Factsheet: Health Tests a Breeder Should Know About

Unfortunately, many pedigree dogs are prone to a range of hereditary diseases and defects and a good breeder should only ever breed from dogs that have been tested to prove their healthy credentials. (What’s more - a sensible person should only buy a puppy from a breeder who performs such health screening tests on their breeding stock!)

Therefore a good, responsible breeder should be aware of the common health tests relevant to their breed. Here is a selection:

Hip Scoring

What for: Hip dysplasia (also known as degenerative joint disease) is a genetic disease which leads to abnormal formation of the hip socket and is one of the most common hereditary problems affecting dogs. It causes terrible pain and suffering on the part of the dog, leading to gradual debilitation until the everyday activities become too painful and the dog is not even able to walk. It is not a disease of old dogs either – dogs as young as 6 months have been diagnosed with hip dysplasia, although in most cases, symptoms will not start developing until the puppy has matured.

The Test: The best way to prevent hip dysplasia is to only buy a puppy from parents whose hips have been hip scored. This is a screening test which assesses a dog’s hips through radiographs and then scores them, from 0 (best) to 106 (worst). Each breed will have an average score and a breed with a higher mean score has a higher tendency towards hip dysplasia, compared to one with a lower score. Regardless of your breed’s mean score, you want a puppy whose parents had hip scores well beneath their breed average.

Watch out: Reputable breeders always hip score their dogs and should offer to show certification to prospective puppy owners. (Don’t believe breeders who say that they can tell their dogs have good hips “just by looking” – a dog may be active and mobile for several years before developing hip dysplasia – this still means that he/she can pass the potential for this debilitating illness onto their puppies.)

Cardiac Testing

What for: Inherited heart defects are common in many breeds, such as Boxers, Cavalier King Charles Spaniels, Great Danes and many toy breeds. Owners of affected dogs will often have to watch their beloved pets endure a slow, painful death – or face the decision of putting their pets to sleep. Therefore, it is vital that any breeder of a breed known to have hereditary heart conditions only breeds from stock that have been heart-tested and are healthy.

The most common heart conditions are aortic stenosis and sub-aortic stenosis, patent ductus arteriosus, dilated cardiomyopathy and mitral valve disease.

The Test: Unlike hip dysplasia, there is no single, independent heart-testing scheme at the moment but individual breeds that are prone to heart defects will have their own club-organised schemes, which all reputable breeders will participate in. In general, testing the heart involves listening with a stethoscope by an experienced vet, using an electrocardiogram and using an echocardiogram to try and detect cardiac abnormalities.

Watch out: One problem with heart conditions is that they often don’t present until later in life, therefore a dog that has been tested as normal and healthy (and is therefore used for breeding) can develop heart disease when it gets older, by which time it is too late as it has already passed its genes onto its puppies. Therefore, even the most responsible breeders can sometimes find it hard to screen for these conditions. However, it is still a good idea to buy from breeders who are aware of these tests and who make every effort to test their breeding stock.

Eye Testing

What for: Many breeds suffer from a range of congenital eye conditions, from small distortions of the eye structures (e.g. collie eye anomaly) to more serious problems causing severe pain and blindness, such as persistent hyperplastic primary vitreous (PHPV) and persistent papillary membrane (PPM). The breeds with a higher incidence of hereditary eye problems include the Siberian Husky, retriever breeds, Sealyham Terrier, collie breeds, poodles (all three sizes), Welsh Corgi, Staffordshire Bull Terrier, spaniel breeds, Miniature Schnauzer and others.

The Test: Most genetic eye conditions can be picked up in puppies and so can be diagnosed between 6 and 12 weeks. These include conditions like multifocal retinal dysplasia, congenital hereditary cataract and persistent hyperplastic primary vitreous.

The Kennel Club and the British Veterinary Association have developed screening tests for 11 eye conditions (which are known to affect over 50 dog breeds) and any reputable breeder should test their breeding stock before producing any puppies.

Watch out: Like heart conditions, many eye conditions are late-onset so it is advisable for breeders to perform annual eye tests on their breeding stock so that they do not inadvertently use a dog for breeding which might be carrying a defective gene.

Testing for Syringomyelia

What for: a hereditary disease which is particularly in small breeds, syringomyelia is also known as the “neck-scratcher’s disease” because it causes the dog to scratch excessively in the area near the neck. Dogs with syingomyelia suffer a lot of pain and can become very disabled, causing a lot of distress to themselves and their owners. In serious cases, parts of the spinal cord become destroyed and the dog cannot eat or sleep unless its head is held high, while simultaneously losing power in their legs until they become paralysed.

The Test: despite being such a horrible disease, it is easily preventable by breeders being responsible and making sure that they screen all breeding stock. Puppies can screened as early as 6 months old but it is better to wait until the dog is at least 2 and a half years old because this disease can also be late-onset.

Watch out: although most dogs will show symptoms by 3 years of age, some dogs may be silent carriers of the disease and therefore it is essential that all breeding stock are thoroughly screened to make sure that they do not pass on any defective genes to puppies.