The above plea was made by Dr Serena Brownlie at the recent Irish Wolfhound Health Group Seminar, held at Balsall Common, near Coventry on Saturday 23rd November 2013. During her very informative talk in the afternoon about the IW heart testing scheme, which is now run in conjunction with the IWHG, Serena explained that her biggest wish was that she could heart test Hounds every year throughout their entire life as this would bring about the most useful data for the whole research study. Out of the 1897 Wolfhounds heart tested under the scheme, only 815 dogs have been examined more than once. The study into IW heart disease began back in 1986 and at that point very little was known about heart disease in dogs in general and certainly no studies had been carried out into individual breeds. Even the Royal Veterinary College did not possess a small animal ultrasound machine and they thought Serena was mad to suggest such a study! Fortunately things have come a long way since those early days and now Wolfhounds are routinely heart tested at regional sessions up and down the country and in Ireland (as well as those kennels that have their own private heart testing breeder days), thanks to the organisation and valuable time and effort donated by the members of the IWHG, particularly Rebecca Peek, Sue Bevis, Anne Wilson who deal with the day-to-day arrangements. Also Serena Brownlie has been joined by other colleagues to assist with not only the testing, but also DNA gathering and data analysis and research, these include Dr Angela Bodey, Prof Malcolm Cobb and Siobhan Simpson (a PhD student conducting research at Nottingham University in conjunction with Malcolm and Serena).
What happens at a heart testing session and why is it so important?
Heart testing a Wolfhound is now a straight forward and non-invasive affair and doesn’t take long for the cardiologist to complete. The first stage is to listen to the dog’s heart with a stethoscope, checking the heart rate and also listening for any abnormalities. Then echocardiography measurements are taken using an ultrasound machine (using 2D & M mode, Doppler) to show the size and shape of the heart and the blood flow through it and finally an ECG (Electrocardiogram) is taken to record the dog’s heart rhythm. All of these results from the 3 stages of the examination are recorded onto the heart testing form (a form also used and developed by the Veterinary Cardiovascular Society) and are later added onto the database which Serena set up many years ago. Heart testing Irish Wolfhounds from 18 months of age onwards is vital for many reasons as it is one of the 2 biggest health issues and potential killers in our breed, but really it is key for the ongoing health of the dog concerned. If a Wolfhound is unfortunate enough to develop any kind of heart problem (there are many variants to heart disease) then early detection of any anomalies is essential so that the dog can be treated and realise its maximum life expectancy and veterinary intervention at an early stage can make a massive difference to the outcome.
If we find my Wolfhound has a heart problem what should I do?
It is not uncommon for dogs to be routinely heart tested and the cardiologist to come across an ‘anomaly’ which results in the heart test form being completed as the dog falling into the ‘Equivocal’ or ‘Abnormal’ categories (the other category on the form being ‘Normal’), but owners should not go into a state of panic at this point. The Equivocal category requires that the same dog be re-tested 6 months later to see if the anomaly is still present and still displaying the same signs. Often the anomaly picked up on the original heart test will have, to all intents and purposes, ‘disappeared’ and so the dog is passed as being ‘Normal’. On other occasions the anomaly will still be present and the cardiologist testing will advise the owner to consult their own vet regarding possible treatment or ongoing monitoring, but this will vary greatly depending upon the findings of the cardiologist and the signs displayed by the dog. The same is true for the ‘Abnormal’ category, where the cardiologist has found an issue that requires further investigation by the owner’s own vet. The discovery of an anomaly is NOT a death sentence, nor is it necessarily anything that will shorten that dog’s life, but intervention at this stage could well prolong the Wolfhound’s life. There is a huge difference between heart disease (with its spectrum of variants) and heart failure as many dogs can live relatively normal lives with many aspects of heart disease. Any dog that has gone into heart failure (whether they had shown up earlier signs of heart disease or not) displays common symptoms which are difficult to miss and usually include:
- Rapid and irregular heart sounds and a consistent heart rate of over 200 beats per minute typically a Wolfhound has a heart rate of between 60 and 200 beats per minute, with the average being 108, but after exercise or during periods of stress the heart rate can be high, but will settle once the dog has also settled)
- A pulse rate which is lower than their heart rate
- An intolerance to exercise – struggling on walks
- Weight and muscle loss
- Breathing difficulty
- Fluid in the abdomen
- Episodes of collapse (leading to sudden death)
What are the most worrying heart problems seen in Wolfhounds? Any dog that has diagnosed heart disease may display symptoms of any one of a number of anomalies and these include ECG abnormalities such as;
- Supraventricular Premature Contractions
- Ventricular Premature Contractions
- First Degree AV Block
- Left Anterior Fascicular Block
- Supraventricular Tachycardia
- Ventricular Tachycardia
- Right Bundle Branch Block
- Second Degree AV Block
