Cancer as we know is the biggest killers of dogs worldwide, it does not matter if they are pedigree or cross bred. There are so many types of cancer affecting dogs, some can be treated, and the dog will continue to lead a happy life for some time after treatment, others are more difficult to treat.
As I have said on many occasions that one of the very few positive things to have come out of the pandemic is the wider use of the Internet, so that people can communicate with each other without having to travel miles, with the price of fuel and the traffic nowadays this is a definite plus. On Wednesday evening 7th August I was able to sit at home and watch a KC webinar given by a Dr from Davies Referrals which is one of the largest referral centres in Europe, this was on Hemangiosarcoma’s which are malignant tumours found in the cells lining blood vessels, it accounts for about 5% of cases of cancer as blood vessels run through the whole body. More usually it is found in middle aged and older dogs and there are several breeds that are very prone to it, but it was pointed out that it can affect any dog, some studies show that it may affect males more than females, but it does not seem to matter whether they are castrated, spayed or entire. It can occur in the body cavity or on the skin, where it shows itself as small raised dark red or purple nodules, smooth coated breeds are especially susceptible, particularly those that like to sunbathe. The nodules can be surgically removed., so usually there is a full recovery. When it occurs internally affecting the heart, lungs, or spleen it is difficult to detect and usually proves fatal if not treated quickly and even then, the dog may only live months after treatment.
The dog can be well one day and then owners notice it start to become lethargic, perhaps with diarrhoea a fever and pale gums. An urgent vet visit is necessary where the history of the dog will be taken along with blood tests and a scan and possibly a biopsy. Although the tumours can be found on the internal organs, they usually start in the bone marrow then travel throughout body and cause blood-filled tumours on the internal organs these can rupture when they are full of blood and causes sudden death. Although as it was said earlier any dog can suffer from hemangiosarcoma there is a definite genetic link in some breeds.
What I found very interesting was that breeds in one country will have a slightly different genetic make up for the same breed in another country. One of the questions asked from an owner of one of the breeds most often affected, was if it was in their line should they stop breeding from that line, the answer was that in that breed it would be very difficult to find a clear line, so no. There is wide ranging research going on by the University of Minnesota and the University of Nottingham, and it would seem that neither environment or diet plays a part in to whether or not the dog suffers from the disease. Treatment depends on the extent and size of the tumours, cases where the cancer is localised to the spleen, and it has not ruptured surgical removal can be an option but even with Chemotherapy afterwards the survival time tends to be only a few months.
Dogs do not suffer the same side effects that humas do with Chemotherapy, although owners are usually given anti sickness for the dog just in case it suffers from sickness after treatment. There is also Metronomic therapy in which the anti-cancer drugs are given at a lower dose. NSAID drugs can also be used but these tend to cause the dog to have cystitis. Thalidomide is also used in various parts of the world but not in Europe and the UK as it is too expensive. Work is being done to find immunotherapy, but this is not commercially available at the moment, this works by using the dogs immunome system to fight the cancer. If the pericardial sac of the heart is involved this can cause heart failure an operation is not usually possible, but fluid can be drawn from the sac. It was stressed that an operation may not be an option in all cases, it must be what is right for the dog with its quality of life being the most important thing. One test that was talked about that might help with diagnosis in the future was Liquid Biopsy Test, this test refers to the testing of blood, urine and other bodily fluids to help identify the disease. This looks for DNA fragments that are released by the tumours and proteins associated with the various tumours, it is meant to be used alongside conventional testing not replace it and is widely used for cancer screening in humans .
Many years ago, my second Buhund had a splenic tumour removed, he did not have any treatment afterwards and it was hoped he would make a full recovery, to start with he seemed to be recovering well, but then he started to get very aggressive which was totally out of character as he was a very sweet natured dog. I thought perhaps it was him responding to the shock of the operation but now having listened to the webinar I think he probably had cancer elsewhere as well. Sadly I said good bye to him as he was a very unhappy dog, I often wonder if I should have put his through the operation, but he would have died if he hadn’t and you always do what you think is best for them at the time.
Margaret Deuchar margaretdeuchar@gmail.com