Extralabel use of drugs can give veterinarians effective options in treating patients, but there are limitations veterinarians should be aware of when considering extralabel drug use.

Guidelines set out in the Animal Medicinal Drug Use Clarification Act impose certain restrictions on veterinarians who prescribe approved human and animal drugs for use in ways other than stated on the label. Most of these restrictions apply to use in food animals, but some limitations also pertain to horses and small animals.

The AVMA was recently made aware of questions from veterinarians about treating patients with a drug labeled for use in another species, instead of using a similar drug labeled for use in that species.

Specifically, equine practitioners have been inquiring about the legality of treating horses with Previcox (firocoxib), a nonsteroidal anti-inflammatory drug labeled for use in dogs, instead of Equioxx, which contains the same ingredient but is labeled for use in horses. Both are manufactured by Merial.

The subject has appeared on a number of equine message boards, with equine veterinarians reporting that horse owners are requesting Previcox over Equioxx because of the substantial cost difference between the two products.

According to AMDUCA, however, because Equioxx is labeled for use in horses, the canine product cannot legally be used in an extralabel fashion in horses. Read More…