Dear Ruffled Feathers,
When it comes to prescribing medications for animals there are many factors to be considered. Animals can be organized into groups. At Pet Health, we focus on companion animals, such as dogs, cats, and ferrets, which would be considered “pets” only. Veterinarians are not as restricted with companion animals and can generally prescribe medications as deemed appropriate. When treating performance animals, such as sport horses, veterinarians must consider how long certain drugs remain in the body for competition purposes. Food-producing animals must be given special consideration. These animals include cattle, pigs, turkeys, and chickens.
The Animal Medical Drug Use Clarification Act of 1994 (AMDUCA) allows veterinarians to use human or animal medications to meet the needs of their animal patients. However, it limits the use of certain drugs in animals that are used for food or providing food for humans. Even if your chicken is a “pet,” it would still be categorized as a food-producing animal. Some drugs remain in an animal’s body for extended periods of time and may be passed into meat, milk, or eggs. In addition, overuse of antibiotics in animals can contribute to bacteria that are resistant to antibiotics. These bacteria may be transferred to humans and reduce the effectiveness of antibiotics for treating human disease.
So, to use your case as an example, enrofloxacin belongs to a class of antibiotics, fluoroquinolones, which was banned for use in chickens (and other food-producing animals) by the FDA and is listed by AMDUCA as forbidden for use in these animals. Because a chicken given enrofloxacin may lay eggs (or provide meat) that potentially contain bacteria resistant to this antibiotic, a different antibiotic should be chosen to treat your chicken. I hope your chicken feels better soon!