Anal gland cancer in dogs, symptoms, causes and treatment for anal sac disease in dogs
Anal sac adenocarcinoma, also often known as anal gland cancer, is a type of tumor that sometimes develops in the anal sac of a dog.
Anal sac adenocarcinoma in dogs is extremely rare, but when it does occur it is extremely aggressive – large tumors are often fatal, and even smaller tumors tend to recur after they have been surgically removed. This type of anal sac disease in dogs is more common among certain breeds, such as dachshunds, German shepherds, and English cocker spaniels.
Female dogs are also more susceptible, particularly after the age of 10 years.
One of the most common symptoms of anal gland carcinoma in dogs is hypercalcemia, particularly in females. This is essentially an elevated level of calcium in the blood, which leads to increased thirst and urination, weight loss, and decrease in appetite.
Sometimes the anal gland tumor may itself cause symptoms such as difficulty in passing stools, which leads to constipation and/or straining. However, this usually happens only with larger tumors – smaller tumors will usually not affect bowel movements, and tend to be detected in the course of routine examinations.
The causes of anal gland tumors in dogs are not very clear, but some experts believe that certain breeds may be more susceptible to this type of cancer. It is therefore advisable to be aware of the health risks that are common to your breed of dog. If your dog has a high risk of developing anal sac adenocarcinoma, rectal examinations should be made part of regular health check ups. Some experts believe that neutering reduces the risk of developing these tumors, although some studies have found no difference between neutered and in tact dogs. However, when combined with all the other benefits of neutering, the chance of decreasing your dog's susceptibility to anal sac adenocarcinoma makes neutering advisable.
Anal sac adenocarcinoma is an extremely dangerous type of cancer, and the only viable treatment option is surgical removal of the entire tumor and any lymph nodes that have been affected. Anal gland surgery in dogs is usually supplemented with chemotherapy and radiation in order to decrease the chances of the tumor recurring. Unfortunately, in spite of all this treatment, most dogs eventually succumb to the disease, although survival can extend up to three years. If the tumor is very large or has metastasized however, the prognosis will be poor – some dogs survive only a few weeks after the diagnosis.