment is there for cataracts?
At the moment the only treatment for cataracts is surgery. Unfortunately not every cataract is suitable for surgical treatment, and it is necessary for the eye specialist to assess each patient and decide what therapy might be possible.
The previous belief that it is best to let a cataract ‘ripen’ and the eye to become totally blind before removing the opaque lens (the cataract) has been proven wrong. Any cataract that is developing will cause potentially damaging inflammation in the eye due to release of lens proteins – a condition called ‘lens-induced uveitis’. Lens induced uveitis can be subtle and easily missed – or, in some cases, it can be severe and associated with an obviously sore and inflamed eye
Left untreated, even low levels of lens induced uveitis are likely to result in complications, including adhesions (sticking) between the iris and the lens, retinal detachment (where the light-sensitive tissue at the back of the eye comes away from the back of the eye and stops working) and glaucoma (increased pressure in the eye which is potentially blinding and painful). Many eyes with long-standing cataracts that have not been operated on will eventually become irreparably blind and painful, and have to be removed as a result of the effects of lens-induced uveitis.
Early cataract surgery is therefore recommended in order to avoid the detrimental effects of lens-induced uveitis, and in general surgery is carried out once a cataract starts to interfere significantly with vision. This especially applies to young and diabetic patients, where progression of cataracts can often be rapid and result in significant complications if treatment is delayed. Cataracts in older dogs or patients with very slowly progressive cataracts may be monitored, but we will often recommend the prophylactic use of anti-inflammatory drugs in such cases.
ED grading scheme
BVA/Kennel Club elbow dysplasia grading scheme
The elbow dysplasia (ED) grading scheme is based on that of the International Elbow Working Group, IEWG, as follows:
• Grade 0 = a radiographically normal elbow.
• Grade 1 = there is no visible primary lesion but secondary new bone (osteoarthritis) up to 2mm in depth is present at any site around the elbow joint.
• Grade 2 = (a) a primary lesion is visible (eg. medial coronoid disease or ununited anconeal process) without visible osteoarthritis OR (b) no primary lesion is visible but osteoarthritis of more than 2mm and up to 5mm in depth is present at any site around the elbow joint.
• Grade 3 = (a) both a primary lesion and any amount of osteoarthritis are visible OR (b) no primary lesion is visible but osteoarthritis over 5mm in depth is present at any site around the elbow joint.
The overall grade is that of the worse of the two elbows.
It is strongly recommended that breeders wishing to reduce the risk of elbow dysplasia should select their breeding stock (both dogs and bitches) only from animals with an overall grade of 0.
Dogs with elbow grades of 2 or 3 have marked osteoarthritis likely to be due to ED, with or without a visible primary lesion. There is a significant chance of ED being passed on to the offspring.
Dogs with elbow grades of 1 show mild or early osteoarthritis which is also likely to be due to ED. They should only be used for breeding with caution, taking into consideration the ED grades of as many relatives as possible, as well as the results of other health tests and characteristics.
Elbow dysplasia has been identified as a significant problem in many breeds. Importantly, the condition appears to be increasing worldwide. It begins in puppyhood, and can affect the dog for the rest of its life.
Veterinary surgeons have been to some extent. Once the dog reaches aware for many years of a skeletal maturity the primary lesions number of conditions that may stabilise. However, once abnormal begin in puppies and cause development has started with a primary
such disease to be widely recognised and a scheme for its assessment and control is well established in the UK. Elbow dysplasia (ED) is a significant problem in many breeds worldwide, and although it begins in puppyhood it can continue to affect the dog for the rest of its life.
The principal cause of ED lies in the genetic make up of the animal. Therefore, a scheme that screens animals for elbow abnormalities will allow animals with the best elbow joints to be chosen for breeding, and will help to reduce the level of the problem in the canine population.
Elbow dysplasia — the disease
ED simply means ‘abnormal development of the elbow’. The term includes a number of specific abnormalities that affect different sites within the joint. These cause problems by affecting the growth of the cartilage which forms the surface of the joint or the in particular, abnormal wear of the joint surfaces and osteoarthritis (sometimes termed arthrosis, or degenerative joint disease — DJD). The secondary lesions cannot be reversed and remain a potential problem for the rest of the dog’s life.
The elbow is particularly vulnerable to this type of disease. The joint resembles a hinge in which the bones and cartilage forming each side of the joint have complex shapes that fit together closely. The elbow has a wide range of joint movement and normal foreleg gait is more dependent on the elbow than the other joints. Thus, a small change in the shape of one part of the joint can have major consequences for the joint function, like a small piece of grit in a door hinge. Once elbow function is affected, foreleg gait becomes altered.
An additional problem with ED is that lame dogs are only the tip of the ‘disease iceberg’. Many dogs have subclinical lameness. Hip dysplasia was the first lesion, further secondary changes follow,
structures around it. These abnormalities are primary lesions, which then induce a secondary osteoarthritic process. The most common primary lesions are:
● O steochondritis dissecans (OCD or OD)
● F ragmented or ununited medial coronoid process (FCP)
● U nunited anconeal process (UAP)
There are other, rarer, primary lesions that may occur in combination with these or on their own. Primary lesions begin early during the growth of the puppy,
2 and are commonly present in both elbows
The ‘flexed lateral’ view is a side on view of the elbow. This view allows examination of the secondary changes in ED which occur in the shaded areas. Note how some of the shaded areas here are overlaid by other structures, which makes them difficult to examine disease in that they have primary lesions or osteoarthritis in their elbows but do not appear obviously lame. Some dogs will be symmetrically lame in each foreleg, which can be very difficult to see. Fortunately, these subclinical dogs can often be identified by taking radiographs (x-ray films) of their elbows. Even though they appear to show no lameness themselves, they have a high chance of producing lame offspring if they breed.
Causes of elbow dysplasia
ED is a multifactorial disease, which means that a number of factors can influence the occurrence of the condition. The most important factor, however, is the genetic make up of the dog. Other factors such as growth rate, diet and level of exercise may influence the severity of the disease in an individual dog, but they cannot prevent the disease or reduce the potential of the dog to pass on the disease to offspring. However, studies show that ED has a high heritability confirming that a high proportion of the disease is genetic.
As the individuals of each breed of dog have a proportion of their genetic make up (genotype) in common, it is not surprising that some breeds are more vulnerable to a heritable condition than others. In general, medium and large breed dogs are considered to be most vulnerable to ED, although the condition has been found in some smaller breeds.
Unfortunately, ED is not controlled by a single gene or a simple inheritance. It is a polygenic characteristic, which means that it is controlled by the combination of many genes. One way of visualising this is to think of a ‘normal’ dog as carrying a few of the genes that can cause elbow problems. A dog with subclinical disease will have more of these problem genes, and a lame animal will have a higher proportion still.
Control of elbow dysplasia
As the genotype is the overwhelming influence in the cause of ED, the disease can be controlled by minimising the problem genes within the population. This means selecting sires and dams with the best genotype. As yet there is no laboratory test on blood or other tissue samples to enable us to select the best genotype. However, dogs can be screened reasonably effectively by radiographing (x-raying) the elbows and looking for the signs of ED.
