Amoxicillin for Cats: Dosage, Safety & Side Effects

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A white kitten is being given a pill by a vet.

Amoxicillin is a common antibiotic prescribed for both cats and dogs to address a variety of bacterial infections. Amoxicillin has many brand names as well as generic forms.

Amoxicillin For Cats Overview

Medication Type:
Tablet, Liquid
Prescription Required?:
FDA Approved?:
Common Names:

In this article, you’ll learn what amoxicillin is, the types of infections it may be used for in cats, potential side effects, and some other useful info and frequently asked questions.

What Is Amoxicillin?

Amoxicillin is an antibiotic called an aminopenicillin. As a bactericidal antibiotic, it has the ability to kill certain strains of bacteria causing infections.

Amoxicillin may be used for infections of the respiratory tract, urinary tract and bladder, some gastrointestinal infections, and infections of the skin and soft tissues. Because there are many antibiotics out there, a veterinarian should always be responsible for deciding which one is best to use for a particular patient.

Because amoxicillin-clavulanate, commonly known as the brand Clavamox, has a broader spectrum of action against some bacteria, it is more commonly used than regular amoxicillin, especially for cats.

What Does Amoxicillin Do for Cats?

As a bactericidal antibiotic, amoxicillin has the ability to kill certain kinds of bacteria causing infections.

In kitties, it may be used most often for upper respiratory infections, urinary tract infections, skin infections, or infections resulting from a bite wound or injury.

Amoxicillin works by binding directly to certain parts of the cell membrane of susceptible bacteria, inhibiting development of the cell wall and making the bacteria unstable, thus killing them.

It’s very important to note that amoxicillin is not effective against viral infections, a common cause of upper respiratory conditions in cats. Therefore, it’s always important for a vet to decide if use of an antibiotic is warranted.

Side Effects of Amoxicillin for Cats

A gray cat is laying down next to some food.

The side effects of amoxicillin are usually mild and infrequent, involving gastrointestinal upset like vomiting and diarrhea.

Side effects of amoxicillin in cats are typically mild and infrequent but when they do occur, most often include digestive upset, like vomiting, diarrhea, and a decrease in appetite.

Oral amoxicillin, like many broad-spectrum antibiotics, can alter the normal, beneficial bacteria in the digestive tract, which is often a cause of digestive upset if it occurs.

Giving amoxicillin to your kitty around the time of a meal can help to offset these possible effects. If side effects like these continue, it’s important to ask your vet for further advice.

While discontinuing an antibiotic may relieve the side effects, this will also leave the original bacterial infection untreated. If your kitty is dealing with a very concerning infection, your vet may, for example, recommend starting a probiotic as opposed to discontinuing an antibiotic.

Severe allergic reactions to amoxicillin are extremely rare but can include rashes, hives, fever, and changes to red and white blood cell counts. To the rare kitty this might happen with, these effects would occur with even a very small dose. In other words, if your kitty is doing well at a prescribed dose, an accidental extra dose or overdose would not cause these effects.

Also Read: 10 Best Probiotics For Cats

Amoxicillin for Cats Dosage

A cat with a cone on its head.

Follow the dosing instructions provided by your veterinarian. Most vets call for a dose every 8-12 hours.

The FDA-approved, labeled dosage for amoxicillin for cats is 50 milligrams per cat or 11-22 milligrams per kilogram (about 5-10 milligrams per pound). This labeled dose is for specific bacterial strains contributing to upper respiratory tract infections, genitourinary tract infections, GI tract infections, and skin and soft tissue infections.

Interestingly, the labeled dosage for cats for amoxicillin calls for giving it just once a day. However, this dosage is generally no longer considered in veterinary medicine to be effective for most infections.

Most vets are using it off-label at every 8-12 hours, similar to the labeled dosage for dogs. If your vet decides to use amoxicillin for your cat, they will decide on a recommended dosage amount and schedule that is most appropriate depending on the type of infection being addressed.

It is very important to remember that dosage amounts and how long a cat is treated for will vary depending on the size of the cat and the type of infection that is present. These decisions should be left to an attending veterinarian.

It is also very important to follow a veterinarian’s instructions carefully when using any antibiotic. Using an antibiotic when one is not appropriate (i.e. for a viral infection or behavorial/stress-related causes of inappropriate urination) or stopping an antibiotic sooner than the prescription calls for can contribute to bacteria becoming resistant to an antibiotic.

If your cat’s signs of illness have not improved within 5 days, it’s important to touch base with your vet to determine best next steps. If your cat does show signs of improvement or even if signs of illness appear to resolve, always make sure to finish out the fully prescribed course of antibiotics.

Amoxicillin typically comes in both a liquid form as an oral suspension as well as tablet form. Your veterinarian may have a preference of which form to use, or may leave the dosage form up to you depending on which will be easier to administer.

