UNDERSTANDING ANIMAL ANTIBIOTICS

Why & When Veterinarians Use Animal Antibiotics

Just like in people, antibiotics are used in animals to treat, control, and prevent diseases. Animals are vulnerable to some of the same bacterial infections as people, such as pneumonia and skin infections, and these diseases can be treated with antibiotics. Additionally, antibiotics are often given to animals to treat diseases spread by ticks. Some of these diseases can be chronic and cause severe illness, and they can also be passed from animals to humans, so administering appropriate medicine in animals can stop the spread of disease across species.

Young animals have immature immune systems, which makes them more likely to succumb to illness. And even mature animals are at increased risk infection during times of stress, such as transportation, change in location, rapid change or extreme weather, and following surgery. Hence, farm animals may require antibiotics to treat existing infections or to control the spread of a bacterial disease within a group of animals.

Farmers and veterinarians work together to prevent these occurrences and create and maintain healthy conditions for their flocks and herds. They work constantly to improve biosecurity, vaccinate, and adopt other management techniques to maintain a healthy herd. Despite these efforts, disease threats still occur, and veterinarians need access to antibiotics to address illnesses and protect the welfare of the individual and the herd.

Animal Antibiotics Administration

Antibiotics for animals can be administered in the same way as for people: orally or via an injection. Though unlike humans, there are practical considerations when administering antibiotics to large groups of farm animals.

When disease affects a large group of animals, group treatment calls for administering antibiotics through either feed or water to ensure the animals are receiving the medicine. The veterinarian uses information about the farm, size and weight of the animals, and feeding regime to determine the amount of medicated feed or water needed for proper dosage. They then ensure animals get the right dose at the right time and frequency without causing the animal unnecessary stress.

Types of Antibiotics

There are several ‘classes’ of antibiotics, with penicillins, tetracyclines, and macrolides being the most common in animal use. Some are effective against a wide range of bacteria (broad spectrum), while others may target only a small set of bacteria (narrow spectrum). Some types can be used in both people and animals, while others are only useful and approved in either animals or people.

As defined by the FDA, the term ‘medically important’ can refer to antibiotic classes important to human medicine. Importantly, many antibiotics important to human medicine are not used in animals. Additionally, there are other antibiotic classes defined by OIE that are used in animal medicine (e.g., ionophores) that are neither used for nor important to human medicine.

Veterinarians & Animal Antibiotics

All medically important antibiotics used in animal feed and water are under the control of licensed veterinarians, who play a critical role in antibiotic management. Medically important antibiotics used in feed and water for food animals all have two significant restrictions:

They can only be used under the direction of a licensed veterinarian using a Veterinary Feed Directive (VFD), which is a form filled out by a veterinarian that provides directions about mixing antibiotics into feed at the proper dose.
Antibiotics used in this manner may only be used according to the FDA-approved directions on the label.

About Animal Health Institute

The Animal Health Institute (AHI) represents the companies that develop and produce animal medicines. Our industry is a global leader whose products improve the health of nearly 10 billion companion and food-producing animals in the U.S., which results in significant economic and social benefits for Americans.