Amoxicillin for Dogs and Cats

In This Article

Overview

PetMD’s medications content is written and reviewed by veterinary professionals to answer common questions about how medications work, their side effects, and what species they are prescribed for. This content should not replace advice from your veterinarian. 

Key Takeaways

  • Amoxicillin is a penicillin antibiotic used in dogs and cats to help treat bacterial infections.
  • It is FDA-approved for dogs and cats; compounded versions are not FDA-approved and are prepared when a different strength or dosage form is needed.
  • Amoxicillin works by stopping the growth of bacteria in the body and weakening infections.
  • It may be given with or without food, though food may help reduce stomach upset. Shake liquid suspensions well and refrigerate after mixing.

What Is Amoxicillin Used for in Dogs and Cats?

Amoxicillin​ is an FDA-approved penicillin antibiotic medication commonly used in dogs and cats to help treat a wide variety of certain bacterial infections, including:  

In certain situations, amoxicillin may be prescribed by veterinarians for extra-label uses. The term extra-label or off-label treatment means that a medication is used in a way that is not specified on the medication label.  

Conditions amoxicillin is used to treat in dogs and cats extra-label include: 

Amoxicillin comes in liquids and tablets

Compounded Amoxicillin 

In certain circumstances, your veterinarian may recommend a compounded formulation of amoxicillin.  

Compounded medications may be prescribed if there’s a specific reason your pet’s health can’t be managed by an FDA-approved drug, such as if:  

  • Your pet has trouble taking the commercially available form  

  • The required dosage strength is not available  

  • The pet is allergic to an ingredient in the FDA-approved medication 

Compounded medications are not FDA-approved. They are prepared by a veterinarian or licensed pharmacist on an individual basis to meet a pet’s specific needs. 

Amoxicillin Considerations for Dogs and Cats

Your dog or cat should avoid this medication if they’ve ever had an allergic reaction to penicillin or amoxicillin.  

How Does Amoxicillin Work in Dogs and Cats?

Amoxicillin is classified as a penicillin antibiotic.  

It works to stop bacteria from building their own cell walls as they grow. The walls of the bacteria become weakened, causing the bacteria to die.  

How Do You Give Amoxicillin to Dogs and Cats?

Follow the directions on the ​drug label​ or as provided by your veterinarian.  

  • Amoxicillin can be given with or without food, but giving it with a meal can help prevent digestive upset.  

  • For the oral suspension of amoxicillin, follow the mixing directions closely and note the exact amount of water that should be mixed with the powder to create the suspension. Shake the bottle of amoxicillin suspension well before administering a dose to your pet. 

What Happens If You Miss a Dose of Amoxicillin? 

Speak with your veterinarian about what to do if a dose is missed.  

Generally, your vet may instruct you to give it when you remember, or if it is almost time for your pet’s next dose, to skip the missed dose and resume your normal dosing schedule. 

Do not give extra or double doses. 

What Are the Side Effects of Amoxicillin in Dogs and Cats?

Amoxicillin can cause gastrointestinal side effects in dogs and cats. Look out for symptoms such as:   

Penicillin allergies in dogs and cats are rare but can happen. Amoxicillin is closely related to penicillin, so allergic reactions can occur and may include: 

This medication should not be given to pets who have a history of allergic reaction to penicillin. 

Human Side Effects 

Humans should never take medication prescribed for pets, and pets should not be given medication prescribed for humans. Dosages often differ significantly. 

If you accidentally ingest a pet medication, seek medical attention or call Poison Control at 800-222-1222. 

Monitoring Your Pet 

No specific monitoring is required for this medication, but your veterinarian may recommend routine testing depending on your pet’s individual needs, other medications that may be prescribed, and/or the issue that initially caused your pet to be placed on this medication. 

When Should You Call Your Veterinarian? 

Call your veterinarian if you see any of the following, or if you have additional questions or concerns about the use of amoxicillin: 

  • Severe side effects occur  

  • Your pet’s condition worsens or does not improve  

  • You suspect an overdose 

What Happens If a Dog or Cat Overdoses on Amoxicillin?

An overdose of amoxicillin is unlikely to cause toxicity​ in dogs and cats​. However, amoxicillin overdoses may cause: 

  • Vomiting 

  • Diarrhea 

If you suspect an overdose, seek emergency veterinary care or contact an animal poison control center. Consultation fees may apply. 

How Should Amoxicillin Be Stored for Dogs and Cats?

Keep the following storage tips in mind for this medication:   

  • Amoxicillin tablets and the dried powder should not be stored at temperatures above 77 F (25 C). 

  • Once mixed, amoxicillin suspension should preferably be stored in a refrigerator and discarded after 14 days. 

  • Keep the container tightly closed to protect from moisture and light.  

  • Keep out of reach of children and pets. 

  • Always confirm storage requirements by reading the prescription label. 

Amoxicillin for Dogs and Cats FAQs

Is amoxicillin safe for dogs and cats?

Yes, amoxicillin is generally regarded as safe for use in most dogs and cats. It tends to have few side effects.  

Can I give my dog or cat amoxicillin prescribed for humans?

No. You should only give your dog or cat medication that your vet prescribed specifically for that animal.  

Is human amoxicillin the same as amoxicillin for dogs and cats?

Not exactly. The active ingredient in amoxicillin for both humans and pets is the same, but there are differences in dosages, concentrations, and formulations. It’s not safe for dogs or cats to take medications not prescribed by their veterinarian.  

No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content is sourced from public references or the manufacturer. 


Stephanie Howe, DVM

WRITTEN BY

Stephanie Howe, DVM

Veterinarian

Dr. Stephanie Howe graduated from the University of Florida College of Veterinary Medicine in 2011, after receiving a Bachelor of Science...


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