
Getting drugs at the pharmacy? Buyer beware.
Linda was terrified when her 8-year-old Lab had two seizures. She took Buddy to his family veterinarian, who diagnosed him with epilepsy. The treatment was phenobarbital (15 mg twice daily), a common anti-seizure medication.
Hoping to save money, Linda asked for a written prescription. Once she got to the pharmacy, the pharmacist remarked that the dosage was too high and recommended cutting it in half.
Over the next several weeks Buddy had multiple other seizures. Later, the vet determined that Buddy had irreversible effects from the continued convulsions. Buddy was euthanized.
In another story, a vet wrote a prescription for azithromycin, an antibiotic. However, the pharmacist sent the client home instead with azathioprine — an anti-cancer medication. After one week, the cat had severe bone marrow suppression and ultimately died.
What Went Wrong?
Many veterinary clinics, by choice or by law, allow their clients to take a prescription to a retail or online pharmacy of their choice. Please be careful when taking advice from your human pharmacist without talking to your pet’s veterinarian first.
Trying to be helpful, pharmacists may decide that a drug is too expensive. Uninformed, they may believe that a dosage is too high or too low, and they may change the amount prescribed.
According to the Oregon Veterinary Medical Association (OVMA), which has been following this issue closely, “If a pharmacist has a concern about a drug prescribed by a veterinarian, it is paramount that he or she call the family vet and ask for clarification about the prescription. A pharmacist should only change a veterinarian’s prescription after having fully discussed the issue and obtaining the veterinarian’s authorization.”
The OVMA adds: “It also is fairly common for both online outlets and brick-and-mortar pharmacies to switch a prescribed product for another product because they happen to be out of the prescribed product.” Yet the different drug may harm the pet.
Pets are not people, no matter how much we love them. Recall that chocolate and grapes are safe for humans but highly toxic for dogs and cats. So are multiple human medications, such as acetaminophen and aspirin. Even if a human medication is safe for pets, there may be differences in dosages that a human pharmacist is not aware of.
OVMA Survey Tallies the Problems
Last year, the OVMA launched a fascinating survey among 525 veterinary practices. About 130 vets responded. The purpose was to investigate veterinarians’ experiences with online and brick-and-mortar pharmacies.
Here are a few highlights:
Ninety-five percent of vets allow clients to get their prescriptions filled outside the veterinary practice. We are here to help, so it is not surprising that most vets understand when a client wants to save money by “shopping around” for a better price. It doesn’t mean that we always approve, as we are aware of the other side of the coin: no education, no hand-holding, no manufacturer guarantee, possible delay in starting the medication, possible errors in filling the drug, possible harm to the patient, etc.
Ninety-three percent of practices do not charge a fee when a client gets the prescriptions filled elsewhere. Yet it should not be shocking if a vet did charge for writing a prescription, as there are more steps involved than meets the eye. Typically, here are the steps involved:
- Writing the prescription, which may involve searching through a book to double-check the correct dosage (not all vets are walking encyclopedias). Oh, and somebody had to pay for ordering and printing that prescription pad.
- Asking a team member to make a copy of the prescription.
- Filing the photocopy in the patient’s medical record.
- Going over the prescription with the pet owner.
- Occasionally — too rarely as we will discuss — talk with a pharmacist to clarify the prescription.
- Sometimes asking a team member to check on the patient’s progress at home.
You may feel that family vets already charge for this (free) service. Well, they do not.
About one third (35%) of the vets who responded have “experienced an instance where a retail pharmacy or an online outlet changed a prescribed dosage or medication” for a patient without the vets’ authorization. This is where the real problems can start.
Nearly 17% of patients have “experienced an adverse event that can be related to a change in dosage or type of medication” from the original prescription that was dispensed by an online or retail pharmacy. Sadly, the “adverse event” can include death.
About half of the vets have been contacted by a pharmacist “to discuss concerns with a prescribed dosage or type of medication.” This is pretty good. This may mean there were no issues with the other prescriptions — or that a problem was overlooked.