If sires and dams are only selected from animals with no or minimal ED, most of the clinical and subclinical animals can be eliminated from the breeding programme, and so prevent them passing on their defective genetic make up to the next generation. The success of such screening depends on a high proportion of the breed participating and making the information public so that low-risk animals can be selected for breeding. There is an international standard for screening schemes administered by the International Elbow Working Group (IEWG), which encourages a coordinated approach to the problem through regular meetings.
The UK elbow dysplasia scheme
The Canine Health Schemes (CHS) is an association between the British Veterinary Association (BVA) and the Kennel Club
(KC) to run a screening scheme along IEWG guidelines. Initially, schemes were run by individual breed groups such as the Bernese Mountain Dog Club of Great Britain and the Guide Dogs for the Blind Association, which were successful in reducing the incidence of ED.
The grading procedure
Although a number of different views have been suggested, two radiographic views of each elbow joint are now taken as described on page 4.
The owner is liable for their veterinary surgeon’s fee for anaesthetising the dog and taking the radiographs, as well as the CHS’ fee for the grading. The cost is currently reduced if hip dysplasia and elbow dysplasia films are submitted for screening at the same time. The ‘extended lateral’ view permits visualisation of some of the shaded areas obscured by the ‘flexed lateral’ view.
Identification of subclinical disease and its grade in either elbow is the important factor in screening, so the grade of the worst elbow is always quoted as the overall grade and is published on the progeny’s Kennel Club registration documents and in the Kennel Club Breed Records Supplement.
The grading procedure and the records are under continuous review and discussed at the annual CHS scrutineers’ meeting, to enable changes in procedure to be made in light of new orthopaedic research, as well as enabling publication of information for interested parties such as dog breeders and geneticists. The scheme is represented at IEWG meetings so that the UK keeps pace with and participates in international development of management of ED.
The grading system is simple:
0 = Normal
1 = Mild ED
2 = Moderate ED or a primary lesion3 = Severe ED
For further details see www.bva.co.uk/chs
Advice on breeding
The overall grade is used internationally as the basis for breeding advice. Ideally dogs with ‘normal’ (grade 0) elbows should be chosen and at least dogs with 2 or 3 arthrosis should not be used for breeding.
As ED is a prevalent disease, especially in the breeds listed on page 3, such advice will only be effective if it is continued over a number of generations. The most difficult part of accepting such advice for many breeders is that some dogs have never been lame and exercise freely, but nevertheless may have high grades. This is the subclinical population with the ability to pass on the problem in the breed. For long-term control of the disease these dogs ought not to be bred from.
Treatment of clinical ED
Dogs that have clinical ED often become lame between six and 12 months of age. Initially the lameness may be difficult to ascribe to a particular joint. However, at this age a persisting lameness should be investigated by a veterinary surgeon, as other conditions may lead to similar signs.
Diagnosis is normally based on lameness with pain found on flexion and extension of the elbow joint as well as joint enlargement. The animal may have a short or stilted gait as both limbs are often affected. Confirmation of the diagnosis is made by finding primary or secondary lesions on radiographs of the elbow, or by other investigations such as CT or arthroscopy.
Treatment methods vary depending on the nature and severity of the problem. Conservative treatment involving weight restriction and control of exercise is always important. Drugs may be used to relieve pain and inflammation, and may promote repair processes within the joint.
In some dogs, surgery to remove fragments of cartilage and bone from the joint may be advised but this may not always be appropriate. In nearly all cases there will be some secondary changes which lead to further problems in the joint, and may gradually progress throughout the dog’s life and may restrict the dog’s ability to exercise.
However, most dogs will be comfortable with a fair level of exercise if treated carefully during growth between six to 18 months of age. In severe cases it may be
necessary to consider more major surgery.
Getting a dog’s elbows graded
● T he owner should sign the declaration Owners should contact their veterinary (first part) of the certificate, to verify surgeon and arrange an appointment for the details are correct and grant their dog to be radiographed (x-rayed). permission for the use of the results. The radiographs will usually be taken under anaesthesia or heavy sedation so the dog may have to be left at the veterinary practice.
Once the radiographs are taken, Elbow radiographs can be taken at the same time as those for the CHS Hip Dysplasia Scheme. When taking the dog for its radiographs owners should remember the following. to the veterinary surgeon
● The dog must be at least one year owner but there is no upper age limit. surgeon.
● The dog must be permanently and uniquely identified by way of a microchip or tattoo.
● The dog’s KC registration certificate and any related transfer certificates must be available so that the appropriate details can of the original radiographs.
● Microchip/tattoo numbers must also be printed on the radiographs.
● The owner should sign the declaration (first part) of the certificate, to verify that details are corect and grant permission for the use of the results.
Once the radiographs are taken, the veterinary surgeon fils out the appropriate section of the form and submits both the radiographs and the form to the CHS. The results and the radiographs are normally returned to the veterinary surgeon within three weeks with a certifiate for the owner and a copy for the veterinary surgeon. Once a grade has been given for a dog, the radiograph cannot be resubmitted; however, owners have the right to an appeal, which takes the form of a re-appraisal of the original radiographs. A letter of appeal must be made within 45 days of the date of the original certifiate. The whole
procedure from initial appointment to receiving the grades is handled through the submitting veterinary surgeon.
There is a reduced fee when radiographs of the same dog are submitted simultaneously to the CHS for the Hip and Elbow Dysplasia Schemes.
For current fees and further information please contact:
Canine Health Schemes, 7 Mansfield Street, London W1G 9NQ Telephone 020 7908 6380, firstname.lastname@example.org, www.bva.co.uk/chs
The Kennel Club, 1–5 Clarges Street, London W1J 8AB Telephone 0844 4633 980, email@example.com www.thekennelclub.org.uk/doghealth
Original article by Matthew Pead and Sue Guthrie, published in You & Your Vet magazine
Leaflet updated February 2014
Glaucoma is increased pressure within the eye leading to permanent vision impairment. It is an inherited condition in many breeds of dogs and some cat breeds. It also occurs secondary to other ocular disorders such as inflammation, tumors, trauma in all species.
The outlook for preserving vision in eyes with inherited glaucoma is guarded, with early diagnosis and treatment yielding the best results. Diagnosis is made by tonometry – a measurement of intraocular pressure. Management is both medical, using topical pressure control drugs made for people, and surgical, to reduce eye pressure and achieve comfort.
Hip dysplasia (HD) is a common inherited orthopaedic problem of dogs and a wide number of other mammals. Abnormal development of the structures that make up the hip joint leads to subsequent joint deformity. ‘Dysplasia’ means abnormal growth. The developmental changes appear fist and because they are related to growth, they are termed primary changes. Subsequently these changes may lead to excessive wear and tear. The secondary changes may be referred to as (osteo)arthritis (OA), (osteo)arthrosis or degenerative joint disease (DJD).
Later one or both hip joints may become mechanically defective. At this stage the joint(s) may be painful and cause lameness. In extreme cases the dog may find movement very difficult and may suffer considerably.
It was in the light of this knowledge that the British Veterinary Association (BVA) and the Kennel Club (KC) developed a scheme some 40 years ago to assess the degree of hip deformity of dogs using radiography. To date radiographs (X-rays) from more than 250,000 dogs have been assessed providing a standardised reflection of the HD status of those dogs that have been examined. This information is primarily of use for breeders. Currently 126 breeds are surveyed by the scheme in the UK.
