My cat, Icarus, is a little more than a year and a half old. He's always been slightly overweight, but ever since we adopted a new kitten into the family (about a week ago) he has seemed to really blow up. He stepped on my scale the other day and weighed 18 pounds (!!!!) Now, the problem is that his stomach isn't more fatty. It doesn't feel like fat around his middle, it just feels like his normal stomach--taught with a little bit of fat. But the circumference of his stomach has increased tremendously. So, I'm wondering: could Icarus have worms or some other internal parasite that's making him so large? He's an inside cat that hasn't been outside of our apartment, or introduced to anything new other than the kitten, in more than three weeks. By the way, the kitten seems healthy (albeit very skinny) and doesn't appear to have any parasites.

On a possibly unrelated note, Icarus also has lots of tiny black dots at the base of his tail. We think its possibly flea eggs or feces and we don't know how to treat them.

Any help at all would be great. I don't wanna take him to the vet if there's nothing to worry about.