Protect Your Pet from Errors with Medicines


Imagine your dog or cat is sick, and you head to the veterinary clinic or animal hospital. The veterinarian prescribes medicine that you hope will make your pet better. But with pets, as with people, medicine errors can happen. In fact, there are many opportunities to make a mistake when a pet is treated with medicines. Errors can happen at the veterinary clinic when prescribing medicines or when dispensing the pet’s medicine. Mistakes can even happen in a pharmacy if prescriptions for pets are filled in the same pharmacies that serve human patients. Or errors can happen at home, when the pet owner gives their pet the medicine. 

Examples of Errors

Errors can start with something as simple as an abbreviation. Commonly used in human and veterinary medicine, medical abbreviations are not universal; nor are the many variations for abbreviated medical terms. As a result, a pharmacist in a human pharmacy may not be familiar with certain veterinary abbreviations. For example, “SID” (once daily), sometimes used in veterinary prescriptions, has been misinterpreted as “BID” (twice daily) and “QID” (four times daily), resulting in pet overdoses.

In addition, the wrong medicine may be dispensed because of look-alike medicine names, labels, or packaging. For example, one veterinarian called a human pharmacy to prescribe Zeniquin (marbofloxacin), an antibiotic, for a dog and asked the pharmacist if it was available in a generic form. The pharmacist misheard the drug name as “Sinequan” and dispensed doxepin, a generic form of Sinequan. Sinequan is used to treat depression and anxiety in humans. The dog owner called the veterinarian 24 hours later stating that the dog was ill. Fortunately, the dog was treated and recovered.

Accidental exposures to some human drugs can be dangerous and can cause fatalities in animals. For example, in recent years, a number of dogs have died after swallowing their owner’s fluorouracil medicine or licking the cream form of the medicine off their owner’s skin where the cream had been applied. Fluorouracil is a chemotherapy medicine used to treat several types of cancer. This medicine is toxic to most animals, but deaths have mostly been reported in dogs. After accidentally swallowing the medicine, the fluorouracil can impair the natural chemical reactions that produce energy and damage the gastrointestinal tract, nervous system, liver, and other vital organs.

One recently reported tragic case involved a 3-month-old dachshund puppy. A man who was receiving fluorouracil intravenously (IV, given through tubing into a vein) at home was lying in his bed awake. The puppy jumped onto the bed and went under the covers. The puppy was under the covers for about 30 minutes when the man noticed that the bed felt wet. He found that the puppy had bitten into his fluorouracil tubing. At first, the puppy did not seem to have any symptoms. But a few hours later, the puppy began vomiting, stopped moving, and eventually died. Today, there are no chemotherapy or IV line protectors available. We are hoping that a bite-proof line will be created so that pet owners will have the option to use “pet-proof” IV lines, thus providing a preventative layer of protection for their pets. 

Another reported case involved a mistake when a human pharmacy typed the instructions on a carton of a Novolin N (insulin NPH) vial (100 units per milliliter [mL]) for a dog. The instructions said to “inject six milliliters under the skin two times a day.” But the instructions should have said to “inject six units under the skin two times a day,” which would have equaled 0.06 mL, not 6 mL. The dog’s owner was given very small insulin syringes to measure out the prescribed dose. But a 6 mL dose would have required many syringes and injections. Fortunately, the dog’s owner thought that maybe an error had been made and went back to the pharmacy, where the instructions were corrected. But had the dog’s owner followed the erroneous instructions and given his dog 6 mL of the insulin—a 100-fold error—it likely would have been lethal.

FDA’s Role in the Safety of Pet Medicines

Just as the US Food and Drug Administration (FDA) monitors errors with medicines that affect people, the agency watches out for mistakes with medicines that may harm pets and other animals. Within the FDA is the Center for Veterinary Medicine (CVM) that, among other things:

• Makes sure a medicine is safe and effective before approving it for companion pets such as dogs, cats, and horses; or for food-producing animals such as cattle, pigs, and chickens
• Monitors the safety and effectiveness of pet and other animal medicines on the market

The CVM does not provide veterinary advice or monitor the practice of veterinary medicine. But it does encourage reports of animal medicine errors, side effects from medicines given to animals, side effects in people exposed to medicines used for animals, product defects, or lack of effectiveness of a medicine. You can report these adverse events to the CVM by filling out an electronic form ( and emailing it to the CVM at: This email address is being protected from spambots. You need JavaScript enabled to view it. , or by calling 1-888-FDA-VETS (1-888-332-8387).

A number of the errors with medicines that occur in the treatment of people are the same as those seen when treating animals. For this reason, the CVM collaborates with the human drug center at FDA to share, learn, and distribute information about the prevention of errors with medicines. For more information about FDA’s role in animal medicine safety, including a YouTube video entitled Medication Errors Happen to Pets Too, visit:

Here’s What You Can Do

There are a number of steps you can take to prevent errors with medicines for your pet. First, before you leave the veterinarian’s office, be sure you know the answers to the following questions:

• What is the name of the medicine?
• What is the medicine supposed to do?
• How much of the medicine should I give each time?
• How should I give the medicine to my pet?
• If the medicine comes with a device or is packaged with a measuring device, how is it used? (Ask your veterinarian or pharmacist, if filling a prescription at your community pharmacy, to show you how to use the device properly.)
• How many times a day should I give the medicine?
• Should I give the medicine before, during, or after meals?
• How should I store the medicine?
• What should I do if I forget to give a dose to my pet?
• Should I finish giving all the medicine, even if my pet seems better?
• Are there reactions I should look for and call you about right away?
• What steps do I follow if my pet accidentally swallows a human or pet medicine?

Next, help your veterinarian keep your pet safe by doing the following:

• Keep a list of all medicines that your pet takes—including over-the-counter products, supplements, and prescription drugs—and bring it with you to the veterinary office
• Discuss any medicines that your pet is allergic to or that have caused problems in the past
• Discuss any serious or chronic health conditions that your pet may have

Also, there are some simple steps you can take at home to avoid errors and ensure pets do not accidentally swallow a medicine:

• Store animal and human medicines out of reach of pets
• Keep pets away from any medical tubing (e.g., IV chemotherapy lines) used in the home
• Ensure pets do not lick the medicine off the skin of the owner, or other family members/visitors if the medicine has been applied to the skin
• Keep pet medicines stored away from human medicines to prevent mix-ups
• Keep your pet’s medicines in their original labeled containers
• Do not share the medicine for one animal with another animal unless directed by a veterinarian
• Do not give human medicines to your pet unless directed by a veterinarian

Finally, we encourage people to report errors, side effects, ineffectiveness, or defects with animal medicines to the CVM. The CVM provides a YouTube video entitled Your Report Matters! How to Report Side Effects or Product Problems with Drugs Used in Animals. The video encourages both veterinarians and animal owners to report adverse events to them. For details on reporting and to watch the video, visit: You can also report errors to ISMP’s Consumer Medication Errors Reporting (ISMP CMERP) by going to:

Created on August 10, 2021

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