It can be given to dogs but I only know if it being given UV and that was in extreme cases and it has to be dosed correctly. I would NOT advise you to give that to your dog.
You need to be more concerned as to the cause of the vomiting. Is the dog sick? Is the dog drinking fluids? As this is an older dog, there could be any number of reasons for the vomiting.
Don't feed the dog or, if you feel you must, you might try a small portion of chicken and rice. Do make sure the dog is getting fluids.
I suggest you give your Vet a call to get the dog examined and some blood work done.
Good luck and please let us know how things go.
Ondansetron CAN be given to dogs, but I wouldn't do it without consulting your vet. There could be problems associated with giving it to your dog without your vet first examining him because if the vomiting is from something serious, such as a blockage or intussusception it could mask the symptoms and this could be fatal for your dog. Also, some breeds, like Collies and breeds that were developed using the Collie could suffer fatal side effects from it. It's just not worth chancing it. Animals are like people in that none of them should be given medication that was not prescribed for them, and in animals it's even more important since they can't tell us if they are feeling bad from taking it, we can only guess from what we can see, and sometimes by the time we notice a problem it's too late to help them. Please wait and contact your vet before giving him anything. If the vomiting is severe take him to an emergency vet tonight, otherwise call your own vet first thing in the morning. Please let us know what the vet says.
Her diet has not changed but she has always had a tendency to lay under bushes. We have only one in the middle of the yard. We are in winter here in Tx. and it is now empty of leaves. So any bugs that would be present are probably gone. There are some small ones that survive even harsh winter. From her reactions it doesn't bother her, but it does look odd and is not natural.