ChewyHealth / Wellness

Understanding Antibiotics for Dogs

Antibiotic is the term for medicine that is used to stop bacterial infections. Antibiotics stop infections by inhibiting bacteria from replicating themselves or by killing bacteria outright.

Veterinarians prescribe antibiotics for dogs in the same way that your human doctor would prescribe antibiotics for you—to cure bacterial infections anywhere in the body. Learn about the dog antibiotics and their uses for our canine companions.

How do Antibiotics for Dogs Work?

Antibiotics recognize, target and kill bacterial cells while leaving healthy cells alone. That discriminating ability is due to distinct differences between healthy cells and bacterial cells.

For example, bacterial cells have a cell wall, but human cells don’t. Bactericidal antibiotics kill bacteria by targeting their cell wall.

Bacteriostatic antibiotics work differently. Because bacterial cells have different equipment than human cells that they use to replicate and repair themselves, bacteriostatic antibiotics specifically target the replicating equipment in bacteria and stop their growth, dead in their tracks.

Antibiotics can be administered orally, topically, intravenously, injected with a needle under the skin or injected directly into an infected area.

Why Use Prescription Pet Antibiotics?

A veterinarian will prescribe antibiotics when a dog has an active bacterial infection in any organ or to prevent a bacterial infection from occurring after bite wounds, lacerations or surgery. For example, if your dog has orthopedic surgery that requires an implant, such as a plate or pin, then the surgeon will prescribe dog antibiotics to prevent infection around the implant.

Any part of a pup’s body can become infected with bacteria, and if that happens, the appropriate dog antibiotic is prescribed. Some parts of the body, like the skin or mouth, are easy to treat because they are easy to reach. Other parts of the body, such as inside the skull or brain, the prostate or a bone, require different antibiotics, different dosages or different routes of administration to get the antibiotic to where it is needed at the right concentration to stop the infection.

Dog Antibiotics and Their Functions

One of the most common dog antibiotics is penicillin and its derivatives (amoxicillin, ampicillin, etc.). Penicillins are bactericidal antibiotics—they stop infections by killing bacteria.

Metronidazole for dogs disrupts DNA in both bacteria and some intestinal parasites, making it a common drug prescribed for diarrhea in dogs. Enrofloxacin (drug trade name is Baytril) and doxycycline for dogs are bacteriostatic—they both work by attacking the cellular replicating equipment within bacteria.

What Are the Risks of Dog Antibiotics?

Antibiotics for dogs are wonderful life-saving drugs, but they must be used correctly under the supervision of a veterinarian to ensure safe and responsible prescription. Some antibiotics have adverse side effects and should not be prescribed to dogs with certain medical conditions.

For example, aminoglycoside antibiotics can damage the kidneys and can cause hearing loss. Enrofloxacin can induce seizures in dogs with epilepsy, and tetracycline antibiotics can negatively impact normal teeth and bone formation in young pups.

One of the greatest risks of using pet antibiotics is drug resistance. Antibiotics cure bacterial infections, but what happens when they stop working? For only being single-celled organisms, bacteria are really smart, and they rapidly are evolving ways to become resistant to antibiotics.

Antibiotic-resistant bacteria are caused by overuse and misuse of antibiotics. In humans, up to half of antibiotic use is unnecessary or inappropriate, according to the Center for Disease Control and Prevention. In our four-legged friends, veterinarians are most concerned with drug-resistant bacteria in skin infections, surgical site infections and urinary tract infections.

As more antibiotics become powerless, veterinarians have increasingly limited treatment options, leaving them having to use “the big guns,” expensive antibiotics that often have negative side effects. Not only that, but dogs who harbor drug-resistant bacteria may become a human health risk to debilitated pet parents with compromised immune function, such as organ transplant recipients, people with HIV or AIDS, the very old or the very young.

If we are not careful and misuse these precious drugs, they will lose their effectiveness. Antimicrobial stewardship is a hot topic in veterinary medicine these days, as we strive to best manage our resources, for our health and the health of our beloved pets.

In the past 100 years, antibiotics have revolutionized how we treat and manage bacterial infections. When prescribed correctly, antibiotics cure infections, speed healing and save lives.


Sarah Wooten bio

Featured Image: Via iStock/shironosov

Share: