Q. My cat is normally very spunky, playful and full of energy. He eats when he comes inside from being out. He won't eat today I've found 4 ticks on him
A. Warm the food before feeding or mix in some baby food to stimulate the appetite. If he doesn't begin to eat again, have him seen by your vet. Lyme disease is uncommon in cats, however, there are other tick borne diseases that can infect your cat. Use a topical preventative such as Frontline or Revolution to control fleas and ticks if your cat goes outdoors.
DR. CHRISTIE LONG, D.V.M., C.V.A.
A. I'm concerned about what could be going on in your cat for a couple of reasons. First, he's been outside, and certainly there are quite a few things that could be on related to that - he could have been in a fight, he could have sustained a fall or other trauma - and he might be not wanting to eat because he's in pain, or because he has an abscess forming from a bite.
The other concerning thing you mentioned is the ticks. Not knowing where you live it's difficult to guess what type of ticks they could be, but ticks certainly carry infectious diseases and although cats typically aren't infected in the U.S. I don't know about other countries. Plus if there are ticks where you are there are probably fleas as well, and cats can definitely get diseases from those.
I think it's important to take him to your vet for an exam so that he can check his temperature, see if he's in pain, and perhaps run some tests to see what's going on. Like you said, it's unusual for him to be this way, so you should get him to a doctor who can figure out what's going on.