One dog's fight against cancer...
One in four dogs will get cancer in their lifetime. According to Petscreen, a company aimed at detecting and treating cancer, canine lymphoma is one of the most prolific cancers in the dog population. Breeds thought to be at high risk include boxers, rottweilers, german shepherds, retrievers and spaniels. At last year’s Crufts, PetScreen teamed up with the Morris Animal Foundation (MAF) to launch a global cancer awareness campaign. MAF is a US-based charitable, non-profit organisation funding cancer research. Established in 1948 it is aiming to eradicate canine cancer in the next 10 to 20 years with a $30million effort. It believes this could also help produce breakthroughs in the prevention and treatment of human cancers, particularly those in children. The funding will go towards clinical trials to test new therapies, prevention studies relating to genetics and the canine genome, and funding for a tumour tissue bank. Some of the work will be carried out in conjunction with the world’s largest animal cancer centre at Colorado State University. Lisa Soar has experienced first-hand the importance of canine cancer treatment and research after her four-year-old bitch Corrie was diagnosed with lymphoma in 2006. Here she tells Corrie’s story…
After an interminable pause the vet said: “It’s cancer.” Those two words which no-one ever wants to hear had just crashed into our world. My four-year-old Paul Tomkins-bred bitch Fynydd Corrie, out of Peg by Dolwen Mac, had been diagnosed with lymphoma. She hadn’t been ‘right’ for a couple of weeks. She’d been doing preying stretches, had diarrhoea and seemed lethargic. Troubling signs for a dog who was typically hyperactive, constantly on the go and always thinking. After a visit to the vet a mass in her gut was detected. During the subsequent operation a section of her intestine was removed, which appeared ‘telescoped’. This caused some confusion in the practice as it usually occurs in puppies, but the operation had gone well and it was hoped the problem had been solved. I was asked if I wanted a biopsy on part of the removed tissue - ‘just in case’. Having spent around £600 on the op, what harm was it going to do? Corrie recovered quickly from the operation and seemed to be back to her usual self when I took her for the check-up. It was then that I asked if the test results had returned. ‘I’ll just check’, said the vet breezily. I don’t think any of us had expected what the results would show. The prognosis: GRAVE, blinking at me on the computer screen didn't help my feeling of helplessness. A few days later I met the practice's vet who treats cancer patients, and who I would see many times in the coming months. We were given four options and I would need to decide quickly. Do nothing and Corrie would be dead in a couple of weeks. The next two options combined oral drugs and IV chemotherapy, but neither gave great chances of remission or short-term survival. The final alternative was a treatment plan - known as a protocol - involving an intensive course of chemotherapy at an estimated cost of £2,500. It gave an 80% chance of remission and a more than 50% chance of survival at one year after the start of treatment. For me, it came down to the first option of doing nothing or going the whole distance. The other two options seemed like token gestures. If we did nothing at least it would all be over pretty quickly for everyone concerned, but if there was a chance Corrie could still have some quality of life for a while longer then I was going to take it. The money was a huge issue and I ended up spending a lot more than the estimated cost. Some months most, if not all, of my wages would go straight to the veterinary practice. The vet discussed potential side effects and the fact that some dogs don’t cope with the length of time spent in the surgery, how the chemo is administered and some just don’t respond well to the drugs. Patients undergoing chemotherapy must do so because their team of carers, the veterinary surgeon, the oncologist and the owner, all feel the treatment is improving quality of life at all times. The aim of canine chemotherapy is to promote a good quality of life first and life expectancy second, something I was finding difficult to grasp - I just wanted to save her. There are many multidrug protocols. One is known as the CHOP protocol. It combines Cyclophosphamide, Vincristine (Oncovin) and Prednisolone, plus a drug called doxorubicin (Hydroxydaunorubicin). The COP protocol, which doesn’t use doxorubicin, has a reduced chance of inducing unwanted side effects but carries a reduced probability of inducing a complete remission. The average life expectancy on this treatment is approximately 6½ months. The CHOP protocols achieve complete remission in a higher percentage of cases and the average life expectancy is improved to approximately 11½ months, but the risk of unwanted side effects is greater. In order for us to embark on the protocol I had chosen, it was very important to get an early dose of Asparaginase, but being a particularly nasty drug my practice in Pembrokeshire didn’t stock it. We were referred to Vale Vets in Gloucester, a specialist centre where they are licensed to administer it. While we were there they also carried out an ultrasound on Corrie’s intestines, which showed a diseased mass, but her other vital organs appeared clear. The drug definitely had an effect on Corrie. She was very quiet for a few days afterwards, and had diarrhoea, as we had been told to expect. The doses of Vincrisitne also affected her, and this became worse as the months went by and the drugs built up in her system. Alongside the IV chemo she was also given Prednisolone and Endoxana tablets. The prednisolone dose was reduced week by week. The Endoxana was interspersed with the other drugs and could make her vomit a day later. Like people undergoing chemotherapy, the treatment suppresses the dog’s immune