Anal Gland Cancer in Dogs

Anal sac problems in dogs are very common. Fortunately, dog anal gland cancer is not nearly as common. However, these anal gland adenocarcinomas are almost always malignant, meaning that they metastasize into other areas of the body. If you suspect an anal gland problem in your dog, immediate examination by your veterinarian is warranted in order to achieve early detection.

Anal Gland Cancer in Dogs

How to Recognize Anal Gland Cancer In Dogs

You may first notice that your dog appears to be constipated as he strains more to defecate. This is because the tumor has grown to the point of pressing along the rectum and partially obstructing the passage through which stool is excreted during defecation. On closer inspection of your dog’s rear end, you may observe a lump on one side of the anus. Since anal gland tumors grow from the inside, the tumor is probably considerably larger than what you are seeing. Such anal sac problems in dogs lead to other symptoms as the cancer progresses. Some of these symptoms include an increase in water intake and urinary output and slowed heart rate. An abnormal level of parathyroid hormone often accompanies dog anal gland cancer. Another common finding with cancerous anal sac problems in dogs is an increase in calcium in the blood, which is called hypercalcemia, and this condition results in kidney failure.

Causes of Anal Gland Cancer In Dogs

The exact cause of anal gland cancer remains a mystery. Anal gland cancer is more prevalent in dogs than in cats, and it occurs equally among male and female dogs. Any breed can be afflicted, but there is a higher incidence of dog anal gland cancer among Cocker Spaniels. Anal gland adenocarcinomas almost always develop on only one side.

Diagnosis of Anal Gland Cancer In Dogs

Your veterinarian may aspirate a preliminary sample of cells from the tumor with a needle and syringe. These cells are deposited onto a slide for examination under a microscope. This test is called a cytology, and it is often a first step toward diagnosis. If the cells are suspicious, then surgical removal of the tumor will be necessary in order for sections of the tumor tissue to be analyzed in another test, called a histopathology. The resulting report will confirm the dog anal gland cancer diagnosis, providing the grade of the tumor, the prognosis and other pertinent information that will determine the most effective course of treatment. Since a blood chemistry panel is needed for anesthesia prior to surgery, your veterinarian will be able to assess your dog’s parathyroid hormone and calcium levels. An abdominal ultrasound and chest radiographs will also be performed prior to surgery to determine if the cancer has spread to other major organs, such as the liver, kidneys, heart and lungs.

Similar Symptoms

Dog glands problems occur in many dogs. Some dog glands problems of the anal glands include inflammation, impaction and infection. If your dog requires frequent visits to the veterinarian to have his anal sacs manually voided, he is not alone. In a perfect world, the anal sacs should be able to express the accumulated anal gland material on their own, but a lot of dogs need a little help to accomplish this. This is not a sign or a precursor for anal gland cancer. Dog glands problems present with the telltale sign of the uncomfortable dog dragging his hind end on the floor in an attempt to relieve the sacs, a behavior that is often referred to as scooting. It is not a sign of being constipated or having difficulty with defecation.

Possible Conditions

Diagnosis of anal gland adenocarcinoma is straightforward. As soon as you suspect a problem with your dog’s anal glands, have him examined by your veterinarian as soon as possible. Early detection of anal gland cancer will increase your dog’s chances for survival. Your veterinarian will be able to determine with ease whether your dog has an anal gland tumor or impacted anal glands. The malignant state of anal gland cancer prompts an increase in blood calcium levels. This affects the kidneys and presents the warning signs of kidney disease, such as increased thirst, increased urination and decreased appetite. Your veterinarian will be able to differentiate whether the kidney disease is the primary problem or if it is a secondary complication from anal gland cancer.

Treatment of Anal Gland Cancer In Dogs

The first step in treatment is surgical removal of the anal gland tumor and the tissues surrounding it. If there is any lymph node enlargement in the abdomen, then the affected lymph nodes are also removed. Be sure to follow all of your veterinarian’s recommended post-operative care guidelines to ensure a smooth recovery from surgery. If kidney disease has set in, the condition will need to be monitored and treated with a prescription renal diet, fluid therapy and medications. Depending on the extent of the cancer, the overall health of your dog and the grade of the tumor, your veterinarian may recommend chemotherapy, radiation or a combination of both following surgery to provide your dog with the best possible outcome.

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