Lymphosarcoma (LSA) in a dog
Chloe, a 7 year old mixed breed dog, was presented to us after being slightly off colour. We noticed all of her lymph nodes were swollen. These are the "glands" that people can feel under their neck when they have a sore throat. Lymph nodes react to infections and are the body's first line of defense. They swell up when "fighting a battle".
Lymph nodes are found throughout the body: under the skin, in the chest and in the abdomen. The tonsils form part of this network and will swell up if fighting a throat or mouth infection. They are all part of the lymphatic system responsible for keeping the body protected against infections.
Unfortunately, in humans and cats and dogs, we see a cancer of the lymph nodes called Lymphosarcoma (LSA). In cats, it is usually caused by a virus called Feline Leukemia Virus (FeLV) which is preventable using a vaccine. In dogs and humans, the cause of LSA is not known.
Sometimes, LSA does not just cause swelling of the lymph nodes. It can appear as a solid tumour of a body organ (e.g. kidneys, intestines, liver) and in some cases it involves the bone marrow causing leukemia.
We removed an entire lymph node from Chloe's hindleg and sent it to a pathology lab for analysis. This was to rule out other possibilities e.g. response to an overwhelming infection or irritable skin problem. When we opened Chloe's mouth to place an anaesthetic tube in, the tonsils were so swollen we had difficulty passing the tube into the windpipe (trachea).
A diagnosis of LSA was made by the lab. The owners did not wish to try chemotherapy and she was euthanised a few days later.
Chemotherapy using combinations of different drugs can be quite successful in getting rapid reduction in the size of the body's lymph nodes. However, the trick is in keeping the LSA from re-occurring.
In veterinary medicine, we don't use the very high doses of chemotherapy used in humans so serious side effects like hair loss are not so common. None the less, regular blood tests and monitoring for other side effects is essential.
Because chemotherapy drugs can cause serious illness in people who accidentally come in contact with them (e.g. needle stick injury, squirted some in to the eye) all waste material has to go into a special waste unit for proper disposal.
All staff involved in handling the chemotherapy drugs have to gown up, double glove, wear masks and wear safety eye goggles.
The chemotherapy drugs can be very expensive.
We offer chemotherapy at BHVG after sending all case material to Tony and Angela Moore (Vet Oncology) who tailor make chemotherapy protocols fro each individual case based on the grade and severity.
Treatment for LSA is very involved, expensive and requires total commitment from the owner. Life expectancy can be increased by several months and some cases go onto full remission.
Feline Leukemia Virus (FeLV)