Unexplained weight loss is a worrying sign in pets
Dandy, a fourteen year old Lurcher, had started to slow up, not enjoying his walks as usual. When I'd examined him, I'd found that his hips were painful: he was suffering from arthritis. X-ray pictures showed that both hip joints had the roughened, ragged edges that's diagnostic of the problem. I had done a blood test to confirm that his internal metabolism was functioning normally, including his liver and kidneys, and then I had put him onto the standard treatment for arthritis. This involves a patchwork of medications: pain relief and nutritional supplements to allow his hips to function as smoothly and painlessly as possible.
Dandy responded well to this regime at first, getting his energy back, and enjoying walks again.
Six months later, he started to slow up again, but this time it was different. As well as losing enthusiasm for walks, he also stopped being so interested in his dinner. This had never been a problem for him before: he had always had a hearty appetite. He had no other signs of illness: no upset stomach, no cough, nothing to give any clue as to why he didn't want to eat as much as normal.
At first , John, his owner, tried to work around the poor appetite by offering tastier food: he changed from the standard dried kibble, instead offering moist food in tins or sachets. The initial effect was positive: Dandy was enthusiastic when his dinner bowl was put down, and he started into his food with gusto. But he still didn't finish his meals, and when John brought him in to be weighed, he had dropped nearly 10% of his body weight compared to six months previously.
Unexplained weight loss in an older animal is always worrying: while there's a long list of possible causes, the threat of cancer is the one that vets worry about the most. There are many possible types of cancer, and some are easy to diagnosis. As an example, sometimes you can feel a solid mass, like a lump, when you feel a dog's abdomen. Other cancers are more difficult to diagnose, and owners can be faced with difficult choices. How far do you go with investigations? It takes time and money to carry out thoroughly detailed tests. Dandy had been such a wonderful pet that John wanted to give him the same level of investigation and treatment that a human member of his family would be given.
So we started a comprehensive diagnostic work up. First, I carried out a careful physical examination. Sometimes small clues can be found - such as slightly enlarged lymph nodes - that point towards the location of a tumour. In Dandy's case there was nothing: his body appeared healthy, but thin.
The second stage was to carry out screening laboratory tests on his blood and urine, measuring a range of chemicals and enzymes, searching for any elevated or depressed levels. Everything was completely normal: there were no clues. This was turning out the be a tricky case.
The third phase involved diagnostic imaging. X-ray pictures were taken of his entire body, from his head right down to his tail, again looking for any areas of abnormality. And again, everything was normal.
We also carried out an ultrasound scan of his chest and abdomen, and this was where we finally discovered something strange. The scan showed that there was a small, hazel-nut sized area of thickening in the wall of his intestine, close to the exit of his stomach.
Theoretically, this small nugget of abnormal tissue could have been benign: for example, if a dog suffered physical damage to the lining of the intestine (perhaps by eating something sharp), scar tissue could develop with a similar appearance to this. However, if that was the case, it would be unlikely that Dandy would have lost his appetite so seriously, and nor would he have lost so much weight.
John wanted to be absolutely certain about the diagnosis, so we moved to the next stage: a biopsy, harvesting a small section of tissue from the abnormal area. This is often easy to do with ultrasound.
Dandy was anaesthetised, to make sure that he stayed still, and to protect him from any discomfort. The ultrasound probe was then placed on the side of his abdomen, and a long biopsy needle was inserted through his abdominal wall. The tip of the needle could be seen using the ultrasound, and the operator was able to make sure that she took a sample at precisely the right place.
The sample was sent to the laboratory. A week later, the result came back, and sadly the news was bad. This was an inoperable type of cancer that could not be treated.
John was satisfied that he had now done enough for his friend: he had the diagnosis he had been looking for. It was now just a case of keeping Dandy comfortable for as long as possible. It's now a month later: Dandy is even thinner than before, but he's still in good form. John brings him in every two weeks for a weigh in and a check up, so we are monitoring him carefully.,This will be Dandy's last summer, and John is making sure that he enjoys it.
When the time is right to let Dandy go, John will at least be able to reassure himself that nobody, anywhere in the world, could have done more for this lovely, gentle dog.