My mother just called me to let me know that the family dog Sadie has a rectal tumor. Sadie is a German Sheperd (pure-bred) and is 12 years old. Her presenting symptoms were similar to impacted anal glands (which she gets whenever she goes to a kennel maybe twice a year for 2wks max). She has some mild arthritis, but is otherwise active. My parents went on a vacation for about 10days and left her at a kennel (great place, highly recommended; owners love Sadie). When they returned (the 11th), she had blocked anal glands (like always) and Mom took her to the vet to have them expressed (Tuesday the 13th). Sadie seemed ok, but over the weekend, exhibited more symptoms consistent with gland blockage. Mom took her to the vet again today, expecting that she needed her glands expressed again, and the vet appreciated a tumor. Mom assures me that it was indeed a rectal tumor a few inches in (as opposed to uterine). She plans to talk to the vet again tomorrow and make an appointment for a colonoscopy (at Texas A&M - my alma mater!). She called me, since I'm the "medical" person. (4th year med) Sadie is more my sister's dog than mine, and my mom doesn't want to call her (sis lives 1500mi away, coming to visit in 2-3wks) until she knows more. SO, what is the differantial diagnosis for a 12yr old German Shep female with a rectal tumor BESIDES colon cancer? And what are the treatment options? None of us want her to have ANY pain, and we watched the neighbor's dog go through years of chemo (unpleasant). Any suggestions/advice?