Amoxicillin vs. Clavamox for Cats

Clavamox and amoxicillin are similar, but not the same.
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Amoxicillin and Clavamox are antibiotics that are part of the penicillin family. Like other antibiotics, they're used to treat infections caused by bacteria but are ineffective against viruses. If Frisky has an infection your vet will determine which antibiotic will be most effective in her treatment.

Using Antibiotics in Cats

Penicillin was the original antibiotic used in medicine and forms of it are still widely used in people and animals. Cats and dogs suffering from a variety of infections, including bladder, respiratory and skin infections, as well as abscesses and infected wounds, all benefit from penicillin. If Frisky is suffering from some form of infection, chances are your vet will prescribe amoxicillin or Clavamox, which are two of the most commonly prescribed antibiotics for cats.


Amoxicillin is a form of penicillin that is able to resist stomach acid; it kills bacteria by preventing them from building a proper cell wall that they need to grow. Vets often prescribe amoxicillin to prevent or treat bladder and upper respiratory infections, as well as cuts and wounds and infections in the mouth. It can be administered to Frisky by your vet as an injection, or you can give it to her orally in pill or liquid form. Amoxicillin has side effects, including diarrhea, vomiting or nausea, loss of appetite, drooling or an allergic reaction to the drug, which can result in hives or labored breathing. Giving amoxicillin with food sometimes minimizes the side effects your cat may experience. It can also react with other drugs such as antacids, so be sure to keep your vet up to date on any medication Frisky may be taking.


Clavamox also belongs to the penicillin family and contains amoxicillin and clavulanate, also known as clavulanic acid. Clavulanate makes Clavamox more effective in fighting bacteria than amoxicillin alone—it's more effective against a wider variety of bacteria. If Frisky has a soft tissue or dental-related infection or a urinary tract infection (in her kidneys or bladder), your vet may decide that Clavamox will be the most effective antibiotic. Potential side effects and drug reactions are the same as for amoxicillin.

Using Antibiotics

If your vet has prescribed antibiotics for Frisky, it's important that she take all of the medicine as prescribed. She may appear to feel better, but cutting her treatment short can mean the return of her problems. If she's having a strong reaction to the medicine, such as nausea or diarrhea, or appears to be allergic, contact your vet to see if a different antibiotic will work or if her dose should be adjusted.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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