Cerenia and penicillin

my dog got a penicillin and cereni shot today because she was throwing up. Now she is very weak and lost her appetite are these normal side effects or should i be worried? she is usually a very active dog and the past few hours she has just been sleeping.

[ginger899]

Did you take her to the ER vet, or the regular vet when she got the shots?  (the reason I ask is just sometimes, if an emergency vet is used, the symptoms are dealt with very quickly, and a full diagnosis not always done)

What did the vet say might be wrong with her? Why was penicillin prescribed? Did the vet suspect an infection of some kind?
So, basically, what was the issue apart from vomiting?

Cerenia has been known to cause lethargy sometimes, and it's possible it could cause loss of appetite....likewise occasionally antibiotics can do that.

But I really do think you need to speak to your vet as soon as they open Monday morning, if she is no better by then.
Do try to make sure she's drinking water. If dehydration sets in there will be trouble. If you cannot get her to drink anything at all, then she will definitely need re-hydration probably by IV. But if you can tempt her with anything liquid....water...pedialyte, unsalted chicken or fish stock, or water with a little maple syrup or honey added....anything to keep dehydration at bay.

This could be side effects of her medication, or it could be the underlying illness that she is receiving treatment for. It's hard to tell. Just keep a watchful eye on her, make sure she gets fluids, call your vet for advice Monday morning, and if there is any deterioration in the meantime, get her to emergency.
I hope she is better very soon.