Structure and function
The hip joints of land animals and even some birds are remarkably similar. Overall the design has withstood the test of time and is probably close to anatomical perfection. When athletic activity is required, the normal hip is an ideal means of transferring power from the muscles to drive the body forwards with maximum strength and speed. It is the close relationship of the femoral head (ball) and acetabulum (socket) which enables rapid changes of direction. The entire hip joint is a unit comprising the bony structures contained within a joint capsule and supported by ligaments, tendons and muscles together with all their blood vessels and nerves. The large joint surfaces are lubricated by synovial flid. The viscosity (oiliness) of this fluid ensures smooth pain free joint movement. It is not surprising that any variation from this ideal can have severe consequences.
It is argued that dogs are not born with hip joints already affected by dysplasia (unlike humans) but that any faults in development will tend to escalate with time, particularly during the rapid growth phase rom about 14 to 26 weeks of age. However, changes begin as the very young puppy starts to become active and continue until the puppy is skeletally mature. Wear and tear of the deformed joint results in varying amounts of inflmamation and degeneration which lead to more deformity. This progressive deformation is sometimes referred to as remodelling. Some dogs may treble their size and body weight in just three months of adolescence so it is not surprising that there are many critical factors for the puppy at this stage. All the essential nutritional requirements for skeletal growth must be vailable in the right proportions and at the right time. The environment within which the dog is raised, including the type and intensity of exercise, growth rate and body weight are signifiant inflences. However inheritance is a major factor and this is something which we are able to influence by the selection of breeding animals.
As HD can include joint looseness (laxity), inflmmation, pain, new bone formation and bone erosion, it may cause a range of observable signs from normal to minor changes in gait (in the mildly affected cases) to obvious lameness, stiffness after rest and exercise intolerance and pain. As some individuals and breeds may be more stoical than others there is no way of estimating the severity of HD in any dog by observation alone. A veterinary surgeon’s physical examination will provide a more reliable assessment by revealing limitation of joint movement, muscle wasting and pain in the joint(s). Usually a dog with HD does not demonstrate discomfort by yelping, as pain is likely to be dull and continuous rather than sharp and acute. The dog may, though, groan while resting or getting up.
Radiography is the only means of determining the presence or absence of HD. This is an X-ray examination to look at the relative shape and positions of the femoral head and acetabulum and the presence and degree of any secondary changes.
It is known that two factors determine whether HD will occur, and if so, how bad it will be. These are hereditary and ‘environmental’ factors. ‘Hereditary’ relates to the genetic code passed to the offspring by both parents and environmental are all the outside inflences which alter and shape the growth and functions of the bones, cartilage, ligaments, tendons and muscles of the body. In simple terms the genetic code is rather like an architect’s plan (genotype), while the environment is like the builder and his materials (phenotype). In HD the architect has made some errors but the builders have a great influence on how things finally look and function.
It is possible to alleviate some or most of the signs of pain and limitation of movement caused by HD. Sophisticated medications and various surgical procedures are now available. Applied heat, massage, good bedding, exercise and weight management as well as nutrition and physiotherapy also play a part in caring for a dog affected by HD. Professional advice is always necessary to ensure that the best strategy is developed.
Getting a dog’s hips scored
Owners should contact their veterinary surgeon and arrange an appointment for their dog to be radiographed (X-rayed). The radiographs must be taken under anaesthesia or heavy sedation which means that the dog may have to be left for a short time at the veterinary practice. Hip radiographs can be taken at the same time as those for the BVA/KC Elbow Dysplasia Scheme. When taking the dog for its radiographs owners should remember the following.
● The dog must be at least one year old, but there is no upper age limit.
● The dog must be permanently and uniquely identified by way of a microchip or tattoo.
● The dog’s KC registration certificate and any related transfer certificates must be available so that the appropriate details can be printed on the radiographs.
● Microchip/tattoo numbers will also be printed on the radiographs.
● The owner will be asked to sign the declaration (fist part) of the certificate, to verify the details are correct and grant permission for the use of the results.
Once the radiographs have been taken, the veterinary surgeon must fill out the appropriate section of the certificate and submit both the radiographs and the certificate and the current fee to the BVA.
The results and the radiographs are normally returned to the veterinary surgeon within three weeks with a certifiate for the owner and a copy for the veterinary surgeon. Once a score has been given for a dog, the radiograph cannot be resubmitted; however, owners have the right to an appeal, which takes the form of a re-appraisal of the original radiographs. A letter of appeal must be made within 45 days f the date of the original certificate. The whole process from initial appointment to receiving the scores is handled through the submitting veterinary surgeon.
Breed Specific Statistics and Breeding Advice
Hip scoring should be considered along with other criteria as part of a responsible breeding programme, and, ideally, breeders should choose breeding stock with hip scores below the breed median score. The median score is calculated from all the scores recorded for that breed over the previous fie years and is the middle score of the population, i.e. 50% of dogs have a lower score and 50% have a higher score. It therefore represents the hip score of the ‘average dog’ in that breed and dogs with scores which are lower than the median have better than average hips for that breed. It is strongly recommended that hip scores of parents, grandparents, siblings and any previous progeny are considered as this gives the most accurate assessment of an individual dog’s hip status.
The five-year breed mean score (BMS) represents a global numerical average of the scores of all dogs in that breed from the previous fie years. Note that this is not the same as the median, as the figure is biased upwards by the scores of high-scoring dogs. The median score is therefore a better indicator of the average hip status in the breed than the BMS.
The Breed Specific Statistics and a more detailed explanation can be viewed at www.bva.co.uk/chs
Canine Heath Schemes
There is a reduced fee when radiographs of the same dog are submitted simultaneously to the CHS for the Hip and Elbow Dysplasia Schemes.
For current fees and further information please contact:
7 Mansfild Street
London W1G 9NQ
Tel 020 7908 6380
The Kennel Club
1–5 Clarges Street
London W1J 8AB
Tel 0844 4633 980
Use of BVA-KC hip scores
Interpretation and use of BVA/KC hip scores in dogs
Hip dysplasia is a potentially debilitating orthopaedic disease in which laxity of the coxofemoral joint often leads to secondary osteoarthritis, a reduction in joint function and pain. it has been recognised for many years as being of particular importance in pedigree dogs, especially in larger breeds, and is known to be partly governed by genetic factors. in order to try to control canine hip dysplasia and to reduce its incidence, a number of radiographic screening programmes have been developed worldwide. in 1 983, a scheme was established by the British Veterinary association and supported by the
Kennel Club to examine radiographs of dogs’ hips by assessing different anatomical features and giving them a numerical score. this article describes the process of scoring in this scheme, explains how to interpret the score and gives advice on the use of hip scores in the selection of breeding animals.
In the natural ‘wolf’ state, the canine hip is a tight, well-fitting, ball and socket joint that permits full athletic function throughout the animal’s entire life without the development of degenerative change.
Such hips are still the norm in greyhounds, but relatively few other dogs today have such perfect joints. This is probably because domestication has removed the ‘survival of the fittest’ process by which natural selection occurs in the wild and because of selection by breeders for other traits, which has unwittingly perpetuated less than perfect hips.
