What does it mean when your dog licks his butt for like 90 mins straight?

My dog is an indoor pet and does not drag his butt on the carpet.. sooo I don't think its worms. Any other ideas?

Fleas love the butt area. Check to see if there are any. Bathe with a good flea soap , let stay on about 10 minutes and rinse off well. You can bathe with Dawn dishwashing liquid in a pinch. See if that helps.

Do you take your dog to a groomer? Dogs have these glands around their butt that secret this nasty stuff, and groomers usually squeeze these to rid it of its "poison." If you do not go to a groomer, they say you have to do it yourself. I guess you squeeze at the 2 and 10 oclock positions around the hole. I have had dogs my whole life and only one needed this though. My mom had to ask her vet to find out for sure! Hope this helps!