Testing available for Whippets: Longhaired – August 29, 2006
Recently, several Whippets of the Longhaired Variety (LHW) in
were DNA tested by OptiGen. This testing was prompted by The Longhaired Whippet Association as the result of 3 optic colobomas having been recorded over a period of 7 years of CERF testing.
OptiGen was able to diagnose those 3 dogs with optic nerve coloboma and other characteristics of the eye disease known as “choroidal hypoplasia” (CEA/CH). This condition also occurs in breeds such as most Collie Varieties, Lancashire Heelers and Australian Shepherds. Earlier this year OptiGen also proved it occurs in the Nova Scotia Duck Tolling Retriever.
The background information on disease characteristics and inheritance found with regards to CEA/CH applies in general to LHWs. However, the purebred population of Whippets exhibiting long hair is small, with only three known affecteds to date. At this time due to only a small fraction of the variety being tested, we cannot estimate the frequency of carriers among these dogs.
Two additional LHWs of unknown pedigree or separate lineage were also identified as affected. These affected dogs have the cardinal signs of CEA/CH as recognized by a veterinary ophthalmologist, which lead to their being tested by OptiGen. These dogs also are genetically affected according to the OptiGen test, that is, they each have two copies of the recessive mutation which together result in CEA/CH.
CEA/CH is caused by a recessive mutation. Dogs that inherit a mutation from each parent are genetically affected, even if symptoms are not recognized. Each parent and all offspring of a genetically affected dog will be a carrier or even affected. Following that basic rule of recessive inheritance, owners can select which of their dogs should be tested. If no information is known about parents or offspring, a dog should be tested before breeding. In all situations, at least one parent of the breeding pair should be genetically normal for CEA/CH according to the OptiGen test. The test can then be obtained for litter-pick puppies in order to identify the carriers and plan the next generation accordingly. Be sure to go to the CEA/CH link and scroll to the table “Expected Results of Breeding Strategies for Inherited Recessive Diseases” for further information.
Through December 2006, OptiGen will CEA test any clinically affected Whippet or Whippet of the Longhaired Variety for free, if you have a veterinary ophthalmologist's written diagnosis of CEA/CH, with or without coloboma or detached retina. You need to mail or fax to OptiGen a copy of the diagnostic report and a 4-5 generation pedigree for pre-approval before submitting a sample.
OptiGen is pleased to have worked with The Longhaired Whippet Association to uncover and prevent this hereditary disease in future Whippets of the Longhaired Variety.