The stray I took in a month ago started vomiting yesterday and has really bad diarrhea, after 24 hours it did not clear up so I took him to the vet today, he got a Cerenia injection to stop the vomiting and now is exhibiting 2 of the side effects of it, lethargy and now he does not want to eat. Has anyone had the same experience and if so how long do the side effects last? X-ray and blood work did not show anything unusual but they found a small amount of Clostridium in the poop so he is now on Metronidazole and some probiotic.