How Can Animals Become Resistant to Antibiotics?

Antibiotic resistance is a serious public health threat, and animals are just as susceptible to developing antibiotic resistance as humans. When infections become resistant to antibiotics, the infections are more difficult to treat, requiring higher doses of antibiotics or stronger antibiotics with more serious side effects. In rare cases, a severely resistant infection may be rendered untreatable by antibiotic resistance.

  1. How Antibiotics Work

    • Antibiotics use a variety of mechanisms to kill bacterial infections. Some interfere with the bacteria's ability to reproduce, allowing the body's natural immunity to work with the antibiotics, while other antibiotic medications kill bacteria. Antibiotics typically take several days or even weeks to kill bacteria, and bacteria continues to exist in the body even after the animal's condition begins to improve, according to the textbook "Biology: Life on Earth with Physiology."

    Antibiotic Resistance

    • Antibiotic resistance is, technically speaking, something the bacteria develops, not the animal. It can happen on an individual or large-scale level. Antibiotic resistance within a single animal occurs when the bacteria multiplies and evolves within the animal to resist the antibiotic. If the animal passes the new, slightly altered infection to another animal, then the other animal will become infected with a resistant strain. Neither the original animal nor the new animal will be able to fight off the infection with the antibiotic to which the infection is resistant.

    Prevention of Resistance

    • The most important step pet owners can take to prevent antibiotic resistance is to give their pets the full course of any antibiotics prescribed by a veterinarian. When animals stop taking antibiotics too early, the infection has time to reproduce and develop immunity. You should also avoid giving your pets antibiotics unless told to do so by a veterinarian. Make sure your veterinarian prescribes antibiotics only for bacterial infections, and ask your vet to choose the narrowest-spectrum antibiotic possible for your pet's particular infection.

    Treating Resistant Infections

    • In most cases, a resistant infection will require only a different and perhaps stronger antibiotic to treat the infection. However, some infections have spread between many animals and have had time to become severely resistant. In these cases, your veterinarian may provide supportive care, such as intravenous fluids, to your pet in the hope that her own body will fight off the infection when properly supported. If your pet continues to worsen after several days of antibiotic therapy, contact your veterinarian immediately.