Loss of Energy and Appetite

Thanks all for the info.  I was  tempted to ask my vet, but needed an objective opinion.  I'm now worried about the possible anemia reaction.  Mine got the shot 4 days ago for an infection and is now totally listless (barely moving around) and not eating much, a lot like what many of you report.  I sure hope this is temporary and not a sign of getting worse, especially since this one was eating fine before the shot. Very confusing when I've read that some call it a miracle drug! 

I'm sorry, but I'm not sure what shot you are referring to.  But if your cat is having an adverse reaction to it, I would definitely contact your Vet.