Laxity of the soft tissues of the joint leads to subluxation or even complete luxation, resulting in abnormal stresses being placed on the bony and soft tissue components of the joint. This, in turn, results in remodelling and in many cases progresses to osteoarthritis . When hip dysplasia is present, secondary changes are likely to worsen with age.
The physical conformation of the hips (phenotype) is influenced partly by environmental factors (eg, weight and diet) and partly by genetic factors (genotype), which are governed by an unknown number of genes. As the condition is polygenic, development of a genetic screening test, while not impossible, lies some way in the future.
Although certain clinical manipulations may indicate whether a hip is markedly loose, it is not usually possible to assess the state of a dog’s hips by clinical examination. Many dogs with hip dysplasia do not show signs of lameness or discomfort until later in life, by which time they may have been used for breeding.
Careful selection of breeding stock is known to reduce the incidence of hip dysplasia in the offspring. At present, such selection is made by assessing the hips of potential sires and dams radiographically.
Requirements for the BVA/KC scheme
Age and identifiation
For submission to the British Veterinary Association (BVA)/Kennel Club (KC) Hip Dysplasia Scheme, dogs must be at least one year of age in order to ensure skeletal maturity, although there is no upper age limit. For dogs intended for breeding, it is essential that the hips are assessed before mating to ensure that they are free of dysplastic changes or only minimally affected.
All dogs must have permanent identification in the form of a microchip or tattoo, and the number must be checked by the veterinary surgeon submitting the radiograph and shown on the image. Most dogs radiographed under the scheme are pedigrees that are registered with the KC, and for these animals the KC registration number must also be shown on the radiograph. However, dogs from any other country, dogs registered with other organisations and unregistered dogs may also be scored, with the images identified appropriately. Radiographs are submitted to the scheme from all over
the world, including from countries where other hip dysplasia schemes are also in operation.
Radiographs are obtained under sedation or anaesthesia for several reasons:
■ To minimise stress to the patient;
■ To permit precise positioning of the pelvis and hips;
■ To remove the need for the animal to be held, as x-rays are potentially hazardous for anyone doing so.
The radiographic view required by the BVA/KC scoring scheme, as for most other hip dysplasia schemes, is the extended ventrodorsal (VD) view. The dog is positioned on its back with its hindlegs extended caudally, resulting in a position similar to that of a standing human. The femora must be positioned parallel to each other and for this the stifles are rotated slightly medially and held in position with a tie or tape so that they lie in the sagittal plane with the patella superimposed over the centre of the distal femur. This position allows the femoral neck to be seen clearly, without superimposition by the greater trochanter, and facilitates the detection of new bone on the femoral neck.
The extended VD position has several advantages:
■ It is easy and safe to achieve;
■ It is very repeatable;
■ It requires no special positioning aids;
■ It gives an excellent view of the hip joint in which
all relevant anatomical areas can be seen.
Centering of the x-ray beam must be at the level of the hip joints, which can be achieved by palpation of bony landmarks such as the pubic symphysis and greater trochanters. Centring further cranially or further caudally will distort the appearance of the hip joints. Collimation must be sufficient to include the pelvis but it is not necessary to include the stifles; to do so requires either incorrect centering or an unacceptably large area to be irradiated.
It is important to avoid tilting the dog to the side (lateral rotation) as this will alter the appearance of the hips and may worsen the score, since the hip that is closer to the table may appear artefactually subluxated. It is also important that the technical quality of the image is of a high standard with optimum contrast and definition and all the necessary labelling. Radiographs that are poorly positioned or which are technically substandard may be rejected if the scrutineers feel that an accurate score cannot be given.
Further details on radiography and submission are given in the BVA’s Guidance Notes for the hip dysplasia scheme.
Hip radiographs are assessed at one or two scoring sessions that are held each week at the BVA’s headquarters in London. Two scrutineers from a panel of 11 examine about 270 sets of radiographs (as printed film or in digital format) during each session, which lasts for several hours, agree on a score and sign the scrutineers’ part of the certificates. All the scrutineers have further qualifications in radiology and/or orthopaedic surgery and have many years of experience in assessing hip radiographs. The whole panel meets annually to discuss matters pertaining to the hip scheme and to review a quality control exercise that runs throughout the year.
What do the hip scores mean?
Each hip (right and left) is examined for nine different anatomical features and a numerical score is given, with points being ascribed to abnormal features . For eight of the features the score may be 0 to 6, and for one the score may be 0 to 5. The total score for each hip is then calculated (range 0 to 53), as is the total hip score (range 0 to 106). Hips with a perfect radiographic appearance score 0; the higher the score, the greater the degree of hip dysplasia ± secondary degenerative change. This scheme therefore allows a wide range of abnormality to be described, unlike some other hip dysplasia schemes in which only a handful of different categories exist.
The nine anatomical features assessed in the
BVA/KC scheme are:
■ Norberg angle;
■ Cranial acetabular edge;
■ Dorsal acetabular edge;
■ Cranial effective acetabular rim;
■ Acetabular fossa;
■ Caudal acetabular edge;
■ Femoral head and neck exostoses;
■ Femoral head recontouring.
These features are shown in a normal hip in Fig 4,
and may be divided into two groups:
■ Those that describe the underlying joint laxity;
■ Those that describe resulting secondary changes.
The first two features – Norberg angle and subluxation – describe the tightness or laxity of the hip joint as demonstrated on the radiograph. The appearance of the cranial acetabular edge may also be affected by subluxation since this widens the joint space between the edge and the femoral head and the two bone surfaces are no longer congruent.
The cranial acetabular edge and the remaining six parameters describe deviations from the ideal ball and socket conformation, ranging from slight changes in the shape of the bones resulting from minor remodelling to severe osteoarthritis. The higher the score in these parameters, the worse the osteoarthritis. Dogs with osteoarthritis should not be used for breeding as they definitely have hip dysplasia; however, not all dogs with lax hips go on to develop osteoarthritis, and it must be noted that the severity of degenerative change also depends on age. Hence, on the scoring certificate many dogs will have scores for the first three parameters with 0 in the remaining sections; this means that the hips show some degree of laxity but as yet no secondary change.
The Norberg angle is a measurement of two hip parameters:
■ The severity of any subluxation;
■ The depth of the acetabulum.
It is measured on film using an orthopaedic anglemeasuring device or a goniometer (specifically a Müller ischiometer [Fig 6], designed for making measurements on human hips), which is laid over the radiograph. The centre of each femoral head is identified and marked with a small dot by finding the best fitting of several concentric circles marked on the ischiometer. The device is then positioned so that the two femoral head centres are joined by a line, and the angle between each centre and the cranial effective acetabular rim is measured. Special computer software has been developed so that the same measurements can be made on digital images. In a good hip, the Norberg angle is 105° or greater (Fig 7). In a hip in which subluxation is present at the time of radiography or in which the acetabulum is shallow, the Norberg angle is reduced, and may even be less than 90° (Fig 7).
Subluxation is assessed by noting the position of the femoral head centre relative to the dorsal acetabular edge and taking into account the congruency of the fit between the femoral head and the cranial acetabular edge. The lower the score, the tighter and more closely fitting is the joint. Scores of 1, 2 and 3 are most common and indicate a less than perfect but reasonable hip, with 3 indicating definite but mild subluxation, since the femoral head centre lies just lateral to the dorsal acetabular edge. Scores of 4 and 5 indicate marked subluxation, while 6 represents complete dislocation.