However, the above abnormalities are not usually life threatening in their early stages and appear to affect only small percentages of the population of Wolfhounds heart tested, but some of these anomalies can go on to develop into a condition called Atrial Fibrilation (usually shortened to AF) and current data shows that AF affects around 15% of the dogs tested. AF is one of those conditions that can send owners into a total panic on diagnosis, so why should we be concerned about it? Well, although not all dogs with AF will go into heart failure the heart testing research does tell us that dogs that do die of heart failure all have AF. Atrial fibrillation affects the ability of the atria (top chambers of the heart) to contract and push blood into the ventricles (lower chambers of the heart) and the atria quiver due to the muscle cells, which normally control the electrical activity of the heart, becoming disorganised. The longer a dog has AF the more difficult it becomes to treat. Usually AF develops in older dogs with advanced heart disease and is more common in bigger breeds and is distinguished by a rapid heart rate and chaotic heart rhythm. From Serena’s data there have been 148 male Wolfhounds diagnosed with AF and 147 bitches, with 70 known cases of cardiac failure, but only 8 reported cases of sudden death. Again the database information shows that on average, males are diagnosed with AF at 53 months of age and bitches at 66 months of age, so continuing to heart test Wolfhounds every year of their life and not just up to the age of 3 or 4 is vital. From the point of diagnosis to the time of death/cardiac failure the average length of time was around 2 years – so dogs can still live for a certain length of time even with AF, but early detection is crucial. Irish Wolfhounds are more prone to develop AF because they are big animals and an early study showed that the condition was more common in the largest of the Wolfhounds, especially those with the biggest chest measurements. However, AF is not just a condition affected by sheer size as studies of other giant breeds do not show such a high prevalence and so there is strong evidence to suggest a genetic predisposition to the condition in our breed.
Dilated Cardiomyopathy (again usually abbreviated to DCM) is another condition that strikes fear into the heart of any dog owner and most certainly a giant breed owner and no article talking about heart testing could fail to mention it – it is a killer! Similar to AF, DCM is not just a condition confined to giant breeds, but is also another condition that shows a predisposition in Irish Wolfhounds, probably for very similar reasons to the breed’s predisposition for AF (large animals, deep-chested where the heart is working harder). The causes of DCM are unknown, but the symptoms are similar to AF and diagnosis is always made using an ultrasound scan (hence why the condition can be detected at a routine heart testing session).
DCM is characterized by an enlarged heart, with both the upper (atria) and lower (ventricles) chambers being affected, but with one side more severely affected than the other. The heart cannot then function properly and the enlargement of the lower chambers means that blood cannot be pumped properly into the lungs and the rest of the body deteriorates. As the ventricles fail to pump enough blood, the lungs start to fill with fluid until a point is reached where the heart becomes overloaded and the animal goes into congestive heart failure (CHF). Dogs diagnosed with DCM do not have a very good prognosis and usually only live for a further 6-24 months depending upon the degree of progression on diagnosis), but their symptoms can be eased with medication and dogs are made more comfortable.
What is being done about these heart problems and what can ‘we’ do to help?
We have come a long way since 1986 and Serena’s initial heart testing sessions and the work is ongoing and must be continued if our beloved Wolfhounds are to benefit from health advances and improvements in the future. The actual database is now at a stage where the data can begin to be analysed and at the IWHG Health Seminar this month the ‘Cardiology Panel’ explained that an initial figure of £8000 would fund a ‘first array’ of analysis and then pave the way for a larger analysis (costing a further £17,000 or slightly less), from which we hope to identify key features of heart disease in Irish Wolfhounds and that is why Bonaforte Kennel announced their heart research fundraising a few months ago (http://www.bonaforte.com/heart-reseach-donantions/).
The ultimate goal and ‘the dream’ is to identify the genome responsible for heart problems in our dogs and all of the studies so far point to this gene being autosomal dominant (this means that the gene can be inherited even if only one parent is affected and the other parent may not have the gene). This factor is even more critical for breeders of Wolfhounds as even if just one of the parents carries the gene (and they may not display and symptoms of heart disease at the time of mating) it will be passed onto the puppies and some of those puppies will go onto develop problems. Another complication is that the age of onset in the parents is not a guide to the age of onset in their offspring – so just because one of the parents does not develop heart problems until late in life, does not mean that its offspring will do the same, the offspring could show symptoms of heart disease much earlier. In addition, the parent/s may only develop a minor abnormality, but the offspring could develop something much more serious such as AF.
As owners we can all help the research and the future health of the breed by continuing to heart test our Wolfhounds annually, until they die, no matter what medical conditions they may be diagnosed with during their lifetime. Without our help the research would not have come this far and also will not be meaningful in the future, so we must continue to heart test our dogs and also encourage others to do the same. One of the saddest things I hear from owners of Wolfhounds when asked if they want to come along to a heart testing session is: “well I’m not breeding with the dog and it is just a pet so I don’t need to heart test”. Not only is this a rather narrow minded attitude to a dog whose breed has a predisposition to heart conditions, but potentially that owner could be putting their dog at risk as any anomalies would be detected much earlier if the dog is tested on a yearly basis. So we conclude this article in the same way as we started it: