Information on Spleen Tumors in Dogs

Hemangiosarcoma is a common splenic tumor in older dogs, particularly in large breeds such as German shepherds, golden retrievers and Labradors.

The spleen removes and destroys worn-out blood cells and helps fight infection. It is fist-sized and spongy, and is situated behind the lower ribs in the upper-left abdomen. This dark-purple organ enlarges as a result of many diseases, including infections and tumors. The most common splenic tumors, or masses, are hemangiomas, hemangiosarcoma, hematomas and splenic torsion. According to the American College of Veterinary Surgeons (ACVS), "Up to 67 percent of dogs with splenic masses have a malignant tumor."

Hemangiomas

According to the Merck Veterinary Manual, "Hemangiomas are benign proliferations that closely resemble blood vessels. Whether these are neoplasms (new abnormal growth---malignant or benign), harmartomas (benign tumor-like masses), or vascular malformation remains undefined, and no clear criteria exist that allow for their separation." As a result, the ACVS recommends removal of the spleen (splenectomy) as it serves as "both a diagnostic and therapeutic procedure." Hemangiomas can have a presentation similar to hemangiosarcoma and, therefore, need to be correctly diagnosed.

Hemangiosarcomas

The National Canine Cancer Foundation (NCCF) states that hemangiosarcoma (HSA) "is an incurable tumor of cells that line blood vessels." According to the ACVS, it is a common splenic tumor usually seen in dogs who are eight to 10 years of age. The NCCF estimates that as many as 2 million dogs may die annually from HSA, with large breeds particularly susceptible. At-risk breeds include German shepherds, golden retrievers, Labradors, poodles, Portuguese water dogs and Skye terriers, among others.

Hematomas

A hematoma is a localized collection of usually clotted blood resulting from a ruptured blood vessel. According to the American Medical Association, hematomas can vary from a minor to a potentially fatal disorder, depending on the site and amount of accumulated blood. The ACVS notes that hematomas are one of the most common non-neoplastic (meaning not a tumor) lesions, accounting for 20 to 41 percent of all splenic lesions. Veterinarians recommend surgical removal of splenic hematomas, which usually corrects the problem and avoids a splenectomy.

Splenic Torsion

The ACVS says that splenic torsion occurs "when the spleen rotates/twists, thus preventing blood drainage, which causes enlargement of the spleen. It may occur on its own (rare) or in combination with gastric dilatation-volvulus." It occurs in deep-chested, large and giant breed dogs such as Great Danes and German shepherds. Signs can be acute or chronic---from pain and collapse to vomiting, abdominal distention, weight loss and excessive drinking. Veterinarians recommend splenectomy, which usually results in a good prognosis.

Treatment

Signs of a canine splenic tumor may include weakness, abdominal distension and weight loss.

Whether HSA, hemangioma or splenic torsion, the recommended treatment is removal of the dog's spleen. According to the ACVS, in all instances of splenectomy, the veterinary surgical staff stabilizes the patient prior to surgery, which may include fluid therapy or a blood transfusion. As with all surgeries, complications do occur, with the most frequent being hemorrhage, cardiac arrhythmia and pancreatitis. If your dog exhibits signs of abdominal distention, weight loss, fainting, weakness or pain following surgery, contact your veterinarian immediately.

References

• "The American Medical Association Encyclopedia of Medicine"; The American Medical Association; 1989
• American College of Veterinary Surgeons: Splenic Masses in Dogs
• The Merck Veterinary Manual: Vascular Tumors
• National Canine Cancer Foundation: Hemangiosarcoma
• Canine Cancer Awareness: Hemangiosarcoma

Resources

• Canine Cancer Awareness