Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Amoxicillin for Cats: Our Vet Explains Uses, Doses & Side Effects

Share

Amoxicillin Amox antibiotic pill tablet close up

Amoxicillin is an antibiotic that is prescribed to cats for various infections (from skin infections to UTIs and pneumonia). It has a broad spectrum of action against a very large range of gram-positive bacteria, including Streptococcus and some strains of Staphylococcus. It’s not considered effective against most gram-negative bacteria.

This medicine is only available with a prescription. Amoxicillin should not be used in combination with certain drugs and should be avoided in cats that are allergic to it. It is usually tolerated well by most cats; however, some cats might experience side effects, such as diarrhea or vomiting. In rare instances, more severe reactions might occur.

divider 2 cats

What Is Amoxicillin?

Amoxicillin is a beta-lactam antibiotic that is effective against several species of gram-positive bacteria and a few species of gram-negative bacteria, such as:

  • Staphylococcus spp. (some strains)
  • Streptococcus spp.
  • Proteus mirabilis
  • Pasteurella multocida

Due to its relatively low efficacy against gram-negative bacteria, it is sometimes combined with other medications to achieve a broader spectrum of antimicrobial activity.

Amoxicillin for cats is used for various bacterial infections, such as respiratory, skin, gastrointestinal, or urinary tract infections. Amoxicillin is available under different brand names, such as:

  • Amoxil®
  • Amoxi-Tabs®
  • Amoxi-Drop®
  • Bimox®
  • Moxatag®
  • Novamoxin®
Amoxicillin white medical pills and tablets spilling out of a drug bottle
Photo Credit: luchschenF, Shutterstock

How Is Amoxicillin Given?

Important

Never attempt to self-prescribe Amoxicillin for your cat. You should only administer this drug for your cat at a veterinarian’s discretion and instructions.

Amoxicillin is available in the form of tablets, capsules, powder for oral suspension, or drops.

The medicine should be administered for the entire period recommended by the veterinarian. You should not stop the administration unless gastrointestinal disorders, lethargy, breathing with difficulty, or swelling of the face occur, and in these situations, you must contact the vet.

Once you start giving amoxicillin to your cat with the vet’s instruction, you should see improvements within a few days (depending on your cat’s response to the treatment).

Amoxicillin is used for a number of different types of ailments and diseases (ranging from skin abscesses to some urinary tract infections). It is also sometimes prescribed in combination with other drugs, and therefore, there is no one dose that works for all cats. The veterinarian will determine a dose and duration of treatment based on your cat’s medical needs.

Amoxicillin is available in the form of tablets, capsules, powder for oral suspension, or drops. Although it can be administered with or without food, it is recommended to give it to your pet after a meal because it can disturb the digestive tract, and vomiting may occur.

The medicine should be administered for the entire period recommended by the veterinarian. Do not stop the administration unless gastrointestinal disorders, lethargy, breathing with difficulty, or swelling of the face occur. In these situations, you must contact the vet immediately.

The liquid forms should be measured carefully and shaken well before administration. Once you start giving amoxicillin to your cat, you should see improvements within a few days. Depending on the product or vet’s recommendations, the usual dose of amoxicillin for cats is 5–10 mg/lb once or twice a day.

In the case of skin abscesses, amoxicillin will be administered for 5–7 days or 2 days after all clinical signs have disappeared. In the case of urinary infections, treatment with amoxicillin lasts 10–14 days on average, but you should not administer it for more than 30 days.

If you are concerned about the health and well-being of your pet, seek veterinary advice for the best course of action.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

divider 3 paws

What Happens if You Miss a Dose?

In case you missed a dose, do not give your cat two doses at once. Wait until the next scheduled dose if you are closer to that, or give your cat the medicine when you remember and then return to their usual dosing schedule.

man holding a cat in a waiting room at vet clinic
Photo Credit: Frau aus UA, Shutterstock

Potential Side Effects of Amoxicillin

Like any other drug, amoxicillin is not without potential side effects.

These include:
In severe cases, amoxicillin can cause the following clinical signs:
  • Rash
  • Excessive scratching
  • Breathing difficulties
  • Fever
  • Swelling of the face
  • Wobbly walking (incoordination)
  • Prolonged lack of appetite

As a general rule, if you think your cat is displaying adverse signs to a medication, consult a veterinarian promptly to assess whether adjustments or modifications in their treatment plan are necessary.

divider 1 paws

Frequently Asked Questions (FAQ)

Are There Any Risk Factors for Amoxicillin in Cats?

The biggest risk for Amoxicillin use in cats is self-prescribing it to your cat without a veterinarian’s input.

How much Amoxicillin your cat needs will be entirely up to the vet. Vets have to take caution when prescribing amoxicillin for pregnant or lactating cats and in those with liver or kidney diseases. Also, the vet would not prescribe this antibiotic if your cat is allergic to amoxicillin or other penicillins, beta-lactams, or cephalosporins.

Can I Give Human Amoxicillin to My Cat?

Even if the ingredients used are similar for humans and animals, veterinary amoxicillin prescribed by a veterinarian is the only choice for your cat. Amoxicillin for human use risks exposing your cat to toxic substances, such as certain chemical preservatives or flavors. Drugs made for human consumption should never be offered to pets; they often have completely different concentrations when compared to those made for your cat, and therefore can be extremely dangerous for your pet.

Veterinarian-holds-a-black-American-Shorthair-cat
Photo Credit: 89stocker, Shutterstock

Does Amoxicillin Have Any Drug Interactions?

If your cat is taking any other medications, vitamins, herbal medicines, or supplements, it is recommended to notify the veterinarian during your pet’s veterinary visit.

divider 2 cats

Conclusion

Amoxicillin is an antibiotic with a relatively narrow spectrum of action that is prescribed for skin, gastrointestinal, respiratory, or urinary infections of mostly gram-positive bacteria. It is often combined with other drugs for broader coverage in some cases.

