Apocrine Sweat Gland Tumors in Dogs

While apocrine sweat gland tumors in dogs are relatively rare, they pose a significant threat to the health of the dog due to the fact that these tumors may not present symptoms until they are large in size, making them more difficult to treat successfully.

  1. Identification

    • The apocrine sweat gland tumor is also known as the anal-sac tumor. This tumor is highly malignant, and often spreads to other organs such as the liver, kidneys, spleen, lungs, and lumbar vertebrae as well as the lymph nodes.

    Symptoms

    • Two tell-tale symptoms are associated with apocrine sweat gland tumors in dogs. One is tenesmus, which is an urgent need to urinate or defecate without producing urine or feces. Dogs that exhibit this symptom usually have a large anal-sac tumor that has spread to the lymph nodes. Another symptom of apocrine sweat gland tumors in dogs is hypercalcemia. Hypercalcemia is a condition in which the dog has an elevated amount of calcium in the blood. Apocrine sweat gland tumors are one of the most common causes of hypercalcemia in dogs, second only to lymphoma.

    Risk Factors

    • At one time, it was thought that older female dogs were at an increased risk of developing apocrine sweat gland tumors. However, it is now known that there is no gender predilections with this condition. Apocrine sweat gland tumors affect male dogs as well as females. Certain breeds have been found to have a higher incidence of this type of tumor. These breeds are the Dachshund, the English Cocker Spaniel, the Alaskan Malamute, and the German Short-hair Pointer.

    Diagnosis

    • A veterinarian may perform a needle aspiration of a tumor or cyst on the sweat gland in order to determine if it is malignant (cancerous) or benign (non-cancerous). The veterinarian will examine a sample of cells taken from the tumor under a microscope; if abnormal cells are present, the tumor is malignant. Other tests that may be performed include a complete blood count (CBC), chemistry profile, abdominal ultrasound, and X-rays of the chest and abdomen.

    Treatment

    • Surgery is recommended for dogs that have an apocrine sweat gland tumor. This may include removing the tumor and the surrounding lymph nodes if the cancer has spread. The success of this type of surgery depends on the size of the tumor and the overall health of the dog. The largest risk associated with lymph node removal is excessive bleeding. Surgery may be followed by radiation therapy to keep the tumor from growing back. Radiation therapy may also be performed on dogs that are not candidates for surgery, due to health issues.