The Symptoms of Mast Cell Tumors in Dogs

Mast cell tumors, which are common in older canines, are masses of cancerous cells. Although they are seen most in older dogs, dogs of any age and breed can develop mast cell tumors. Knowing the signs of a mast cell tumor can help you catch it as early as possible and seek the appropriate medical attention for your dog.

  1. Lumps

    • Mast cell tumors present as lumps under the skin of your dog. According to Kate Connick's Courteous Canines website, tumors are usually located on your dog's trunk, but they can be located elsewhere. The tumors themselves are groupings of cancerous cells that come together and form masses. Sometimes you will find one tumor and other times you will find multiple tumors grouped together.

      Mast cell tumors have the ability to change size, sometimes from day to day, according to the Canine Cancer website. Most tumors are not painful, regardless of the size or changes that occur. However, from time to time, the mast cell tumors can become inflamed, causing pain to your dog. Occasionally, the pain is triggered by a histamine release that occurs when the tumors are touched, but they can be painful even without this histamine release.

    Digestive Symptoms

    • Not every dog will develop the same set of symptoms with mast cell tumors or to the same degree. Yet, some dogs will develop digestive problems, which are a common symptom. Kate Connick's Courteous Canines points out that digestive problems are often linked to the location of the tumors. Tumors can cause your dog to develop abdominal pain, which can lead to diarrhea and a loss of appetite. Sometimes a dog will vomit, and sometimes blood can be seen in the vomit. Blood is also common in the feces of the dog. Bloody feces present as dark or black feces.

    Other Symptoms

    • Depending on the location and the stage of the tumor, other symptoms can occur, according to Canine Cancer. For example, if the tumors are near the lungs, breathing problems or coughing can occur. Other common symptoms include bleeding problems, which lead to trouble with wound healing, swollen lymph nodes or high blood pressure.