Subluxation may be a dynamic process, with the hip moving in and out of the acetabulum at different times. It is therefore possible for the degree of subluxation shown on the radiograph to be less than its maximum when the dog is bearing weight and for subluxation to be underestimated. Some critics of the extended hip radiographic view suggest that the extended position tightens the joint capsule and reduces the degree of subluxation, but the number of subluxated hips seen on this view is still large, suggesting that this is not a major effect. The opposite situation cannot occur, that is, a hip that is genuinely tight will not appear subluxated on a radiograph. Clear guidance on the use of the hip score (breed only from dogs with scores well below the breed mean – see below)has taken account of the possibility that the degree of subluxation may be slightly underestimated in some dogs.
Cranial acetabular edge
The cranial acetabular edge is the part of the acetabular margin that is best seen radiographically. It is a continuation of the dorsal acetabular edge and is separated from the caudal acetabular edge by the acetabular fossa. It should be long and gently curving, contouring perfectly to the femoral head so that only a narrow gap is seen between them; this gap is referred to as the ‘joint space’ but consists of both the articular cartilage on the surface of the two bones and the synovial fluid between them. Subluxation and/or remodelling of the cranial acetabular edge causes widening of the joint space medially and/or laterally, resulting in a loss of congruency between the femoral head and the acetabulum.
The most common score for the cranial acetabular edge is 2, which is given when the edge is slightly shorter and straighter than in the perfect hip and/or there is slight loss of congruency between the bones.
Scores of 1 or 2 are commonly seen in otherwise reasonable hips in which subsequent features all score 0. Scores of 3 and above indicate progressively more remodelling of the edge due to abnormal pressure from the femoral head, with scores of 4, 5 and 6 indicating that the acetabulum is markedly deformed. Abnormal subchondral sclerosis is often evident.
Dorsal acetabular edge
The dorsal acetabular edge is the top margin of the acetabulum in the standing animal and is therefore subjected to considerable wear and tear from the femoral head in subluxating hips. On the radiograph it is superimposed by the femoral head and correct radiographic exposure is important to ensure that it is clearly visible. The normal dorsal acetabular edge is a shallow S shape, and scores are given for deviations from this ranging from mild straightening or blurring to irregularity resulting from bone erosion or new bone formation.Scores of 3 and above indicate significant change and are likely to be associated with scores in all or most of the other parameters.
Cranial effective acetabular rim
The cranial effective acetabular rim is not a clearly defined anatomical structure but is the region where the dorsal acetabular edge curves around to become the cranial acetabular edge. It is seen radiographically as an apparently sharp junction between the dorsal and cranial edges and the iliac shaft. This ‘virtual’ structure therefore represents a region that is particularly subject to abnormal wear in loose hips. Abnormalities progress from a slight blurring of the junction to overt wearing away of the bone, producing either a rounded shape or a flattened ‘facet’. In more severe cases, spurs of new bone (osteophytes or exostoses) form at the site of attachment of the joint capsule in response to excessive tension. In the most severe cases, the whole area is remodelled and a defined cranial effective acetabular rim cannot be identified.
Low scores of 1 or 2 are common in otherwise reasonable hips, but scores of 3 and above indicate secondary change and are a component of osteoarthritis.
The acetabular fossa is a roughly circular depression in the depth of the acetabulum and contains the origin of the teres (round) ligament, a short, strong band of tissue that attaches to the femoral head at a slightly flattened area, the fovea capitis. In lax hips, abnormal tension on the teres ligament causes the production of new bone at its origin, resulting in the acetabular fossa losing its clarity.
Any score other than 0 for the acetabular fossa indicates that osteoarthritis appears to be forming and will be associated with positive scores in other features. The fossa may eventually become completely filled with new bone and not be recognisable, giving scores of 5 or 6.
Caudal acetabular edge
The caudal acetabular edge is shorter and less welldefined than the cranial acetabular edge. Its medial end merges with the acetabular fossa and, like the acetabular fossa, any score indicates that osteoarthritis is forming, resulting in a loss of clarity or sclerosis of the edge. Positive scores in other parameters will always be present too.
The maximum score for the caudal acetabular edge is 5, whereas for the other parameters the maximum score is 6.
Femoral head and neck exostoses
The joint capsule is attached to the margin of the acetabulum and around the femoral neck. In the presence of hip laxity, the joint capsule is under abnormal tension and new bone is produced at its attachment to bone, particularly around the femoral neck. The earliest sign of new bone production is the ‘Morgan line’ or caudal curvilinear osteophyte, which extends a little way down the femoral neck and produces a fine, curving, radiopaque line; this is scored 1. As more new bone is produced on the femoral neck, it may be seen on the skyline (score 2), progressing to a ring and then a collar of new bone (scores 3 and 4, respectively).
Continued development of these osteophytes encircling the femoral neck causes increasing distortion, with the proximal femur having a mushroom shape and scoring 5 or 6.
A score of 2 or more in this category indicates that osteoarthritis is definitely developing and is likely to worsen with age.
Femoral head recontouring
The normal femoral head, as mentioned above, is rounded, with a small, flattened area for attachment of the teres ligament. When marked hip dysplasia is present, continued instability of the joint causes the femoral head to change its shape progressively, and any deviation from its normal shape is scored as recontouring (remodelling). Severe recontouring is mainly seen in older dogs in which the changes have progressed further, but may also be seen in young dogs with complete luxation or severe subluxation, since the bones have never developed normally.
While it is impossible to correlate a hip score exactly with grades of hip dysplasia given under other schemes, an approximate interpretation for total hip scores is as follows (assuming that the two hips are similar):
■ 0 to 4 total score: perfect or near perfect hips
■ 5 to 10 total score: borderline changes that are
unlikely to worsen with age
■ 11 to 20 total score: mild changes that may worsen
with age, sometimes developing into osteoarthritis
■ 21 to 50 total score: moderate to marked hip dysplasia in which osteoarthritis is already a prominent feature, or severe hip dysplasia before arthritic
■ Above 50: severe to very severe osteoarthritis
secondary to hip dysplasia
If the scores of the two hips are markedly different, the worse of the two hips should be considered to be more representative of the dog’s hip status, and doubling that single hip score will give a more realistic overall score for the purposes of selection for breeding. For example, a dog with a score of 12:3 should be considered to have a hip status similar to other dogs with a total score in the mid-20s.
Effect of age
It is known that age usually has an effect on less than perfect hips, as do environmental factors such as bodyweight, but for logistical reasons it is impossible to demand that all dogs are the same age at radiography for scoring. In the USA, dogs must be at least two years of age for radiography under the Orthopedic Foundation for Animals (OFA) scheme; in the UK, the minimum age is one year for historical reasons and would now be difficult to change. Clearly, breeding dogs should be radiographed before the first mating, but generally the younger a dog is at the time of radiography the less time
there has been for the manifestation of age and environmental effects. Therefore, the presence of arthritic change in a young dog should be considered particularly significant and these animals should definitely be excluded from breeding.
In dogs without evidence of osteoarthritis, consideration of the Norberg angle and subluxation is particularly important. Hips with a total score higher than about 12 to 15 are likely to worsen with time and so when comparing different dogs, their age at radiography should be taken into consideration. Nevertheless, radiographs of older dogs often show marked subluxation with absent or minimal secondary osteoarthritis, and so development of degenerative change is not inevitable.
