Cancer in Boxer Dogs

Boxers are lovable, clownish and devoted -- and also one of the dog breeds most prone to cancer. It's likely that the high cancer rate in boxers results from a genetic predisposition. Studies, some of them underwritten by the American Boxer Club or the American Kennel Club, are trying to determine why boxers get cancer and provide better treatment options for the disease. Four types of cancer are particularly prevalent in boxers.

Dog looking away, close-up
Boxers are genetically predisposed to certain cancers.
credit: Chris Amaral/Digital Vision/Getty Images

Boxer Hemangiosarcoma

Unfortunately, by the time a boxer is diagnosed with hemangiosarcoma, or cancer of the blood vessels, it's generally too late. This aggressive cancer already has spread throughout the body, and his life expectancy might be as little as two months. In its early stages, hemangiosarcoma has few symptoms, or very subtle ones. Hemangiosarcoma usually originates in blood vessels in certain organs, usually the spleen, skin, heart or liver. It often metastasizes to the lungs. Symptoms include breathing problems, appetite and weight loss, lethargy and anemia. Treatment consists of tumor removal, if possible, but this will only buy the dog some additional time, not cure him.

Lymphoma in Boxers

Approximately 25 percent of all boxers eventually will develop lymphoma, or cancer of the lymphocytes. These white blood cells, part of the immune system, are designed as disease fighters. Signs of lymphoma include lymph node swelling, appetite and weight loss, breathing issues, a distended abdomen due to fluid accumulation, fever and excessive drinking and urination. Your vet will conduct a tissue biopsy, along with X-rays and ultrasounds, to make a diagnosis. Treatment consists primarily of chemotherapy. The prognosis depends on far along the disease was at diagnosis. Since lymphoma generally occurs in older dogs, some boxers might live close to a normal life span. Others may succumb within a few weeks or months.

Brain Tumors

Unfortunately, boxers lead all other breeds in the development of brain tumors. Otherwise known as gliomas, these tumors begin in the brain's glial cells, killing off nearby brain tissue as they grow. While some gliomas grow relatively slowly, others are quite aggressive. Signs of a brain tumor in a boxer include seizures, constant circling, personality changes, general unsteadiness and head tilt.

Once confirmed via a computed tomography scan, a veterinary neurologist can biopsy the tumor. Actually removing the tumor is difficult, since removal usually affects adjacent brain tissue. Treatment consists of radiation therapy sessions and medications to control tumor side effects, such as seizures. With treatment, dogs might survive close to a year or more.

Mast Cell Tumors

Boxers are prone to mast cell tumors, appearing on the skin. Formally known as mastocytoma, these tumors affect the connective tissue. Symptoms include a lump, either on or under the skin, which may change in size. Some tumors might initially look like a bug bite. The tumor might build up fluid or appear red, and the dog might scratch at it.

Mast cell tumors are graded on a scale of 1 to 3 based on several factors, including location, size and any inflammation. A grade 1 tumor is unlikely to spread, while a grade 2 tumor can metastasize locally. A grade 3 tumor is likely to metastasize. Diagnosis is made via fine needle aspiration of the tumor and a subsequent biopsy. Treatment usually consists of surgical removal of the tumor, followed by chemotherapy. Prognosis depends on whether the tumor has metastasized to other parts of the body.