Welcome! My name is Dr. Andy. I am a 2003 graduate, and currently a Medical Director of a veterinary hospital.
I am sorry to hear about this concern for Daisy.
I am not concerned about the extra dose.
In fact, when vets are treating a coccidia infection, the first day dose is twice what the remaining days are. So, to get the extra dose is not really of any concern.
I am not worried about any toxicity, but I still always advise to keep an eye
out for any vomiting or diarrhea. If any symptoms come up, I would advise your vet for some extra supportive care, but should be fine.
I hope that information has been helpful.
Please remember to select Reply to Expert, if for any reason you need further clarification, have more questions, or were expecting a different type of answer. Prior to leaving a feedback rating, which I greatly appreciate, my goal is to provide you the best answer possible.