By Dr. S.E. Brownlie
There has been a modest upturn in demand for heart testing in 2007 and organised sessions were long days. I am very grateful to Rebecca Peek, Jo Braine, Dagmar Kenis-Pordham and Roger and Debbie Tebbutt for helping to organise these sessions and for their hospitality.
In January at the Irish Wolfhound Society Open Show 17 hounds were tested, mainly with good results.
Two sessions were held in April. Seventeen dogs were examined at the Irish Wolfhound Club Ch show on 22/4/07 and 10 on the following day at Hollyhenge, 11 dogs and 16 bitches in all. There were seven with atrial fibrillation (mostly previously diagnosed and coming for check-ups), 10 in the equivocal category and the rest were normal.
In September again two sessions were held, one at Peters Farm in Sussex where 16 hounds were tested, 3 dogs and 13 bitches, and at the Irish Wolfhound Society Ch show, at which 21 hounds were examined, 8 dogs and 13 bitches. There were 9 cases of AF, mostly previously diagnosed, with 8 in the equivocal category. One had had abnormalities on a previous examination but had none this time, which is always good news. However one bitch had ultrasonographic evidence of DCM with a normal ECG, which was a big surprise. This happens only occasionally but is proof that ultrasound is essential to the examination.
In November the last session of the year was held in Anglesey. Again 21 hounds were examined, although three were youngsters for auscultation only. There were 6 dogs and 15 bitches altogether and 4 hounds had AF. This session also highlighted another cardiac abnormality which I had not recognised previously in wolfhounds ie aortic regurgitation. This is not associated with DCM and I am uncertain of its significance but I shall watch for it in future.
The advantage of the non-show testing sessions is that in a quieter environment older dogs can be tested with less stress, and it is hoped that regional testing sessions may allow examination of hounds which would normally be left at home. It may be that the results will appear to be worse than we have previously experienced but we know that heart disease is to be expected more in older dogs. It must be remembered that our overall prevalence of atrial fibrillation of around 10% in UK, (considerably less than has been reported in other countries) is obtained from data mainly from shows where there are many more young dogs than older ones.
There has been a study reported in USA suggesting that DCM might be an X- linked disease in wolfhounds ie affecting only males with carrier females. In my opinion this is unlikely - we do see a higher percentage of males than females with AF, but I believe this may be because females tend to develop it later and our heart-tested population consists mainly of young dogs.
Next year?
We now have several other veterinary cardiologists on board with regional
testing and I understand that the first of these sessions is to be held in
Northern Ireland in February, which is very exciting.
Heart testing is now part of the breeders' Code of Ethics and the reassurance of testing is also important to pet owners.
Please support testing sessions near you, because the cost will be tiny compared with the cost of a normal referral to a cardiologist. If the uptake is low they will not be repeated!
Where are we now?
The Heart Research Project began in 1986. I sense that there is frustration
among breeders and owners that we do not seem to be much further forward than
we were then, but I need you all to see it from my point of view. I have spent
the last few days looking through my data, trying to decide how much it has
helped my understanding of wolfhound heart disease and how we can best use it
for the good of the breed. There may be environmental contributing factors but
basically I think everyone involved with wolfhounds now agrees that DCM is a
genetic disease, though it has different manifestations which are often
confusing.
In some breeds with heart disease, the names of "clear" animals are published, so that breeders can see which lines are producing healthy stock. In the UK wolfhound study, we have never breached owner confidentiality, although I am sure there have been rumours at various times to the contrary. Although essential, this has been very frustrating to me - I am sitting on a goldmine of information, which may never see the light of day because some people may be upset if it were published. Most of the dogs are now long dead, and in some cases their owners too. I need to know what you wish me to do with this data!
There has been much discussion recently about longevity in wolfhounds and how much the common wolfhound diseases such as DCM, osteosarcoma etc influence life expectancy. It appears that lifespan improved in the 1950s and 1960s with the introduction of vaccination and antibiotics, but even with medical advances, average lifespan has now decreased. It may be that there are "longevity genes" in addition to "disease genes". If so, trying to breed away from these major problems may not help to prolong life greatly. However there is no doubt that heart disease claims the lives of many wolfhounds at between 4 and 7 years of age, and some even younger which is devastating for owners. I have serious issues with close in-breeding in a breed which has so many problems. The dog you are in-breeding to may be a wonderful show specimen but it might turn out to have heart disease or some other dire problem, especially if it has not been tested. By the time that dog is ill, it may be too late to undo the problems that will inevitably result.
Of course dogs have to die of something and if it affected them all at 12 years of age it would not be a problem! In the Cavalier King Charles spaniel recent research has suggested that the older the parents at the onset of heart problems, the older the progeny will develop it. This has given CKCS breeders the aim of using the oldest disease-free stock possible in the hope of gradually increasing the age of onset until it is no longer a problem in the breed. In my experience that is not the case in wolfhounds unfortunately and even if a wolfhound develops DCM at 11 years, there is a good chance that its progeny will develop it younger. This means that any case of DCM, even in a very old dog, should not be dismissed as "old age" and considered irrelevant. In USA there are efforts under way to conduct "whole of life" studies in families - if we had done this when the project started 21 years ago, we would already have the answers! What we have instead is large amounts of random data, mostly from young dogs with no follow-up, a lot of work for very little gain. Of course what we have is still interesting, but what we need is the "oldies" with good hearts, if nothing else to provide the DNA for future research - once these dogs are dead it will be too late!