Tumours of the spleen are not uncommon in older dogs. The spleen is an organ near the stomach that filters out old red blood cells from the blood and also aids the immune system. About two-thirds of tumours found on spleens are malignant (spreading) and most of the malignant tumours are the kind that is called hemangiosarcoma. German Shepherds are the most susceptible breed to this kind of spleen tumour. Spleens can also become enlarged due to bleeding in the spleen or from fighting an infection and this is often confused with a spleen tumour. Enlarged spleens are more common than spleen tumours.
Symptoms of a spleen tumour can include distension of the stomach, weakness, fever, diarrhoea, increased urination, weight loss and loss of appetite. If the tumour ruptures, which is common with hemangiosarcoma, the dog will be severely weakened due to loss of blood and the gums will become pale. This requires emergency surgery to remove the spleen and tumour and to stop the bleeding.
If a veterinarian suspects a spleen tumour, he will do a blood test to get a complete blood cell count. He will also test the dog's urine. After that, the veterinarian might use X-rays or ultrasound to look for tumours. He will make the final diagnosis by taking a tissue sample from the tumour to determine what kind of cancer it is if it is malignant. This will require exploratory surgery.
Surgical removal of the spleen along with the tumour is the recommended treatment. Just like people, dogs can survive without their spleen because the liver will do the spleen's job for it. Unfortunately, if the tumour was malignant, it most likely had spread to other parts of the body before it was diagnosed.
Chemotherapy is also an option. There can be strong side effects because the drugs that are usually given are toxic to organs that divide cells, including the intestine, bone marrow and skin. Not all chemotherapy drugs are available in every country and they have to be handled carefully because they are dangerous to humans and other animals.
If the tumour is benign, then the dog should lead a normal life after the spleen is removed. Dogs with malignant tumours that have had surgery and chemotherapy live for an average of 3 to 9 months. Remissions of up to a year following chemotherapy are not uncommon, but this depends on the type of cancer and how far along it was when the tumour was removed.