Signs of Tumors in Dogs

By MelissaBielawski

While more common in older dogs, tumors may occur in canines of all ages and breeds, including puppies. Both malignant and benign tumors can cause a problem for canines, and it is important to be aware of the symptoms in order to facilitate early diagnosis and treatment. Various physical, psychological and behavioral symptoms can be indicative of a tumor in a dog.

Physical Symptoms

There can be obvious physical symptoms when your dog has a tumor.

Tatyana Aleksandrova/iStock/Getty Images

Different types of tumors can create many physical symptoms in canines. In the case of mast tumors, the most common tumor in dogs, there may be vomiting, blood in the stool or ulcers, according to pet information hub In larger dogs, problems with blood clotting may be another symptom. Physical signs of a brain tumor include loss of balance, trouble walking, weakness, loss of appetite, extreme thirst, unintentional urination, facial paralysis, seizures and vomiting, according to Extreme discomfort or pain is shown through whimpering or crying. Loss of weight and abdominal extension may be a symptom of a tumor in the abdomen, while bone tumors often cause frequent discomfort or pain in the leg, according to dog cancer research charity Land of Pure Gold Foundation. Recurrent nose bleeds and facial swelling may indicate a tumor in the nasal cavity. Blood in the urine or a soft lump in the testicles is indicative of testicular cancer in canines.

Psychological Symptoms

Your dog may also exhibit psychological symptoms.

gpointstudio/iStock/Getty Images

Psychological symptoms such as a change in personality, general confusion and compulsive behavior may be indicative of a brain tumor, according to Compulsive behavior includes excessive barking or uncontrolled eating. A dog sometimes becomes disoriented or acts unsettled and may suffer from confusion in familiar surroundings. An example of this is the dog can't find his way home or fails to recognize well-known voices and people. Depression and irritability are other psychological symptoms of a tumor in a dog.

Behavioral Symptoms

Changes in general behavior can indicate the presence of a tumor.

Fuse/Fuse/Getty Images

Changes in general behavior is another indicator of a tumor. Brain tumors may cause an overall reversal in behavior, according to, with typically gentle dogs acting aggressively or aggressive dogs becoming extremely docile. A brain tumor can cause unusual behavior, such as refusal to eat, extreme apathy to the dog's surroundings, or a loss of learned habits like not using the bathroom in the house. Dogs may become disinterested in favorite activities, such as playing or exercising. In the case of a pain-causing tumor, a normally placid dog could undergo a change in temperament and become abnormally hostile to regular human interaction.

Visible Symptoms

Sometimes the tumors will be visible.

Chalabala/iStock/Getty Images

In some cases, tumors are visible to the naked eye. Mast tumors are the most common type of growth found in a canine, according to the Land of Pure Gold Foundation, and they can occur on any part of the body. Most frequently these tumors are found on the skin or just below the surface of the skin. When on the skin, a mast tumor looks like a raised pink lump. In the case of testicular cancer, the testes become visibly enlarged.