By: Dr. Al Townshend
Both dogs and cats have two anal sacs, one on either side of the rectum. Within the lining of each sac are sweat-like glands that secrete a dark, foul-smelling substance that is expressed each time the pet has a bowel movement. The liquid acts as a scent marker and helps to identify the animal to others.
The tumors originate in the glands within the anal sac. The most common cancer is an Adenocarcinoma of the anal gland. They are highly malignant and have the potential to invade adjacent tissue and spread throughout the body. Regular home examinations of pets should include the area around the rectum. The tumors can grow quickly and reach a size that makes them difficult to remove completely.
Signs
While anal gland tumors are uncommon, especially in cats, they occur in males and females. Older animals are most commonly affected. There is a higher incidence in the spaniel breeds.
As with all cancers just under the skin, the first sign of a problem would be a small lump beside the rectum. As the lump grows, it may create difficulty for the pet to have a bowel movement and increase the risk of constipation.
Diagnosis
Diagnosis is generally made with a biopsy of the tissue or by removing the entire mass and having it reviewed by a pathologist. Proper identification is essential to the treatment.
Treatment
Local treatment involves surgery to remove the primary growth and to examine the surrounding tissue and lymph nodes. A pathologist will examine all tissues, and if the growth has spread, chemotherapy or radiation may be indicated.
Additional tests to determine if the tumor has spread to other parts of the body can include Xray’s, scans, blood tests, and other diagnostics.
Radiation and chemotherapy have been used to reduce the size of the tumor before surgery.
The prognosis is guarded because of the potential for the tumor to spread.
Prevention
Regular at-home exams help to assure catching any growth early, which always improves the potential for a successful outcome.
Annual veterinary checkups and working closely with the veterinarian can also assure the best outcome.
More Pet Cancer Information Here.