This indicates that joint laxity is not necessarily an accurate predictor of future osteoarthritis in an individual dog, although the relative influence of genetic versus environmental factors for this is not known.
A number of epidemiological and genetic studies have been carried out using information from extended hip radiographs, both in the UK using the BVA/KC’s scoring scheme data and in other countries where alternative hip dysplasia assessment schemes exist. Some of these publications have examined not only the overall hip status but also component features of the radiographic appearance of the hip (Wood and others 2000a, 2002, Ohlerth and others 2001, Zhang and others 2009, Lewis and others 2010b). A wide variety of dog breeds have been included in these studies, and many instances of an improvement in hip dysplasia prevalence within a breed are documented, even where breeding selection pressure has not been rigid. In Sweden it has been mandatory since 1984 to know the hip status of both a sire and dam if their offspring are to be registered with the Swedish Kennel Club; this has led to a shift towards using dogs with better hips and a corresponding decrease in the prevalence of hip dysplasia in seven breeds studied: German shepherd dog, golden retriever, labrador retriever, Newfoundland, rottweiler, Bernese mountain dog and Saint Bernard (Swenson and others
1997). Statistical modelling has shown a strong, positive relationship between the hip scores of parents, grandparents and offspring, indicating that the genetic heritability of hip dysplasia is moderate to high (Wood and others 2000a,b, 2002). In particular, total hip score, Norberg angle and subluxation have been found to have significant heritability in a number of different studies (Wood and others 2000a,b, Ohlerth and others 2001, Zhang and others 2009, Lewis and others 2010b). This confirms that, overall, the extended VD radiographic view is a fairly reliable way of demonstrating the
presence or absence of subluxation.
Norberg angle, subluxation and cranial acetabular edge have also been shown to be predictive of osteoarthritis in later life, although the heritability of such degenerative change has been shown to be more modest (Lewis and others 2010b). In breeds for which the effect of both the sire and dam has been examined, heritability has been shown to be higher from dams in flatcoated retrievers, Gordon setters and Newfoundlands (Wood and others 2000a,b) and from sires in labrador retrievers (Wood and others 2002). In practice, it may be that breeders are taking more care with their choice of sire, whereas in fact the dam’s influence on its offspring’s hip status may be larger in some breeds. Use of the hip score A major advantage of the BVA/KC scoring scheme is that it is possible to calculate an average (mean) score for each individual dog breed, and thus to evaluate a dog’s hip status relative to others in its breed.
This compensates for the fact that some breeds tend to have a relatively low incidence of hip dysplasia (eg, flat-coated retrievers and many of the sight hounds), whereas hip dysplasia is much more prevalent in other breeds (eg, otter hound, Sussex and clumber spaniels, Newfoundlands). Breed mean scores (BMSs) for most breeds have been published regularly by the BVA and are available on the Canine Health Schemes section of the BVA website. When selecting a dog for breeding, the traditional advice has been that only dogs with hip scores well below the BMS should be chosen in order to apply meaningful selection pressure. Ideally, only dogs with total scores of 10 or less should be used for breeding and, more specifically, when these scores arise only from parameters 1 to 3, with a 0 score for parameters 4 to 9 (ie, no detectable osteoarthritis). This is because total hip score, Norberg angle and subluxation have the highest heritability (Wood and others 2000a,b, 2002, Ohlerth and others 2001, Zhang and others 2009, Lewis and others 2010b), whereas secondary change is more likely to be influenced by age and environmental factors. In addition, a dog’s own score should not be considered in isolation, but scores from its relatives should also be sought. These include the scores of its parents and grandparents, scores of other offspring from either parent (progeny testing, usually relating to sires) and scores from any siblings. Genetic research has shown that by considering scores from as many relatives as possible, the influence of environmental factors is minimised and the
most accurate assessment of genotype is given. This is borne out in practice by certain breeds and lines of dogs in which good selection pressure has been applied and in which the incidence of hip dysplasia is now very low. A progressive reduction in BMS has been seen in the majority of UK breeds for which it has been calculated, but the reduction would be more marked if breeders practised a more rigid selection process
Limitations of the BMS
The BMSs published are calculated as the average scores for all dogs submitted to the BVA/KC scheme since its inception in 1983, and in some cases are averaged over a very large number of dogs (eg, approximately 70,000 labrador retrievers). As a result, the published BMS does not necessarily reflect the precise current hip status in the breed, and downward or upward trends are not shown since the current hip scores are ‘diluted’ by scores of dogs from many previous generations. To overcome this, five-year rolling mean scores (the BMS for periods of the preceding five years) were initially
produced for a number of the most popular breeds, and these show a convincing and steady reduction in hip score indicating an improvement in the hip status of these breeds Five-year rolling
means are now being published for most breeds. One criticism sometimes levelled at the BVA/KC scoring scheme is that, due to the impossibility of enforcement, it is not mandatory for all hip radiographs obtained to be submitted, so the true hip status of a breed may not be represented. It is possible that greater selection of submitted radiographs is being performed by submitting vets, although this seems unlikely based on the number of submissions received by the BVA and the increasing public awareness of the importance of the Canine Health Schemes. The BVA emphasises the importance of submitting all hip radiographs, regardless of the likely score. However, if it is assumed that generally it is the radiographs of the worst hips that are not submitted and that this has not
changed with time (because the vet and owner can see that they are likely to receive a high score and the dog is therefore not going to be used for breeding), the calculated BMS is biased downwards and this increases the selection pressure applied.
Introduction of the breed median score
The BMS, being the average score in a system in which dysplastic hips score higher than normal hips, is distorted upwards by very high scores of a relatively few, severely affected individuals. Thus, a dog with a score at or close to the breed mean is actually in the worse half of the breed. Several years ago it was realised that a more meaningful number was the median, that is, the score of the average or middle dog (not the same as the average score), at which equal numbers of dogs are both less severely and more severely affected. The median hip score for a breed is inevitably lower than the BMS over a given period of time, usually by several points. For example, the median score of the labrador retriever was 10 at a time when the BMS was 16, and therefore only those with scores below 10 would have been preferred for breeding. Breed median scores are now generated and additional advice for vets and breeders is that only dogs with scores below the median should be used for breeding (that is, the dog is in the better 50 per cent of the breed). This will apply more meaningful selection pressure, although some breeder education will be required to convey the difference between the BMS and breed median score.
Ovarian cysts may affect female dogs and are not a life threatening condition. Ovarian cysts rarely turn into malignant tumors, but the cysts should be monitored periodically. If the cysts don’t cause any discomfort and the dog is not used for breeding purposes, the cysts don’t require surgery or any type of treatment.
Causes of Ovarian Cysts
The causes of canine ovarian cysts are not known. Some vets will attribute the formation of ovarian cysts to a recent estrus or to hormonal changes (i.e. an excess of estrogen). However, the condition may also be idiopathic. Unspayed female dogs are more likely to have ovarian cysts.
