The inheritance of coat colour in the Australian Stumpy Tail Cattle Dog (and in his long-tailed cousin, the Australian Cattle Dog) is complex. The inheritance of colour in both breeds is described by Dr Helen Hewson-Fruend and Noreen Clark at www.adcb.au.com. Miscolour (coat colour that is unacceptable in terms of the Breed Standard) occurs in both breeds. In the ASTCD the most common miscolours appear to be: tan points, chocolate, cream, and white.
Miscoloured ASTCDs should not, of course be used for breeding. However, it is evident that many excellent ASTCDs carry miscolour. The ASTCD breed population is small and miscolour carriers should not be excluded from breeding if they are otherwise excellent.
Coat colour genes are not breed specific. The ‘b’ and ‘e’ genes, for example, are associated with chocolate and cream miscolour in the ASTCD, and these genes are also found in the Labrador Retriever. VetGen (USA) has developed a DNA test for Labradors that can identify carriers of chocolate and/or cream. VetGen is now accepting ASTCDs for colour testing. Not many ASTCDs have been colour tested but combined with colour testing in the ACD breed the test for genotyping for colour has now been released. So far, however, all test results have been consistent with expectations and Noreen Clark, who is evaluating all results in association with VetGen (www.vetgen.com), is confident that the Labrador tests are valid for ASTCDs & ACD. This has proven to be correct.
At Ambajaye, colour testing is being used to reduce the incidence of chocolate pups, and of cream/apricot pups. Photos of these colours are featured below. Some look like pale red ASTCDs, except for their liver-coloured nose leather and pale toenails. Their liver noses may be so dark as to appear almost black.
