Health Testing Explained

At around a year of age, when the dog’s skeleton has fully grown, an x-ray is taken of the dog’s pelvis area. This x-ray is then sent from the vet to the BVA (British Vet Association). They will score this x-ray with each hip of the two hips scoring between 0 (lowest) and 53 (highest). So if both hips are scored the total that dog achieves will be between a TOTAL of 0 and 106 (2 x 53). Currently the breed average for a total of both hips sits at around 16. So dogs around or under this score have average or better than average hips to give a guide. The score can also be shown sometimes as two numbers, left hip/right hip - so, something like 5/4 (total of 9 - good) or maybe 33/21 (total of 54 - poor).

To recap, it is the PARENTS of the litter who are scored and not the puppies. This cannot be undertaken until a year of age as a minimum but can be done at any age after this. Only dogs to be bred from are usually hip scored, there is no need to score pet puppies not to be bred from. The information is FOR breeder and puppy buyers to decide if the dog is suitable to be bred from. Hip scoring is done once in a dog’s life only and his score remains with him for the rest of his life

The BVA/KC eye testing scheme has been around for about 25 years or so now. It has been tweaked and fine-tuned and moved about but the general idea of it has remained the same. That if a dog is examined by an expert for the eye conditions which are common to Labradors, and is clear (or 'unaffected' as it is sometimes described) then one can mate in safety to another dog, also carrying a current clear eye certificate and know you are doing the best possible by the puppies produced for future good eye health.

However eyebrows were raised when two dogs with clear eye certificates were mated, a puppy from that was tested at 2, 3 or more years of age, and FAILED his own eye certificate. How can that be? Well, the answer is simple and that is that both his parents although clear themselves were genetically CARRIERS of the eye problem he failed on and so, when put, perfectly ethically together, were always going to produce a proportion of pups affected with the most nasty of all eye problems, Late Onset PRA or GPRA as it is better known.

So work was started on a DNA test which would show not only if the parents were affected or unaffected with GPRA but ALSO, importantly, the result the paper BVA/KC eye test itself couldn't see, if they were Carriers.

After many years of waiting we finally have a test, run by the company 'Optigen' in the United States, to exactly as above, give the GENETIC eye status of any dog before breeding from it.

Results will return as your dog being either: Clear, Carrier or Affected.

This test is not to rule any dog out of the gene pool, but to give us a clearer idea of the playing field and to be able to make breeding decisions accordingly.

The various breeding combinations using Optigen results are:

Clear x Clear = 100% Clear offspring
Clear x Carrier = 50% Clear 50% Carrier offspring
Carrier x Carrier = 25% Clear 25% Affected 50% Carrier Offspring
Clear x Affected = 100% Carrier offspring

So you can see that when Optigen tested, even a AFFECTED dog could be mated to a clear dog and never produce a single puppy who will be affected by GPRA.

Indeed because you can Optigen test from a very young age, literally from 6/7 weeks of age, if you undertake a Carrier x Clear mating, and don't wish to keep a Carrier puppy, you can Optigen test the best two or three pups (at a reduced rate for this what is called 'litter testing') and keep only a clear puppy. The Carrier pups will never develop the problem, of that you can be CERTAIN, and so can be sold as pets comfortably.

Copyright Diana Stevens, Wylanbriar Labradors 2007

In the past this was often known as Labrador Myopathy, and was first identified in the 1970’s. But it’s name was later changed when it was realised that there were great similarities with a human disease which was called Centronuclear Myopathy! The name was coined because far more than normal of the nucleus of the cells in the muscles are central.

Dogs affected appear perfectly normal at birth, starting to show signs of the weakening muscles at around 2 to 5 months of age. Often the first sign is a “Bunny hopping “ gait, often making people think “Hip Dysplasia,” But as the disease develops it involves muscle weakening of the whole dog. The severity can be so bad that the only option available is euthanasia, but in less severely affected dogs it is possible that they can continue to live out their full lives, although they will continue to show exercise intolerance. This is often worse in cold weather. But the bottom line is that they will not get better and there is no cure. Although not widely spread it is a very distressing disease.  

Because there are several different diseases which can give vaguely similar symptoms, it was not until the advent of the DNA test that we had a reliable way of easily identifying dogs suffering this disease. But although the DNA test can be used as a diagnostic tool for collapsing dogs, it’s real beauty is as a screening tool to prevent the disease occurring. The procedure is very simple, entailing collecting a DNA sample from inside the cheek of the dog on a sterile swab which is available from the “Animal Health Trust” in Newmarket, who will then carry out the test on the swabs returned to them. The test is not expensive, at the time of writing this just £42.

The disease is carried as a simple recessive gene so carriers will not develop the disease and can be mated to dogs which have been tested clear of CNM, in the knowledge than no pup will ever develop the disease. So by testing it is possible to prevent CNM from raising its head ever again.

Copyright John Weller 2010