My two year old cat came home one day and did nothing but sleep... for about a week. Didn't eat or drink anything for about five days. Had a little water on the fifth day.Didn't move. Didn't meow or respond at all. On the seventh day he got up and had some tuna and was fine for about twenty four hours and again went back to the same sick sleep pattern. Now he can't even walk without falling over. Doesn't seem to have any control of his muscles, his front legs are stiff in front of him when he lays down.he barely responds when I say his name or pet him.HIS EYES ARE MATTED AND HE BREATHES REAL HARD.do you think he might have had a seizure

Hi Bestboo,
You need to take your cat to a veterinarian as soon as possible. It is impossible to say what is going on, though given the altered respiration and leg posturing, he is definitely suffering an affliction of the central nervous system.
Is his rabies shot up to date? Have you checked under his fur for any hidden bites or other puncture wounds of any sort? You definitely need to get him some medical care promptly.
I hope everything turns out okay. Keep us updated.
Take care.