system, making them much more susceptible to infections. Any infection needs to be detected early so antibiotics can be started immediately. Our biggest problem was that after the Vincristine IV (the main drug in the protocol) Corrie’s white blood cell count plummeted to dangerous levels. She was at a much greater risk of picking up infection and it also meant we had to wait longer between treatments to try to allow the cell count to recover to a normal level. Another knock-on effect was that we couldn’t take her out anywhere, or any of the other dogs, in case they picked up an infection and passed it on to her. In some cases there are no visible side-effects and the improvement in the dog’s condition outweighs the minor impact of the treatment. In the early days of treatment Corrie seemed to cope well. She lost all her whiskers soon after the first chemo. Later she lost most of her coat on her chest and tummy and began to feel the cold. This prompted me to buy her a coat - not one of those sparkly, diamond encrusted abominations adorning so-called celebrity pooches - but a medically approved fleece jumper designed for elderly or ill dogs. The care given to her by the vets, veterinary nurses and receptionists at the practice was second-to-none. She had always been wary of people before the treatment began, in spite of going everywhere with me from a young pup. I think the biscuit treats may have helped her become affectionate towards people, but these days she wants to stop and say hello to everyone she encounters. The nurses told me that during her IV treatments she would sit on the table, holding her paw up, waiting for her leg to be shaved and the IV to begin. When we reached the end of the protocol in February 2007 we returned to Vale for another ultrasound and heart scan (chemo can damage the heart). Her heart and internal organs appeared fit and healthy and the intestine had improved from the first scan. Corrie is now in remission and I know she is living on borrowed time, but I would do it all again. At the start of June she reached her seventh birthday and is still looking well. Later in the summer she is due another blood test to check for any changes and we will take things from there. I would be lying if I said that as the protocol went on I didn’t question my decision to put her through such an intensive therapy. It was a stressful and emotional time of uncertainty and financial hardship. To an extent I had put my life on hold, and our world revolved around the next session at the vets and closely monitoring Corrie’s progress and side-effects. I wasn’t the only one who was making sacrifices. Mum had supported me all along, but because of the infection risks she had given up trialling her dogs too. I had had high hopes for the 2006 trialling season and now I will never know what our partnership may have achieved, but at least she is here and still enjoying life.
Making the decisionOutwardly Corrie was an extremely fit and healthy dog. I had never dreamed she would be diagnosed with cancer, and certainly not at the age of four. Making the decision to try the chemo was very tough, but Corrie had never been ‘just a trials dog’ to me. There were always so many questions which couldn’t be answered. The battle of drugs versus cancer was out of sight and out of my control. It was difficult to measure any sort of success, other than that Corrie was still alive. I wanted to know how the drugs were working, were they beating the cancer, if she was alive this week would she be alive next week? Thankfully, we got to the end of the protocol and she is still here. I don’t know what the future holds, but who does? At the time of Corrie’s diagnosis another couple were facing the same tough choices. Linda and Nick Harris discovered their black Labrador bitch had lymphoma in March 2006, when she was still three months short of her second birthday. They were told she would be lucky to last a month. Taking the vet’s advice, they also began an aggressive course of chemo which lasted for nine months. Following this she was pronounced clear and has had a good life since. The couple said: ‘We were very dubious about putting her through the treatment, having seen humans suffer with it, but in the end it wasn’t too bad. ‘We found she had a couple of off days after each of the IV treatments, but it did not appear too bad, and other than those three or four days a month, she was full of life. ‘There is no doubt in our minds that the treatment was a great success.’
What is lymphoma?Cancer is an unregulated growth of cells. The lymph system is the body’s ‘other’ circulatory system, circulating white blood cells and lymphocytes. These are specialised cells involved in immune function. In healthy dogs, these cells are made in the bone marrow, have a lifespan of around 30 days, and then die and are reabsorbed into the body or pass through the waste channels. In lymphoma, the regulation of production is lost and these cells proliferate in large numbers, or they lose their programmed life cycle and continue to live on, overwhelming the other blood cells. High white blood cell count and swollen lymph glands are the characteristic signs of lymphoma, followed by lethargy, loss of appetite and leading to death unless treated. Other types of lymphoma include alimentary, mediastinal, cutaneous and extranodal. During alimentary lymphoma, which involves the stomach and the intestines, the dog will usually experience vomiting and diarraeohea, weight loss and lethargy. Mediastinal lymphoma causes a growth of cancer in the front part of the chest leading to fluid in the chest and difficulty breathing. Cutaneous lymphoma affects the skin and is uncommon. Extranodal lymphoma is a combination of other potential sites in the body that can be affected with this form of cancer. These include the eyes, the central nervous system (the brain and the spinal cord), bones, heart, kidneys, bladder and the nasal cavity. Relapse
|
