Your dog's spleen is located near the stomach. Its purpose is to filter the dog's blood, and it plays a role in your pet's immune system. This is the organ where red blood cells are made and stored and old and abnormal blood cells are removed. The spleen also traps and removes bacteria and foreign proteins. Several diseases and disorders can begin in the animal's spleen, and spleen disease also can be a symptom of other disorders.
Symptoms of a spleen disorder include pale gums and, frequently, accompanying pain. Many dogs with an enlarged spleen will refuse to lie down. Often, the dog's abdomen will be distended and a hard mass can sometimes be felt in the abdomen area. The dog may be weak and anorexic. Diarrhoea, vomiting and lethargy may also be present.
Diagnosing a disease in the spleen usually begins with a complete blood count and other diagnostic tests. The veterinarian may order an ultrasound and do a fine needle aspiration or biopsy. Occasionally, surgery may be needed for diagnosis, and during the surgery the spleen may be removed. The spleen is not necessary for survival and many animals with non-cancerous conditions regain health once it is removed.
An enlarged spleen can cause immune system disorders, anaemia, too many red blood cells and infection. Possible causes of an enlarged spleen include medications, blood clots, bleeding disorders, some types of anaesthesia, stress, shock, parasites, cancer, infection and tumours.
The spleen can become enlarged or congested when a dog has torsion of the stomach. This is a serious condition most common in large breeds and in breeds with deep chests. When torsion is present, the dog's urine may be a dark red-brown colour.
Hemangiosarcoma is a malignant cancer that occurs in middle-age and older dogs. Most common in large breeds, this cancer begins in the spleen and is often fatal. Other types of cancer such as mast cell tumours, multiple myeloma and lymphosarcoma can also begin in the spleen.
Other conditions for which spleen disorders may be a symptom include abdominal injury, hepatitis, various infectious diseases and inflammatory bowel diseases These conditions do not begin in the spleen but do affect the organ's health.
If your dog's spleen must be removed because of disease, the animal is likely to recover within several days of surgery. If cancer is not present, the dog has a good prognosis. However, if cancer is found, many dogs survive only six to eight weeks after surgery.