Your location: Home > Wiki > Dog Health, Dogs > Dog Mast Cell Tumors >

Dog Mast Cell Tumors

Veterinarian Reviewed on March 29, 2014 by Dr. Janice Huntingford

Dog Mast Cell Tumors

Mast Cells are cells that are normally produced by a dog’s body. They help the body to respond in situations such as Dog Allergies and inflammation. Although necessary for normal function of the body, they can be harmful to the body when produced to an excessive degree.

Mast cell tumors can reproduce quickly in the body and spread quickly. The release of chemicals that are produced by the mast cells can significantly damage other organs. They can produce internal bleeding, gastric ulcers and a long list of allergy reactions. The only way to accurately diagnose mast cell tumors is via a biopsy. There are times that the tumors can be very aggressive and other times they will be innocent. Close observation by the veterinarian is a must.

This type of tumor can develop on any organ or on the surface of the skin. The most common occurrences are on the limbs, abdomen and thorax(chest). There are dog breeds that are more prone to mast cell tumors. These breeds are the Boxer, Pug, Labrador Retriever, Rhodesian Ridgeback, and the Boston Terrier.

They appear as nodules that can be soft or hard. Usually you will note dark granules within the mass. The granules are the part of the tumor that produces the harmful substances. If there is enough dispensed into the blood, it can result in the dogs untimely death.


Although most cancer causes are unknown, it is believed that mast cell tumors have a genetic predisposition. Some other breeds that are commonly struck with mast cell are the Bulldog, Bullmastiff, Dachshund and Standard Schnauzer. The Boxer dog is actually the most prone dog breed. There are some studies that indicate the color of the dogs coat may have some significance in the formation of the tumors. Environmental exposure, some viruses or other undetermined causes can be factors. Middle aged dogs are more prone to the disease.

Signs and Symptoms

The most obvious symptom is the appearance of the tumor itself. They can be single or multiple in their discovery. Just looking at the tumor is not an accurate way to diagnose and a biopsy of the mass must be done by the veterinarian. After the initial tumor is found, it is not unusual to find more of them on the dog’s legs. If allowed to develop without treatment, the tumors can be very irritated and can become ulcerated.

The symptoms that may appear in other parts of the body will depend on the location. There can be a Dog Loss of Appetite, bloody Dog Vomiting, abdominal pain, dark stools. There are many other symptoms that can accompany the mast cell formation. Most importantly is the need to consult with your vet if there is any change in your dog’s activity level or excretions.

Treatment Options

Treatment depends on the stage of the disease. Surgery may be done if the tumor is a single tumor and has not spread. If they have spread through the surface of the skin or body organs, radiation and/or chemotherapy may have to be done. The aggressiveness of the tumors needs to be evaluated before any treatment can be prescribed.


Once a dog has had mast cells, it is not unlikely for them to return. The stage of the disease plays an important part in the recovery and survival. Early diagnosis is very important.

Suggested Products

Stimmune for Dog Allergies
Cancer Support Kit for Dogs
Nu-Pet Vitamin and Anti-Oxidant Wafers for Dogs

Additional Dog Cancer Pages

Dog Cancer | Dog Skin Cancer | Dog Lung Cancer | Dog Bladder Cancer | Dog Pancreatic Cancer | Dog Bone Cancer | Dog Cancer Prevention | Dog Cancer Diagnosis | Dog Lymphoma Cancer | Dog Gastric Cancer

Read also: Dog Oral Fibrosarcoma
154 people found this article useful. Did you find this article useful? Yes

Our Expert

Dr. Janice Huntingford
Janice Huntingford, DVM, has been in veterinary practice for over 30 years and has founded two veterinary clinics since receiving her Doctor of Veterinary Medicine at the Ontario Veterinary College, University of Guelph. She has studied extensively in both conventional and holistic modalities. Ask Dr. Jan

Related Product

Nettle-Eyebright Gold alleviates seasonal allergy discomfort, supports your dog's immune system, and also helps manage fatigue or recurring infections.

Related Posts