Imagine waking up in the morning and finding your beloved pet on the floor convulsing, motionless or dead.

Now stop imagining, because this was the real-life nightmare this spring for horse trainers in both Lexington, Kentucky and Ocala, Florida when they found their horses experiencing seizures and thrashing in their stalls. In total, more than a dozen horses died or were severely injured – in some cases, paralyzed.

The cause of these horrific scenes – illegally compounded medicines.


These horses were prescribed illegal drug concoctions that contained unsafe levels of pyrimethamine. By one account 25 times the amount it was supposed to contain. A deadly overdose for innocent animals.

There is legal and appropriate animal drug compounding.  All legally compounded product starts with an FDA-approved product.  The product may then be modified by a trained pharmacist on the order of a veterinarian to treat the medical needs of an individual or group of animals such as adding flavorings, or turning tablets into an oral liquid for easier administration.

But some animal drug compounding pharmacies go far beyond those parameters – with deadly results.  They mass produce and market drugs that attempt to mimic FDA-approved products, often using untested bulk active ingredients, imported from countries that may not enforce the strict controls on drug manufacturing that FDA requires for approved products. These copies carry a cheaper price tag than approved drugs, but none of the consumer protection.

Why does this black market exist? It’s both expensive and time-consuming to take a drug through the FDA approval process. For animal drugs, this can take up to 10 years and cost up to $100 million.  But it is a process that protects consumers and their animals – by ensuring that the approved drug is both safe and effective at the labeled dose.

FDA permits a limited amount of necessary compounding from bulk ingredients in order to make sure medical needs can be met when there is no approved drug.  But these compounding pharmacies have taken the proverbial inch and run for murderous miles.  Despite their attempts to muddy the waters with lawsuits and rhetoric, the law is clear: FDA and three federal appeals courts have ruled that compounding animal drugs from bulk substances is illegal. Period.

Illegally compounded animal drugs have caused harm to more than just horses. One university veterinary hospital has reported that dogs and cats are brought in for medical care because their medicines aren’t working, only to find they were being treated with illegally compounded drugs.  The literature is full of reports showing these compounded drugs contain far more or far less than the amount of advertised active ingredient.  This is not acceptable.

As a former FDA Associate Commissioner (and a current dog owner), I know the agency has rigorous enforcement authority.  Pharmacies that engage in illegal manufacturing cannot be allowed to ignore the law and put animal health at risk in the name of selling a cheaper product. 

For several approved animal drugs, FDA has sent warning letters to these pharmacies, but often they were simply ignored and the illegal practices continued.  Unfortunately there has been little to no follow up by the agency. The FDA must do more and commit to strong and sustained enforcement to protect animal health.

What can you do? It’s frightening to think a drug given to your pet might not carry the guarantee of safety and effectiveness that comes with FDA approval.  The first step is to talk to your veterinarian about best treatment options for your pet.  Ask if the drug being prescribed is FDA-approved.  If there’s no approved drug and compounding is necessary, make sure the pharmacist preparing the compound has the credentials and license to do it safely and legally. Why that might sound obvious it is the only – and best – way to ensure the prescribed drug is what is best for your pet. If you have concerns about a pharmacy, check with your state Board of Pharmacy.  At the same time, FDA must do its job of protecting our pets and animals by more regularly and aggressively enforcing the law and regulations.    

Pitts, a former FDA associate commissioner, is president of the Center for Medicine in the Public Interest and a member of the Animal Health Institute’s Board of Scientific Advisors.