Types of Ovarian Cysts
There are several types of ovarian cysts in canines including:
• Follicular cysts
• Epithelial cysts, that involve tissues
• Stromal cysts, which involve the connective tissues
Symptoms of Ovarian Cysts
The symptoms of ovarian cysts will depend on the type of cyst found in the dog. If the dog has a follicular cyst, he may display the following symptoms:
• Swelling of the vulva, due to the high amounts of estrogen in the dog’s body
• Vulvar discharges that may contain blood and occur outside the regular bleeding in the heat cycle
• Hair loss
If the dog is affected by an epithelial or stromal cyst, there may be symptoms such as:
• Irregular heat cycles or lack of heat cycles
• Extended heat cycles
• Hair loss
• Abdominal swelling due to pus or fluid accumulation in the abdominal cavity
Some dogs with ovarian cysts may not present any symptoms.
Diagnosing Dog Ovarian Cysts
A physical exam will be needed and blood tests will be performed. X-rays and ultrasounds will be needed to detect the location and the size of the cysts. The vet will have to rule out ovarian tumors, which often present the same symptoms. The only way to differentiate between a benign growth such as a cyst and a malignant tumor is to have a biopsy. A small sample of tissues will be analyzed under the microscope and the vet will see if the cells are malignant.
Treatment Options for Ovarian Cysts in Dogs
The ovarian cysts are typically benign formations and will not turn into malignant tumors (with rare exceptions). Consequently, the ovarian cysts may not need surgical removal. Surgery will only be recommended if the cysts seem to grow rapidly and may affect other organs in the abdominal cavity. The presence of a cyst may interfere with the dog’s fertility and should be removed if you want to breed the dog. If the cyst is not removed, the dog should be monitored and she should get regular x-rays and ultrasounds to establish if the cysts grow or transform in any way. In many cases, the ovarian cysts disappear without any treatment. In other cases, the vet may recommend hormonal therapy to reestablish the hormonal balance, which can also eliminate the cysts.
The term “pyometra” refers to a potentially fatal condition in which the uterus becomes infected and gradually fills with pus. Many dog owners are unaware of this disease, yet veterinary professionals know the signs all too well: behavioural changes including lethargy, increased thirst, increased urination and loss of appetite are amongst the earliest symptoms. As the infection festers, abdominal bloating and/or oozing discharge from the vulva may be noticeable. Without prompt veterinary attention, your pet could quickly deteriorate and die from infection or a rupture of the uterine walls. You may be wondering: what causes this horrible condition and why is it so dangerous? How is pyometra treated once it’s been diagnosed? How can I prevent my dog from having pyometra? Read on for answers.
Causes and types of Pyometra
Pyometra develops after bacteria infiltrate the uterus through the cervix, which opens during the heat cycle and following pregnancy. Infection can occur in female mammals of any age, but your dog may be especially susceptible if she has not been spayed, is middle aged or older, or regularly receives hormonal treatments (i.e. misalliance injections, heat suppression injections). Bitches that meet one or more of the above criteria should be monitored especially closely in the weeks after their season and/or after giving birth, as they will be most vulnerable at these times.
There are three different types of pyometra:
• Closed – this is an extremely dangerous condition in which the closure of the cervix causes pus to pool in the uterus with no escape. As this happens your dog may become increasingly “off” and her symptoms may worsen over a short period of time. Because there is no discharge and other symptoms of infection aren’t easily noticeable, owners may decide to wait it out before seeking veterinary attention. Unfortunately, this increases the risk that uterus will continuously expand and eventually rupture within the body, or that the kidneys will fail. Up to 1/3 of pyometra victims will fall into this category.
• Open – this type of pyometra occurs when the cervix remains open following infection. There will usually be tell-tale discharge around the vulva, however this can easily be mistaken as a continuation of the heat cycle. Though the uterus may not swell or expand, an open pyometra is still classed as an emergency due to the threat of organ damage – especially to the kidneys. The sooner your pet receives veterinary attention the better the prognosis will be.
• Stump- though rare, a stump pyometra is dangerous in that it is often unexpected: it occurs in spayed animals. Unbeknownst to many owners, stump infections may occur in remnants of tissue left behind during a routine spay, which fill with infected fluid. The symptoms and risks are similar to those of a true pyometra, therefore it is important that owners of spayed pets consult their vet as soon as any of the previously-mentioned symptoms crop up.
Uterine infections are dangerous not only because they may cause the uterus to rupture, but also due to the effect they have on the organs – especially the kidneys. Bitches experiencing a uterine infection will drink more water as the formation of immune complexes reduces the ability of the kidneys to absorb water. The result is dehydration, which in and of itself is a considerable health threat, and the risk of eventual kidney or renal failure. This fact plays a role in the type of treatment your pet will receive, as will be discussed in the next section.
The most common form of treatment for pyometra is an emergency ovariohysterectomy or spay, meaning that the veterinary surgeon will remove the ovaries and uterus to prevent the latter from rupturing. Before a positive diagnosis is made, your vet will need to examine your bitch to determine whether the cervix is open or closed, as well as how advanced the infection has become. The condition of your pet will determine the next step. In some instances, your vet will make the diagnosis just by feeling the dog’s uterus through her abdomen, but ultrasound and x-ray may also be used. Sometimes blood tests will be run in order to confirm the presence of white blood cells – a hallmark of infection. If the infection is caught early enough it may be possible to treat it medically with antibiotics. In severe cases, the patient will go straight to the operating prep room post-diagnosis, day or night. A successful spay at this phase is not synonymous with survival: advanced infection may damage the vital organs to the extent that they never recover. Therefore, your vet will take necessary precautions to ensure that your pet is protected from the effects of the anaesthetic agents and surgery itself.
As you probably will have guessed, emergency veterinary surgery is far more expensive than a routine spay.
Prevention of Pyometra
The good news is that pyometra is preventable. If your dog is successfully spayed before her first season, she will be best protected from this and many other reproductive diseases. It is also worth considering that a young, healthy dog is more likely to have an easy recovery than an older bitch following a spay operation. Owners of breeding bitches can still protect their valuable pets by tracking their seasons and closely monitoring any changes in behaviour.
Subaortic stenosis is a narrowing (stenosis) of the area underneath, the aortic valve, that causes some degree of obstruction or blockage of the blood flow through the heart. The narrowing can be mild, moderate, or severe; if moderate or severe, it can force the heart to work harder and potentially be harmful to the heart’s health.
It most commonly occurs in large-breed dogs. Subaortic stenosis appears to be genetic in origin; the first signs of it may be present at birth (moderate or severe cases) or may appear in the first year of life (usually milder cases).
In mild sub-aortic stenosis no signs are observed. In moderate (sometimes) and severe (almost always) cases, symptoms such as weakness, breathing difficulty (dyspnea), fainting (syncope), and, in extreme cases, sudden death are all possible as a result of subaortic stenosis. Realize that dogs with subaortic stenosis, even severe subaortic stenosis, may look perfectly healthy and active. These dogs generally do not realize that their hearts are compromised.
Your veterinarian will perform a thorough physical examination (including listening carefully with a stethoscope for a heart murmur or irregular heartbeat) and ask you whether you have seen any of the symptoms described above.
• Chest x-rays are useful if symptoms such as labored breathing are present because dogs can develop laboured breathing for many reasons, not just subaortic stenosis. Chest x-rays can show the telltale signs, such as fluid accumulation in the lung tissue in severe cases.
