I'm Dr. Jo and I'm a licensed vet with more than 20 years of experience.
As much as I hate delivering bad news, I'm afraid I have to tell you that the answer to your question is unfortunately, no. You can only get a prescription from the vet who has seen and examined your pet. I want you to know, however, that it's as simple as asking your vet for a written prescription, then you can have it filled at any pharmacy of your choice. Some vets charge a small fee for this service, however.
I have to admit that's pretty pricey for Cerenia, enough so to make me wonder if there's been a mistake.
Even though confrontations can be difficult, please contact your vet to ask about the situation... if there was a mistake, and if there was not, to ask for a written prescription so you can have it filled elsewhere.
Other than that, your only remaining option is to shop around for a different local vet.
I'm sorry to disappoint you, but know it's important to be honest in thorough in providing you the information you are looking for.
I do hope this information has been helpful.
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