Horsie Is Feeling Bad..(I think!)

You know how it is..you get used to an animal, and when they are off, you can tell..nothing specific, (wouldn't that be nice?) but he just isn't acting himself. He is eating and drinking...and he goes outside to go to the bathroom, so I don't see that, to make a judgement...he is sleeping more inside...he is often inside sleeping, even when I am outside (he used to always join me) usually when I take a bath, I open the bathroom window, and he comes and hops up on the window sill and just sits up there and watches the activity outside (he is behind a hedge, so no one can see him) but lately he is on his bed sleeping and when I ask him if he is okay, he chirps, no meow, just a chirp...he doesn't appear to be grooming himself as much as usual...he has leaves and twigs in the fur on his butt...and that is another thing, he is letting me actually check out such things! and that is real unusual for him...I guess I should take advantage of this and see if I can get some of the mats clipped out. He will be 8 years old this July so maybe he is just begining to slow down? I hate to even think of that. But a hunt and search mission at the Vets would be an expensive thing, and I don't have the $ right now. I think Dr. Randy would let me pay him later, but I am not sure when I could, so I would hate to do it for that reason...I know he is always an option in a true emergency, the man has even made house calls before, for another cat I used to have...he actually kind of house/cat sat for me, at no charge! He is a wonderful man.
So Horsie...he is on his bed sleeping now...he came inside an hour ago, and walked right by me, and went to his bed (one of them). I listened to him eat, before he went to the back of the house (that is where his water is, we keep a glass on the edge of the tub,, for him) so he probably drank some water, too.
I am going to get some scissors and work on his mats...wish me luck!