If your cat's ever been treated for an infection, there's a good chance the vet prescribed amoxicillin. This antibiotic effectively combats a wide range of bacteria, and is relatively inexpensive. Common feline maladies, including abscesses, urinary tract infections, upper respiratory infections and certain gastrointestinal ailments, often respond to amoxicillin. Your vet cultures a tissue sample to ascertain the bacteria involved before prescribing amoxicillin.
Amoxicillin for Cats
Similar to penicillin, amoxicillin can kill both gram-negative and gram-positive bacteria and absorbs better than the earlier drug. It's available for veterinary use in liquid, injectable and tablet forms. Once mixed, the oral suspension must be kept refrigerated and used within two weeks. Besides generic versions, amoxicillin is marketed under the names Amoxi-Tabs, Amoxi-Drops and Robamox. The drug is also commonly prescribed as Clavamox, where it is combined with clavulanate potassium. The combination of these two drugs allows Clavamox to eradicate bacteria resistant to amoxicillin alone.
Amoxicillin is effective against Proteus mirabilis, Staphylococcus aureus, Streptococcus faecalis and E. coli. All of these organisms can invade the skin, respiratory tract, gastrointestinal tract and urinary tract. Amoxicillin is effective against Pasteurella multocida, found in the skin from wounds or abscesses. Clavamox is effective against Bordetella bronchiseptica, various forms of Corynebacterium and Enterobacter, salmonella, Erysipelothrix rhusiopathiae and Klebsiella pneumoniae, among others.
Course of Treatment
Your vet calculates the amoxicillin dosage based on your pet's weight. Typically, your cat receives the drug two or three times daily, for approximately 10 days. Even though you might see considerable improvement in your cat within a few days -- he appears "back to normal" -- it's important to keep giving him the medication for the allotted time. If you stop giving him amoxicillin within the prescribed time frame, he could suffer a relapse. The bacteria in his body could develop resistance to the medication, so he could require a stronger antibiotic with more potential side effects.
Side Effects and Contraindications
Most cats tolerate amoxicillin quite well, with few, if any, side effects. Some cats will develop diarrhea or lose their appetite while on the medication. Less common side effects include drooling and vomiting. Cats sensitive to penicillin shouldn't receive amoxicillin. A cat allergic to the drug might have breathing difficulties. Call your vet if your cat experiences any side effects. Tell your vet about any other medications or supplements you give your cat. Unlike many other drugs, amoxicillin is safe for pregnant and nursing mothers and kittens.