Over the Counter Antibiotics for Dogs

Cuteness may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.

Certain types of supplements and antibiotics for animals are available at pet stores or online without a prescription. Some topical antibiotic ointments for humans could possibly be used safely on dogs. But it's always best to get over-the-counter (OTC) antibiotics made specifically for dogs so you don't end up making your canine sicker. For example, Neosporin, a topical antibiotic for humans, has two ingredients that have been approved for use in pets, but one ingredient is a problem for dogs and will negatively impact your pet's health and wellness.


Image Credit: Janie Airey/Lifesize/Getty Images

Topical dog antibiotics aren't always safe

You might think there's nothing wrong with rubbing a little topical antibiotic ointment on your pet's wounds or scrapes. Topical antibiotics such as bacitracin and polymyxin B — two of the active ingredients in the topical salve Neosporin — are generally considered safe for use in pets. However, the third ingredient, neomycin, has been associated with hearing loss in dogs.


Video of the Day

Furthermore, the lubricant used to deliver the medications can also cause digestive upset if your dog happens to reach the spot and lick the Neosporin or other topical ointments, potentially resulting in vomiting or diarrhea. Also, topical antibiotics containing zinc are dangerous to your dog. Avoid over-the-counter antibiotics for dogs such as bacitracin zinc or other zinc products, like diaper rash ointments.


Over-the-counter meds without a veterinarian

Although systemic veterinary antibiotics are available without a prescription in feed stores and pet stores for livestock and fish, you usually need a veterinarian's prescription for dogs and cats even if you buy them online. Should you choose to buy dog antibiotics without a veterinary prescription from an online source, you have no guarantee of the product's effectiveness or that it is correct for your dog's illness.


It's easy to think that a round of penicillin will take care of just about anything that ails your pet. However, the antibiotic would be inappropriate, for example, for certain types of staph infection. Some staph produce beta-lactamase, which is an enzyme that inhibits the effective action of penicillin by hydrolyzing it.


Note that due to antibiotic resistance, there are prescription antibiotics that contain beta-lactamase inhibitors, which can be used to treat some staph infections when combined with a penicillin, such as Clavamox. However, due to growing antibiotic resistance, some staph don't respond to these treatments either.


Image Credit: Nicolas Jooris-Ancion/iStock/GettyImages

Selecting dog antibiotics is challenging

To effectively choose an antibiotic for your dog, pet parents need to be able to discern what type of bacteria is making their dog ill. Each bacterial infection requires antibiotic treatment for a specific length of time. For instance, treating an infection that would require eight weeks of antibiotics for fewer weeks or using the wrong type of antibiotic for the infection could put your pet's health at serious risk.



Side effects of antibiotics usually include diarrhea and vomiting. Not only could you end up with unnecessary messes to clean up but your dog could also end up worse off due to dehydration.

Can you buy veterinary antibiotics OTC?

No, you can't buy over-the-counter veterinary antibiotics for dogs.‌ It's true that penicillin is one example of an antibiotic that's available over the counter at feed stores for species such as cattle, swine, and fish. However, the Food and Drug Administration (FDA) hasn't approved these products — or any other over-the-counter antibiotics that are injected or ingested — for use in veterinary medicine for companion animals, such as dogs.


Because directions for safe and effective use of penicillin or other antibiotics by a layperson can't be written to apply to all circumstances, the FDA requires antibiotics for dogs to come with a prescription. This enables the veterinarian to write specific directions for each animal based on their individual needs, such as the type of infection, duration of administering the drug, weight, species, and other factors.

Image Credit: fotografixx/E+/GettyImages

Livestock antibiotics and dogs

An antibiotic that works on cattle, swine, or fish won't necessarily work for your dog, even if it appears to be a name that you're familiar with, such as "penicillin." Formulations for each species are geared toward effectiveness and bioavailability in that particular type of animal's system. For example, a formulation for an herbivore or ruminant won't work the same in a meat-eating, nonruminant animal.

Therefore, don't use fish or livestock antibiotics on your dog. To do so could create bacterial resistance to treatment in the future, delay your pet's recovery, or even endanger their life.

The bottom line

If your pet has an internal infection, ear infection, skin infection, or rash, it is best to get a prescription for the appropriate antibiotics from a veterinarian. Topical antibiotics intended for humans, such as Neosporin, contain ingredients that can hurt dogs. Also, over-the-counter antibiotics and those purchased online might not come with the correct dosing instructions for your pet, including medication intended for livestock.



Report an Issue

screenshot of the current page

Screenshot loading...