Major Uses

Amoxicillin is a commonly used, broad spectrum antibacterial medication that is used to treat or control both gram-positive and gram-negative bacteria. The drug treats infections by preventing production of the cell wall of bacteria, and it is most effective when the bacterium does not have oxygen to fuel the infection. Amoxicillin treats a variety of infections caused by bacteria, for example, skin and wound infections, urinary or bladder infections, upper respiratory, and teeth infections. A generally safe drug, amoxicillin can be prescribed to most species.

Common Precautions

Although amoxicillin is typically a safe medication, adverse reactions can occur. Vomiting, diarrhea, and loss of appetite are the more commonly seen side effects, but the pet's veterinarian should be contacted if these reactions persist. The medication is safe to give with or without food, but sometimes giving with food can help reduce nausea. Since possible drug interactions can occur, the prescribing veterinarian needs to be aware of all medications, vitamins, and supplements the pet is currently taking. Amoxicillin can also interact with other antibiotics, such as tetracycline and chloramphenicol.

Amoxicillin should not be administered to animals with a known allergy or hypersensitivity to the drug. Signs of an allergic reaction include swelling of the face, scratching, hives, and seizures. Some dogs on amoxicillin for long periods of time had trouble with coordination and difficulty walking. If any of these symptoms occur, the pet's veterinarian, or emergency care, should be sought immediately.


Amoxicillin should be stored in a childproof container, impervious to light. Typically, oral suspension forms are refrigerated, however, it is suggested that the manufacturer storage directions are closely followed.


Amoxicillin is available in tablet form, ranging from 50 mg to 400 mg, as well as in the suspension form. The pet's veterinarian should be consulted before the drug is administered, but a typical dose for dogs and cats is 3 - 10 mg/lb (6.6 - 20 mg/kg) by mouth every 8-12 hours. For horses, the typical dose is 3 - 10 mg/lb (6.6 - 22 mg/kg) every 8-12 hours injected intramuscularly. Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

If a dose is missed it should be taken as soon as possible, unless it is almost time for the next dose. If it is almost time for the next dose, the missed dose can be skipped and the regular dosing schedule should be followed; two doses should not be given at once. The prescribing veterinarian should be contacted if there are any questions or concerns.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.