These drugs can save your dog's life in some cases, but there's a right way to use them.
dog being held by a vet
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There's a pretty good chance your dog will need to take antibiotics at some point, just like you've probably needed them for yourself. Antibiotics can save lives by destroying infection-causing bacteria, and humans have been using natural forms of them since ancient times. Since their scientific discovery and development during the 19th and 20th centuries, antibiotics have become a staple of modern medicine—both human and veterinary.

There are several different classes of antibiotics available for use in animals, including penicillins, cephalosporins, cephamycins, aminoglycosides, quinolones, sulfonamides, tetracyclines, and macrolides. The type of antibiotic used to treat a cut on the paw is not necessarily the same one needed to treat a UTI. Your veterinarian will choose the best class and type of antibiotic for the type of infection your dog has. The following are some of the more common antibiotics used in veterinary medicine:

  • Amikacin
  • Amoxicillin
  • Amoxicillin/Clavulanate (Clavamox)
  • Azithromycin
  • Bacitracin/neomycin/polymyxin (triple antibiotic for topical or ophthalmic use)
  • Cephalexin
  • Chloramphenicol
  • Clindamycin
  • Doxycycline
  • Enrofloxacin (Baytril)
  • Gentamicin
  • Marbofloxacin
  • Metronidazole (Flagyl)
  • Nitrofurantoin
  • Tetracycline
  • Trimethoprim-sulfamethoxazole
  • Tylosin

What Conditions Are Treated With Antibiotics in Dogs?

An infection can occur in any part of a dog's body, and there are many different species of bacteria that may cause infection. Some of the most common types of infections seen in dogs are:

What Are Potential Side Effects of Antibiotics in Dogs?

Antibiotics can save lives, but they can also cause some side effects. If your vet has prescribed antibiotics for your dog, it's because the benefits of antibiotic therapy outweigh the potential risks. In general, antibiotics may cause the following side effect in dogs:

Contact your vet if your dog is experiencing side effects from antibiotic therapy. Your vet may adjust the dose or switch to a different antibiotic.

There are specific adverse effects that veterinarians keep in mind when prescribing antibiotics:

Microbiome Imbalance

Antibiotics can't distinguish beneficial bacteria from harmful bacteria, so they may disrupt the body's microbiome balance. This can lead to gastrointestinal upset and skin issues like yeast infections. Probiotics may help replace a dog's beneficial bacteria and prevent problems caused by microbiome imbalance. Talk to your veterinarian about the appropriate use of probiotics for your dog.

Antimicrobial Resistance 

While antibiotics are life-saving, they do not treat viruses. Historically, people and pets with viruses were prescribed antibiotics to prevent secondary infections—a practice that is no longer recommended. Antibiotic overuse in both human and veterinary medicine has enabled some bacteria to adapt and evolve into antibiotic-resistant superbugs that don't respond to traditional antibiotic therapy. This can make antibiotic therapy less effective for individual dogs. Even worse, it can pose a public health threat by making it more difficult to treat humans and other animals with diseases caused by antibiotic-resistant bacteria. This is why your vet will only prescribe antibiotics when necessary and at the most appropriate dose based on recommended guidelines.

How to Give a Dog Antibiotics

Antibiotics are often given orally as a tablet, capsule, or liquid. Most are administered once or twice a day, but some require more frequent dosing. In general, it's best to give antibiotics with food to reduce the chance of gastrointestinal side effects. Tablets and capsules can be wrapped in Pill Pockets or treats to make them easier to administer. If you give a pill alone by hand, make sure it goes all the way to the back of the tongue, then gently hold your dog's mouth closed and massage the throat to encourage swallowing. Liquid doses can be dripped directly into the side of the mouth with a syringe or dropper. Liquids can also be mixed with small amounts of food, but make sure your dog eats all of it. Many liquid antibiotics require refrigeration, so check the label for instructions.

Topical antibiotics are generally applied to the source of the infection, such as the skin, ears, or eyes. After applying antibiotic cream or ointment to the skin, make sure your dog cannot lick it off. Not only will this prevent the antibiotic from treating the wound, it can also be toxic. Your dog may need to wear an e-collar (cone) for the duration of treatment. When using topical antibiotics for the ears or eyes, make sure you follow the instructions carefully. Most need to be shaken well before use and some require refrigeration. In addition, ear medications can cause permanent damage if they are applied into the eyes by mistake.

Injectable antibiotics are sometimes used in veterinary facilities during hospitalization, surgery, and various procedures. These are rarely used at home, but your vet will provide detailed instructions if needed.

Antibiotics Dosage for Dogs

Your veterinarian will determine the appropriate antibiotic dosage based on your dog's weight and the condition being treated. If your dog has a history of sensitivity to a certain antibiotic drug, your vet may adjust the dose or choose a different drug to avoid side effects. Be sure to follow your vet's instructions when giving antibiotics to your dog. Do not alter the dose or stop the medication without first speaking with your vet. Adjusting doses or stopping a course of antibiotics early may lead to antibiotic resistance.

Can Dogs Overdose on Antibiotics?

Dogs may overdose on antibiotics if they are given too much by accident or they get into the antibiotic container. Ingestion of excess antibiotics often leads to gastrointestinal effects like vomiting, diarrhea, drooling, and loss of appetite. Some overdoses can lead to central nervous system effects like seizures or tremors.

Contact a professional for advice if your dog gets an overdose of antibiotics. Call your regular vet, a pet emergency center, or a pet poison control service like ASPCA Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661. The veterinarian may advise you to induce vomiting if the overdose happened recently. Either way, your dog will most likely need to see a vet in-person for follow-up testing and treatment.

Antibiotics Drug Interactions and Warnings

Certain medications can interact with some antibiotics. Some combinations will reduce the effectiveness of one or both drugs, but others can lead to toxicity. Tell your vet about all medications and supplements that your dog is on before starting antibiotics. Avoid starting new medications or supplements while your dog is on antibiotics unless your vet are advises you to do so.