The full results of the survey are available in this PDF from the OVMA. Other veterinary medical associations, including in Southern California, Idaho, Iowa and Washington State, have launched similar studies and reached strikingly similar conclusions.

A Few Examples Noted by the Survey
Let’s go over five examples of problems discovered by vets and clients the hard way:
1. Lowering the dosage.
A pharmacist lowered the dosage of thyroid medications without contacting the family vet. What commonly happens is that the pharmacist equates an animal’s ability to process a medication in the same manner as a human. Yet there are clear differences.
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2. Changing a prescription.
A vet wrote a prescription for Itraconazole (Sporanox) to treat ringworm in a cat. Ringworm is a highly contagious fungus that can spread between pets, and even from pets to people. However, the retail pharmacy did not carry the drug and dispensed a compounded product that is unreliable and poorly absorbed in cats. Treatment failed for a while. The vet eventually discovered the problem. Who paid the price? The itchy cat.
3. Playing doctors.
A pet owner told a pharmacist that her dog had arthritis; the pharmacist recommended high doses of Tylenol to relieve the pain. What’s the problem here? Only a vet is legally allowed to prescribe a medication for a pet, and only if there is an existing client-patient-doctor relationship. At least the patient was not a cat, in which Tylenol is deadly.
4. Recommending medications to the wrong species.
A pharmacist dispensed Advantix (a tick medication) to a cat owner. Yet this medication is clearly labeled for use only in dogs. Canine flea and tick medications can be extremely toxic to cats. One common complication is seizures.
5. Misinforming clients.
A vet prescribed propylene glycol for hyperkeratosis of the nose in a Lab. This is a condition where the outer part of the nose is thick and irregular. The pharmacist scared the client by telling her that her vet had prescribed antifreeze, which is deadly to dogs. The truth is, propylene glycol is not toxic. It is, however, used to help with skin issues. (The toxic antifreeze ingredient is ethylene glycol.)

More Mistakes
Many respondents to the OVMA survey said retail pharmacists have changed their prescribed insulin. Glargine is an expensive type of insulin. A pharmacist switched it for NPH because it was less expensive. The pharmacist believed that the two products were interchangeable. However, NPH is less effective in diabetic cats.
The OVMA reports, “In one example, the patient suffered serious complications, i.e., diabetic ketoacidosis. In other instances, the patients received [a dosage that was too low] until a recheck with their veterinarians caught the problem.”
Pharmacists may simply just not understand something on the veterinarian’s prescription, or why the dose seems extremely high for a 100-pound dog as compared to an average human dosage, or really be trying to save you money, and that is all fine. However, a pharmacist legally and professionally is obligated to critically read prescriptions and ask questions when they have concerns. So they should contact the vet before making any changes on their own.
You should never hesitate to ask pharmacists to contact your vet when they are telling you they would like to change something. They may have your interest or your pet’s in mind, but this may end up being a painful mistake.
Of course, the safest solution may be to get medications from your vet. Chances are, it will not be more expensive than at a pharmacy, but you will get what your pet truly needs. By not going to the local pharmacy, you will also save time and gas money.
And this is clearly the first step to getting better and healthier.
One could hope that vets and pharmacists would work together to help cats and dogs get healthier. Unfortunately, after being “burned” a few times, vets can become leery of encouraging clients to pick up prescriptions at the pharmacy.
What You Can Do
What should you do if you still prefer to get drugs from the pharmacy?
- Compare the label on the vial to the written prescription.
- Ask the pharmacist, or the pharmacy assistant, to help you decipher the probably difficult-to-read-handwriting on the prescription.
- Check the name of the medication.
- Check the frequency.
- And check the dosage.
This article is not meant to scare you, but to inform you of possible problems. Ultimately, we want your pet to be safe and happy.
This pet health content was written by a veterinarian, Dr. Phil Zeltzman, DVM, DACVS, CVJ. Kelly Serfas, a certified veterinary technician in Bethlehem, Pennsylvania, contributed. This article was reviewed for accuracy by Dr. Pippa Elliott, BVMS, MRCVS, and was last updated Feb. 4, 2019.