Though rare, amoxicillin for cats can cause adverse reactions, in such cases, you should promptly seek veterinary care for your pet. Above all, it is important to never self-prescribe or self-medicate an antibiotic for your pet.


Featured Image Credit: Sonis Photography, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

4 Responses

  1. my cat has very bad breath. He eats well, but now his chin is swollen. I noticed he has also has been breathing with his mouth open, and he drools sometimes. I have no money for a vet right now! But I have amoxicillin for cats. Will that help his mouth infection? PLEASE HELP! Thank you!

    1. Sorry to hear about your cat‘s oral health issues, Juanita. We do not recommend that you give your cat an antibiotic medication without a doctor's examination, diagnosis, and prescription. This could make his situation worse, as what he might need is tooth extractions and a comprehensive treatment plan.

  2. I took a really sweet stray cat in from the cold four days ago. Have never seen her before. Looks to be about 10 months of age weighs maybe 7 pounds. Has had loose stools pudding like 4 or five times a day. I gave her 1 cc of stranded a couple days ago with no improvement. She won’t use the litter box even.? I am ready to throw back into the cold as I’m retired and can’t afford a vet.
    Amoxicillin for cats in the fridge. Wondering if I should try it and how much she should have? Can you advise?

    1. Hi Dolores, please do not self-medicate this cat. The loose stools are likely due to parasites, and Amoxicillin does not work for that. Also, amoxicillin is an antibiotic, and we should never use it without a veterinarian’s prescription. This is very important to prevent the development of drug-resistant bacteria. Thanks for giving the cat an opportunity hopefully, you can find a way to get her the medical care she needs.

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Why Chicken Bones Are More Dangerous for Cats Than Most Parents Realize

Chicken bones seem harmless enough, but for cats, they can cause serious damage quickly. Whether your cat swiped a piece off the counter...

Fantastic Pet Pantries and Where to Find Them

Let’s face it: times are really tough right now, and those of us in the 99% are struggling with the cost of just...

Ask Dr. Paola – Help! My Cat Refuses to Drink Water! (April 13, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

Why Healthy Cats Still Vomit Sometimes (And How to Respond)

A cat that just vomited needs a specific kind of care, and the feeding decisions you make in the next few hours actually...

More related

How Many Muscles Does a Cat Have in Each Ear? Vet-Reviewed Anatomy (With Infographic)

When it comes to dogs, we all know how good their senses are, especially for smelling and hearing. But in this regard, cats...

Fresh Step Cat Litter Review of 2026: Recalls, Pros & Cons

Review Summary As any cat owner knows, buying the right kind of litter is paramount when you have a kitty. So, if you...

Can Cats Eat Pork Rinds? Vet-Reviewed Facts & FAQ

If you frequently eat pork rinds either as a snack or as part of a meal, you’ve probably experienced your cat wanting some....

Rare Cannabinoid Company Hawaiian Choice Pet CBD Oil Review 2026: A Detailed Look

By now you’ve no doubt heard about the benefits of CBD for humans. You’ve probably also heard that this hemp product can be...

Keep reading

Can Cats Eat Shrimp? Vet-Reviewed Facts & FAQ

So, you know your cat loves fish, but she seems to be drawn to that shrimp you’re enjoying. Naturally, this will lead to your wondering if cats can eat shrimp. Is shrimp safe for your cat to eat? The short...

Can Cats Eat Shrimp

Why Does My Cat Have a Stuffy Nose? 9 Vet Reviewed Reasons

If your cat has suddenly started sneezing and has trouble breathing through their nose, you might be a bit worried. Cats end up with sniffles and stuffy noses, technically known as rhinitis, for various reasons, from allergies to colds. While...

cat nose -pixabay

How Long Can You Safely Leave Your Cat Alone? Vet Approved Tips & Alternatives

Many of us cat owners need to leave our cats alone on a regular basis. But where’s the line between an okay amount of time for your cat to be left alone and too long? The answer depends on the...

fluffy cat lying on windowsill

Can Cats Eat Apricots? Vet-Approved Nutritional Facts & Safety Tips

Apricots are a delicious fruit and an excellent source of essential vitamins and antioxidants for humans. Many people enjoy this amazing fruit and might consider sharing pieces with their feline friends, but can cats eat apricots? Is it healthy for...

Can Cats Eat Apricots

How to Tell if My Cat Has Worms? 5 Vet-Reviewed Signs

Parasitic worms are repulsive to think about, but they’re a common health problem for cats. Along with being off-putting, worms can cause severe complications for your cat if left untreated. Fortunately, worms can be treated safely and effectively in cats,...

cat owner belly rubbing her cat

Why Healthy Cats Still Vomit Sometimes (And How to Respond)

A cat that just vomited needs a specific kind of care, and the feeding decisions you make in the next few hours actually matter. Too much too soon can make things worse. Nothing at all for too long isn’t great...

sick cat lying on the sofa

Why Does My Cat Stare at Me? 7 Vet-Reviewed Reasons for This Behavior

You’re alone in your home, just going about your business, and you suddenly get the sinking feeling that you’re being stared at. You look out the window—nothing. You call out and ask if anyone’s there—no response. That’s when it hits...

Grey tabby cat with intense golden eyes

10 Best Lickable Treats for Cats in 2026 – Reviews & Top Picks

Cats can be picky eaters, leaving you frustrated about spending money on cat food that goes uneaten. If you’re looking for ways to get your cat to eat, providing lickable treats is an excellent way to entice your cat. Most...

woman feeding her cat with a treat

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.