It's possible he has pain from the injection site. He might be feeling sore. Can you tell if there is any redness or swelling at the site? There may be a small lump, but that is normal as long as there is no swelling or redness.
I would watch him, and if he isn't better in the morning, call the vet. Of course, if he starts acting any worse, I wouldn't wait. Good luck! I will say a prayer for him! |