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Negative implications of DNA Testing for Progressive Retinal Atrophy
I have been reflecting recently on the effects of DNA testing for Progressive Retinal Atrophy on Australian Cattle Dogs and, specifically, some ACD breeders' desire to eliminate this 'defect' by embarking upon an elevated level of selection in their breeding programmes. Now they march forward armed with their precious DNA test results, no longer considering for breeding purposes any dog that is not a Pattern A (clear). Surely breeders must have the sense to realise that a breed with a small gene pool (here, not worldwide) is not helped by this type of selection and with it the further elimination of genetic diversity? You cannot take a knife to those 'defective' or unwanted genes and remove them like a benign tumour - there are consequences - many other genes that reside on the same chromosomes will be eliminated right along with the defects, and the end result in doing this may not be realised until it is too late. For example due to genetic bottlenecking on a small number of Pattern A animals there is the distinct possibility of a reduction in the fitness indicators we should all we aware of, for example fertility (percentage of successful matings), fecundity (average litter size compared to the norm for the breed), birth weights, puppy viability, survival to adulthood and longevity. To see a reduction in these important features is much worse than 'throwing the baby out with the bathwater', this is throwing out the whole family along with the bathroom suite!
Of course I want to breed away from the defective allele but in cases where dogs are of overall excellent quality it, surely, must be a loss to the breed as a whole if they are to be rejected as potential studs or broods simply as a result of their carrier/affected status? Breeding stock should always be evaluated for a range of balanced characteristics - health, vitality, temperament, working ability, intelligence, structure and type. All of these should be considered in an evaluation of the TOTAL dog. Would anyone argue the point that an all-round balanced dog is a much better hope for the future than a highly selected, over-bred dog turning out offspring, or that was produced itself in the first place, simply because of an unaffected PRA status?
This condition is a simple autosomal recessive that is easily worked around whilst continuing to incorporate Pattern As, Bs and Cs into the breeding programme. It is my opinion that as breeders work towards minimising the number of carrier and affected animals the overall problem for the breed will diminish accordingly, but the key word is 'minimising' not going for all out eradication over a short period by radical culling through the rigorous selection some appear to be embarking upon.
Rocky
Am Ch Silveraurora's PW Tom Thumb HIC is a dog with a lot of potential. He achieved his herding certificate whilst still in America and has passed on his abilities to those of his offspring fortunate enough to have had the opportunity to work stock. Whilst he has done us proud in both the show ring and as a stud we knew that he had so much more to offer that we were not in a position to provide an outlet for. So, for this reason, and also to help the gene pool in Ireland, Rocky has gone to stay for the foreseeable future with Darryl Moffat. Rocky remains in our ownership and if anyone in Ireland is interested in using him they can contact us in the first instance on normaacds@btinternet.com
Teeth
Recently I have been thinking about how the decline in the original purpose of the Australian Cattle Dog has induced the breed to change. This has, of course, been influenced to a large extent by trends set by show breeders and judges some of whom no longer appear to even consider the breed with an eye to function. In this breed one area that the functionality of the dog hinges on is, of course, its teeth.
Maybe some breeders don't worry about the occasional missing premolar but personally I feel this is a slippery slope. If a missing P1 is not considered to be a big deal what about the other premolars or the maxilliaries - where does it stop? When would it be considered to have gone beyond the pale? Would this be when the width of the jaw changes, when heads have become narrower or dogs are commonly found to be missing teeth all the way through from P1 to P4?
I certainly don't have all the answers, just the questions! One of which is whether missing teeth are down to genes, environment, diet or even some sort of maternal low grade infection or parasite? Another is whether missing teeth could be in some way related to the shortened muzzles seen in some dogs today where there might not even be the room for the appropriate number of teeth? This fad for shortened muzzles results in shortness of breath after being worked or generally exercised, so is limiting the ability for endurance which is the benchmark of the working ACD. A short muzzle is NOT a 'strong' muzzle, the biting strength comes from the muscling attached to the skull and under the eye, not the muzzle itself. Look at some of the heads that are out there- do they have the correct skull to muzzle proportions of 3:2? These dogs with short muzzles very often also have domed skulls which give an incorrect prominent stop (ACDs should have a slight break between the eyes, a prominent stop, or a wedge of cheese with no break at all, is incorrect) but that is another story!
cosmetic traits that breeders are preoccupied with and anything other than a full mouth should be viewed with appropriate seriousness by judges.
I understand about and exclude any dog from the above musings that have lost teeth in an accident, are lost or worn through old age or have had necessary extractions .
Working Instinct
It seems that Rocky (Am Ch Silveraurora's PW Tom Thumb HIC) has passed on more than just his good looks to his children! We were delighted to hear that Rocky's daughter, Yarraman Wannabe A Wallaby (Taz), is making a very good job of working sheep. Suzanne Nevada, Rocky's breeder, says that Taz's grandmother, Am Ch Bull Mtns Red E To Rock HIC also has a talent in this arena.
General Comment
We are concerned that all-rounder judges do not seem to understand the movement required in Australian Cattle Dogs. When moving at speed and viewed from the front ACDs' legs converge towards the centre line of balance. This also means that ACDs may look close behind as the rear must, of course, follow the front!
An excellent website for seeing movement, both good and bad (whilst remembering that this breed has a tendency to more convergence to the midline than the APBT) is at http://www.apbtconformation.com/movement.htm
Contact Norma Digby on 01948 841302 (Shropshire, England, UK) |
