I had my cat neutered 2 weeks ago. Before this was done he was wild and running around everywhere and begging to get outside.(He stays indoors all the time). Now all he does is sleeps a lot. He doesn't cry to get out or play much. He has changed so much it started the day he came home from the vet. Is this normal or does neutering an animal at the age of 2 seem to depress them. He eats just fine. Should I be concerned or will time take care of this?