Mast Cell Tumors in Dogs-Symptoms, Treatment, Causes, Pictures

Dogs can also have tumors and one of the common types is the Mast Cell Tumors in dogs.  Also known as mast cell sarcoma, histiocytic mastocytoma and mastocystosis, mast cell tumors in dogs are generally considered malignant or potentially malignant mass growths.  It affects any breed of dogs and of any age, but are more common in 8 to 10 years old.  About twenty percent of all skin tumors in dogs are attributed to mast cell tumors.

What are Mast Cells?

Mast cells pertain to the naturally occurring cells in the skin and other parts of the body such as the respiratory tract and intestines.  They are involved in protecting the dog against inflammation and foreign substances invading the body such as allergens as they are part of the dog’s immune system.  Within these cells are histamine, proteolytic enzymes, serotonin, prostaglandins and heparin which help fight any foreign invaders.

When mast cell tumors in dogs form, the same materials found in them could cause harm when released in large quantities, especially to the blood pressure, heart rate and other bodily functions. What’s worse, these tumors often give rise to an assortment of allergic reactions, internal hemorrhage, and gastric ulcers.

Causes of Mast Cell Tumors in Dogs

The exact cause for this tumor is not exactly known; genetic, viral and environmental factors have been cited.  But some breeds are found to be more prone to mast cell tumors.  These include boxers, beagles, bulldogs, dachshunds, fox terriers, Labrador retrievers, golden retrievers, and weimaraners, among others.

Signs and Symptoms of Mast Cell Tumors in Dogs

Mast cell tumors can appear on different parts of the dog’s body, but they are more frequently found in the genital regions, extremities – most specially the posterior upper thigh, and the trunk. There could be just one or multiple nodules present, and may appear rough, smooth or ulcerated depending on the grade.  It could grow on the surface of the skin or underneath it.  A distinguishing feature of a mast cell tumor is its propensity to arbitrarily change in size regularly. In general, these tumors are not painful, unless they are inflamed or ulcerated.

Mast cell tumors in dogs may also cause the following depending on the grade and severity of the disease:

• Reduced appetite
• Vomiting, bloody vomit
• Pain in the abdomen
• Blackish or dark stools
• Itchiness
• Diarrhea
• Anorexia
• Sluggishness
• Fluctuating blood pressure and heartbeat
• Inflamed lymph nodes
• Coughing
• Bleeding problems
• Delayed healing of cuts and injuries
• Labored breathing

Diagnosis of Mast Cell Tumors in Dogs

Only through a biopsy is the presence of the mast cell tumor confirmed.  The diagnosis will determine if cancer is indeed present as well as identify the grade and stage of the cancer.

Grading the tumor

The grade classifies whether the tumor is malignant or not.  The graver the tumor is, the higher the grade will be.

• Grade I – Most cases of mast cell tumors in dogs belong here.  They typically only occur on the skin and are benign.  There is little to no chance of spreading to other areas of the body, and prognosis is good once the tumor has been surgically removed.
• Grade 2 – The tumor grew from the subcutaneous tissues and the skin.  It shows some degree of malignancy; the treatment method to be employed is complex and success is not guaranteed.
• Grade 3 – This is the least common type.  The tumor is aggressive and will likely spread quickly, thus necessitating more aggressive treatment methods.  The prognosis is poor.

Staging the tumor

Staging refers to how the tumor has spread.

• Stage 0 – Incomplete removal of one tumor; lymph nodes not involved.
• Stage 1 – One tumor with clear margins; will not likely spread.
• Stage 2 – One tumor; lymph nodes involved.
• Stage 3 – Multiple tumors; with or without lymph nodes involved.
• Stage 4 – Systemic metastasis is observed; poor prognosis.

Treatment of Mast Cell Tumors in Dogs

The treatment largely depends on the grade and stage of the tumor.  The treatment options include:

• Surgical removal – This method is effective against Grade 1 and 2 tumors as long as the tumor is removed in its entirety.
• Radiation therapy – If surgery cannot remove the whole tumor, this treatment method can be done.
• Chemotherapy – If the tumor has spread to other parts of the body, this can be employed with radiation and surgery.
• Cryosurgery – Best for small tumors, this involves freezing the tumor and the surrounding tissues.
• Photodynamic therapy – A dye that locates the cancer cells is introduced into the bloodstream, and then laser is used to kill the cancer cells.

Because mast cell tumors in dogs could manifest themselves in a variety of ways, it would be wise to consult a veterinarian right away if there are any lumps or tumors found on the pet dog.  Just as in humans, the success of any cancer treatment is largely influenced by the timely diagnosis and treatment of the disease.

Mast Cell Tumors in Dogs Pictures

Check out the pictures or images of mast cell tumors in dogs