Today on Texas Vet News I am going to talk about a regulation your veterinarian must abide by when administering medications for your animals. Many of the medications veterinarians use are labelled for only one species. Although veterinarians may use different drugs in unapproved species, there are specific regulations we must follow. Getting a drug approved for a particular species is expensive and getting approval for more than one species is even more expensive. It is important to realize that the actual cost of the chemical in the drug is only a small part of the cost because of all the testing required by the FDA. I am not saying this testing is not important, but it does increase the cost of the drug. In most cases, testing drugs for horses is more expensive than testing for dogs and cats due to the expense of keeping a herd of horses for testing.
The reason I discuss this background specifically is to talk about a drug that is approved for both dogs and horses called firocoxib. The drug has different forms approved for horses and dogs. Firocoxib is a non-steroidal anti-inflammatory drug used for pain and inflammation due to arthritis. The approved drug for dogs is called Previcox and the approved drug for horses is called Equioxx. Equioxx, the horse form, is much more expensive than the dog form and many people want to use the dog form for their horses. However, it is illegal to do so because of lack of testing and approval. It is permissible to use an approved human drug in an animal if it is less expensive, even if there is an animal drug available. However, you cannot use an approved animal drug from one species in another species just because it is less expensive.