• An electrocardiogram (ECG) depicts the pattern of electrical activity in the heart and any irregularities in the heart’s rhythm (arrhythmias).
• An echocardiogram (cardiac ultrasound) is the test of choice for subaortic stenosis. An image of the inside of the heart is displayed on a monitor in real time. This test allows the veterinarian to assess the valves (including any narrowing), blood flow patterns and velocity, degree of stenosis (i.e., extent of blockage), and other aspects of cardiac structure and function. The degree of severity is assessed using several components of the ultrasound exam, especially Doppler ultrasound, which measures the direction and flow of blood as it courses through the heart.
Mild subaortic stenosis is of no consequence to an individual dog. Moderate or severe subaortic stenosis may cause symptoms and may increase the risk of sudden death. Depending on the exact degree of severity, treatment may be required, and other measures (such as limiting activity) may be recommended to minimize the amount of work done by the heart. There is no cure for subaortic stenosis. Since it is thought to be of genetic origin it is often recommended that dogs with subaortic stenosis are not be bred from to avoid passing the disease along to future generations.
If the disease is mild, treatment is not required. However, subaortic stenosis can get worse as a growing dog reaches its adult age and body size. Therefore, dogs with moderate or severe subaortic stenosis may require medication. The most common form of treatment is a medication given orally called βeta blockers, which reduce the intensity of the heart’s work, help to prevent the heart from beating too fast and can control arrhythmias. If your dog has been found to have moderate or severe subaortic stenosis, it is important to reduce the workload on the heart (and therefore to decrease the risk of sudden, collapse, fainting, or even sudden death) by controlling or avoiding bursts of sudden activity or any intense exertion.
Several surgical procedures and minimally invasive (balloon catheterization) procedures have been performed to reduce the obstruction of sub aortic stenosis with variable success. However, recently a new technique has become available utilizing a special “cutting” balloon, which appears to have favourable results.
Hypothyroidism is a common disease in dogs. The thyroid gland has a number of different functions, but it is most well known for its role in regulating metabolism by producing thyroid hormones. Hypothyroidism is the condition that occurs when not enough thyroid hormones are produced. Hypothyroidism causes a wide variety of symptoms, but is often suspected in dogs that have trouble with weight gain or obesity and suffer from hair loss and skin problems. Hypothyroidism is easy to diagnose with a blood test that checks the level of various thyroid hormones including T4. Most hypothyroid dogs respond readily to treatment with synthetic thyroid medication. Many dogs suffer from a low thyroid hormone level for years without treatment. If your dog has chronic recurrent skin problems, or unexplained weight gain, she may be suffering from hypothyroidism.
What causes hypothyroidism?
The thyroid gland is a small gland that is situated close to the larynx (voice box) in the neck.It is regulated by the small pituitary gland that is located at the base of the brain. Normally, the pituitary gland produces a hormone called TSH (thyroid stimulating hormone). This hormone tells the thyroid gland to produce thyroid hormone. The amount of TSH produced is dependent on the amount of thyroid hormone in the blood. The pituitary gland responds to the blood level of thyroid hormone by producing more TSH if the thyroid hormone level is low, and less TSH if the thyroid hormone level is high.
Hypothyroidism results from the impaired production and secretion of thyroid hormones. More than 95% of all cases occur as a result of destruction of the thyroid gland. Most hypothyroidism is due to thyroid gland destruction that is suspected to be caused by the dog’s own immune system killing the cells of the thyroid gland. Hypothyroidism may also be a result of atrophy of the thyroid tissue and resultant infiltration of the tissue by fat, or by a cancer. Hypothyroidism can also be associated with the presence of other diseases and the use of certain medications. Rare cases of congenital hypothyroidism have been diagnosed, as well.
Who gets hypothyroidism?
Although the onset of clinical signs is variable, hypothyroidism most commonly develops in middle-aged dogs between the ages of 4 to 10 years. The disorder usually affects mid to large size breeds of dogs, and is rare in toy and miniature breeds of dogs. Breeds that appear to be predisposed to developing the condition include the Golden Retriever, Doberman Pinscher, Irish Setter, Miniature Schnauzer, Dachshund, Cocker Spaniel, and Airedale Terrier. German Shepherds and mixed breeds appear to be at a reduced risk of contracting the disease. There does not appear to be a sex predilection but spayed females appear to develop it more often than intact females.
What are the symptoms?
Thyroid hormones are needed for normal cellular metabolic function. A deficiency of thyroid hormones affects the metabolic function of all organ systems. As a result, the symptoms are usually variable and non-specific. There is not a specific symptom that is diagnostic for hypothyroidism. There are, however, several symptoms that when combined together make the veterinarian more suspicious of the likelihood of the animal having the disease. A study on hypothyroid dogs revealed the following information on the variety and frequency of symptoms seen with the disease:
|Clinical Symptoms||% of Dogs Showing Symptoms|
|Dry hair coat/excessive shedding||60|
|Hyperpigmentation of the skin||25|
|Slow heart rate||10|
|High blood cholesterol||80|
How is hypothyroidism diagnosed?
There are several different tests used to diagnose hypothyroidism in the dog. The test chosen will depend on the symptoms and the availability of different tests to your veterinarian.
Baseline T4 Test: The most common test run is the baseline T4 test. A blood sample is drawn and tested by radioimmunoassay to determine the level of T4 thyroid hormone in the bloodstream. The T4 hormone is produced only in the thyroid gland and dogs with a failure of the thyroid gland will have a lowered level of this hormone. However, there are other conditions that can cause a lowering of T4 so if this screening test is positive for hypothyroidism another more specific test is often done to confirm the diagnosis.
Free T4 by Equilibrium Dialysis: T4 is present in two forms in the body. The “bound” form is attached to proteins in the blood and is unable to enter the cells. The “free” T4 is not attached to proteins, and can readily enter the cells and perform its function. The free T4 is normally present in very small amounts. A special laboratory test – equilibrium dialysis – has been designed that can quite precisely measure free T4.
TSH Level: This blood test measures the amount of TSH in the bloodstream. In a hypothyroid dog, the level will be elevated because the body is trying to stimulate the thyroid gland to produce more thyroid hormone. If the Baseline T4 and Free T4 by Equilibrium Dialysis are low and the TSH is elevated, a diagnosis of hypothyroidism can be made.
TSH Response Test: If a dog has a low T4 level, this test may be performed to confirm a diagnosis of hypothyroidism. A small amount of Thyroid Stimulating Hormone (TSH) is injected into the vein. After 6 hours, a blood sample is drawn and the T4 level is checked. A dog without thyroid disease that may have other conditions causing a low T4 will have a high T4 level after the TSH injection. A dog with true hypothyroidism will not have an increase in T4 after the injection.
How is hypothyroidism treated?
Hypothyroidism in dogs is easily treated. Treatment consists of placing the dog on a daily dose of a synthetic thyroid hormone called thyroxine (levothyroxine). There are numerous brand names of this drug. The dose and frequency of administration of this drug varies depending on the severity of the disease and the individual response of the animal to the drug. A dog is usually placed on a standard dose for his weight and then blood samples are drawn periodically to check his response and then the dose is adjusted accordingly. Once therapy is started, the dog will need to be on treatment for the rest of his life. Usually after the treatment is started, the majority of the symptoms resolve themselves.