Ataxia Test Submission to Dogs NSW

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Due to the recent ability to test dogs for this terrible hereditary disease The American Staffordshire Terrier Club of NSW Inc has forwarded the following submission to Dogs NSW in the hope to have mandatory Ataxia testing implemented for all registered breeders in Australia. Each state breed club and Amstaff breeders across Australia will have the opportunity to reply with their thoughts and opinions on this submission in due course.

The purpose of this test being introduced as mandatory is in aid to prevent there from being any further Amstaffs in Australia suffering this terrible illness and to assist all potential Amstaff owners to make a more informed decision when purchasing their Amstaffs. 

Attn: Dogs NSW Board of Directors

Re: Introduction of mandatory health testing for hereditary Cerebellar Ataxia in the American Staffordshire Terrier.

To The Secretary;

The American Staffordshire Terrier Club of NSW Inc would like to put a submission forward; To introduce mandatory DNA testing for a debilitating hereditary disorder in the American Staffordshire Terrier called Cerebellar Ataxia, for which a DNA marker has been recently found with ANTAGENE in France.

Many breeders worldwide including in Australia have already started testing their dogs for this disorder, however we would like to see ultimately that this becomes something all breeders do.

What is Cerebella Ataxia

Cerebellar Ataxia is an autosomal recessive neurological disease. The first signs of the disease usually appear between 3 and 5 years of age in affected dogs. They are: loss of balance, difficulty cornering, and falling when shaking their head. As the signs progress, most dogs seem to have difficulty initiating movements. When they become unable to walk without falling repeatedly, owners usually make the difficult choice to euthanize.

The incidence of Cerebellar Ataxia has increased greatly in the last few years due to affected dogs being bred before they exhibited the first symptoms.

Until the availability of this new DNA test, it was also impossible to detect carriers. Two carriers when bred together produce litters that have the potential of producing affected dogs also.

For a dog to develop this disease they must inherit two defective copies of the gene (1 from each parent).

Diagnosis

ANTAGENE, a DNA research laboratory in France, has commercialised a DNA test that detects Cerebellar Ataxia in American Staffordshire Terriers. The test identifies the following:

Identification of the implicated gene and validation of the test resulted from collaborative research efforts between the laboratory of Molecular and Cellular Genetics (Dr Marie Abitbol, Dr Laurent Tiret) and the laboratory of Neurobiology (Dr Stephane Blot) from the Alfort School of Veterinary Medicine (ENVA), as well as the CNRS-University and ANTAGENE.

Pilot studies achieved during the development of the test revealed a high frequency of carrier dogs in the French population of American Staffordshire Terriers (30%). In addition, collaboration with Dr Natasha Olby (North Carolina State University, Raleigh) confirmed that dogs in the United States carry the same disease causing mutation as the one identified in the French dogs.

This new DNA test is a revolution for breeders and owners of Amstaffs. Thanks to a simple non-invasive cheek swab (cytobrush), a veterinarian can provide cell samples that can be analysed by ANTAGENE to identify affected Amstaffs before the first clinical signs as well as detecting carriers.

This allows breeders to exclude matings at risk (carrier x carrier producing affected dogs) and transmission of the disease-causing copy of the gene. Identification of carriers as well as affected AmStaffs is important to avoid the dissemination of the genetic defect in the breed.

The test is patented world-wide by INRA and ENVA. ANTAGENE has an exclusive international license to provide this test.

Recommendations 

According to the mode of inheritance by which Cerebellar Ataxia manifests in the American Staffordshire Terrier, breeders who use this test to their advantage can ensure that no puppy sold in the future will ever develop this disease. At the same time we hope introducing mandatory testing will encourage breeders to not only test their breeding stock but also breed away from this disease so that it no longer exists within our gene pool and to avoid the type of matings that may pose a risk of producing affected puppies.

We do not recommend culling any carriers and affected dogs from the gene pool at this stage as this will destroy an already very limited gene pool, if these dogs are bred to clear dogs then none of the offspring will ever become affected as offspring require one copy of the gene for this disease from each parent. So by breeding a Carrier or Affected to a Clear you will end up with carriers or clears in the litter but no affected.

There is also an issue of this test being relatively new, so we also realise that many people may have frozen semen from deceased dogs or untested dogs which was purchased prior to the test being available – We believe these people should be allowed to use this semen in due course provided this semen is being bred to a Clear female.

We have the worked out following break-down of possibilities for breeding practices and possible outcomes, which we recommend for implementation:

I have also attached a document from ANTAGENE with contact details & further information about the test now available for your reference.

Please note we have advised all other state currently affiliated breed clubs (ASTC of VIC, ASTC of WA and ASTC of QLD) of our submission to you and all clubs will be forwarding you their own set of recommendations in response to our submission in due course.