Written By hannah hollinger
Published: 08/07/2020Updated: 08/30/2021
Gentamicin for Dogs | Wag!

Gentamicin is an antibiotic commonly used to treat ear or eye infections in humans, dogs, and other small animals. Gentamicin belongs to a class of antibiotics known as aminoglycosides, which includes amikacin and neomycin. 

Gentamicin is only available through prescription and goes by several brand names, including Gentocin® and Garamycin®. It’s also an ingredient in many other drugs containing antifungal properties and steroids, such as Vetromax® and Otibiotic®. While gentamicin is commonly used in veterinary medicine, complications can arise from improper application and reactions. Read on to find out more about your dog and gentamicin.


Gentamicin can be administered in several ways, including as an ointment, in a liquid solution, or intravenously in a veterinary setting. Depending on the severity of the infection and the treatment method, the amount of gentamicin you should give your dog may vary. Always follow your vet's instructions carefully when giving gentamicin to your dog. You should wait an hour before administering gentamicin if you are currently giving your dog a different aminoglycoside or a medicine that contains fluoroquinolone.


Gentamicin is very effective in fighting a wide array of different bacteria. It can treat bacteria found in several parts of the body, including the ear canals, sinuses, bladder, and bloodstream. It can also help prevent infections in wounds and help treat pneumonia. 

Gentamicin targets the proteins in bacteria and stops them from growing. Like all antibiotics, your dog should complete their full treatment cycle as prescribed by your vet. You shouldn't stop giving your dog gentamicin midway through a course of antibiotics, as the infection may return.

Side effects

Gentamicin causes a few mild side effects. Common side effects include:

High doses of gentamicin can also cause loss of balance, loss of hearing, and paralysis. Side effects and adverse reactions to gentamicin are rarer when applied topically, as the drug is absorbed at a lower rate. If you notice these symptoms, whether severe or mild, stop giving your dog this medication and immediately contact your vet. 


Drug interactions

While there are no known drug interactions when using gentamicin as an ointment, you should always tell your vet about any other medication your dog is taking. You should also tell your vet if you are giving your dog any additional supplements or vitamins, as they may affect treatment.

Allergic reactions and sensitivity

It's possible for your dog to be allergic to gentamicin and other aminoglycosides. If you notice your dog is having an adverse reaction to this drug, contact your vet immediately. Gentamicin has been known to cause kidney damage in rare cases and should be used with caution in dogs with kidney disease. 

You should make sure your dog stays well hydrated when administering gentamicin. Use caution when giving your dog gentamicin if your dog a muscle or neurological disorder. You should not administer gentamicin to dogs that are pregnant or nursing. 

Frequently asked questions

What should I do if I forget to give my dog gentamicin?

If you've forgotten to give your dog a dose of gentamicin, give it to them as soon as possible. However, if it's close to when your dog is due their next dose, skip the dose you missed. Do not give your dog an extra dose of gentamicin, as this could cause serious side effects. 

Will my dog need to be monitored while taking gentamicin?

Your vet may want to monitor liver enzyme levels in your dog, especially if they have a heart, liver, or kidney disease. If enzyme levels are higher than normal, this can indicate kidney damage, which will mean a change in treatment. 

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