Hi My ,ittle Man Got Sterilized On Tuesday. The Wound

Hi my ,ittle man got sterilized on tuesday. The wound looks clean and good and he was fine wednesday but then started not wanting to eat even the reats he inhaled before. He is axtive, plays with me and is not irresponsive. This morning he had a few nibbles of his dry food but not much. I tried canned food even biught a/d but he wont eat it. I managed to get a couple of small syringes with a/d in his mouth and he swallowed it. He is six months old