OVERVIEW
Anal sac adenocarcinomas are tumors arising from the apocrine glands present on either side of the rectum. They occur primarily in older (average 10 years) female dogs. Dogs might have symptoms such as straining to have bowel movements (either due to the tumor itself or due to enlarged lymph nodes in the pelvic area), or the tumors might be found incidentally on a routine physical examination. Sometimes dogs may have symptoms such as increased drinking and urinating which results from very high calcium levels in the blood (due to hormones produced by the tumor) which in turn can affect the kidneys.