tumor in the anus?

Question
my guinea pig has what appears to be a tumor growing in his anus. his anus is extremely swollen and there is a crusty layer of gunk around it. he is also drinking excessive amounts of water daily. he's about 5 years old.

Answer
Hello KC,

I'm very sorry it has taken me so long to respond. I have been very ill the last few days. Again, I am terribly sorry for the delay. He may have an impaction. Sit him in your lap on his back. Gently open his sack and clean it out with a bit of mineral or baby oil on a cotton swab or a warm damp wash cloth. Warning: This is a very stinky, yucky task. I recommend doing it in the bath tub or other spot that is easily cleaned. As boars get older, impactions are more common and this is likely his problem now. He'll need to be checked for impactions and cleaned out at least once a week. Some boars will actually need to be cleaned everyday. Once cleaned out, he should be fine. If this doesn't solve the problem however, take him to the vet. He could have a tumor. I do think an impaction is more likely though. Once again, I'm sorry for the delay in answering.

-kkat
www.geocities.com/abyssinianguineapigs