If your kitty will take a pill mixed with or hidden in food or a treat, this is often easiest and involves the least amount of struggle. However, if your furry friend is the type that will eat everything in the bowl but the tablet and leave it at the bottom, you may need to consider liquid if you are not adept at administering a pill directly into your cat’s mouth for her to swallow it.

The liquid form typically needs to be refrigerated. It is often reconstituted with water at your vet’s practice when you receive it. If your vet prescribes two bottles, they should provide you with instructions on how to mix up the second bottle. Because liquid amoxicillin should be discarded after 14 days, it is important not to mix up a new bottle until you are ready to use it.


Amoxicillin is one of the oldest, tried and true antibiotics we have and although newer antibiotic classes have been developed, amoxicillin still has valuable clinical uses.

However, it’s really important to make sure it is only used when dispensed or prescribed by a veterinarian, and that all prescribing instructions are followed. Indiscriminate use of any antibiotic can lead to resistant bacterial populations, which make treating infections more difficult.

Always make sure to give an antibiotic prescribed by your vet for the full number of days indicated, even if your kitty looks like he’s feeling better.

Drug Dosing Disclaimer: We are only able to provide doses for medications that are FDA approved for use in cats and only as the label guidelines dictate. For medications that are used off-label we can only provide guidelines and safety information for use. Safe and appropriate dosing for off-label medications can only be determined by a primary care veterinarian.

We encourage you to work with your veterinarian to determine if a particular medication is appropriate for your cat. Changing or adjusting a dose for your cat on your own without consulting with a veterinarian can carry risk. We do not encourage use of medications prescribed for human use in pets without first consulting with a primary care veterinarian.

Frequently Asked Questions

Is Cat Amoxicillin the Same as Human Amoxicillin?

Amoxicillin comes in a liquid suspension, tablet, and capsule forms. The most common form given to cats is the liquid suspension or the tablets, both in specific veterinary preparations.

While human amoxicillin is actually the same medication, the dosage forms available for people may be problematic for use with cats. The lowest tablet dosage for people of 125mg will be much too high for most cats. 

The generic human liquid suspension could be used, however the volume of medication in some available preparations may be far more than what is needed for a cat’s typical dosage period, making them less practical.

How Long Does Amoxicillin Take to Work in Cats?

For susceptible bacterial infections, you will typically see noticeable improvement within 2-3 days of use. Full resolution for an infection depends a lot on the location and severity. This is why it’s always important to follow the prescribed directions and to finish out all of an antibiotic even if your kitty is looking much better.

Is Amoxicillin Poisonous to Cats?

Amoxicillin is not poisonous to cats, is very safe at prescribed doses, and side effects are uncommon.

However, if a cat were to get into and consume an amount of amoxicillin much higher than a typically prescribed dosage, like say, a 500mg human tablet, severe digestive upset may occur. Neurologic changes, like an inability to walk normally (termed ataxia) have been reported in dogs, as well as elevated heart rate and breathing changes.

Many medications can cause significant negative health effects if very high doses inappropriate for the patient are ingested. So while amoxicillin is not in itself a toxin, if you suspect your kitty has ingested an overdose of her own amoxicillin or possibly any prescribed for you or a family member at home, always notify your veterinarian and/or get in touch with Animal Poison Control to determine what steps may need to be taken.

How Much Amoxicillin Do You Give a Cat?

In short, what your veterinarian prescribes! Amoxicillin has a wide dosage range. The dosage and frequency can vary depending on the type of infectious condition being treated, so it’s always best for your kitty’s vet to determine what is most appropriate. 

And always remember that even if your kitty appears to be feeling better, to always finish out a prescribed course of antibiotics, as this helps to reduce the risk for development of bacterial resistance to antibiotics.

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About Dr. Chris Vanderhoof, DVM, MPH

Dr. Chris Vanderhoof is a 2013 graduate of the Virginia-Maryland College of Veterinary Medicine (VMCVM) at Virginia Tech, where he also earned a Masters in Public Health. He completed a rotating internship with Red Bank Veterinary Hospital in New Jersey and now works as a general practitioner in the Washington D.C. area. Dr. Vanderhoof is also a copywriter specializing in the animal health field and founder of Paramount Animal Health Writing Solutions, which can be found at Dr. Vanderhoof lives in the Northern Virginia area with his family, including 3 cats.

41 thoughts on “Amoxicillin for Cats: Dosage, Safety & Side Effects”

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  1. Janay Bonforti

    I feed ten feral cats friskies canned cat food. Once a month I open two fish amoxcillin capsules and blend it in with their food. Should I be doing this because it takes care of their worms.

    1. Rusty Simpson

      Then why do you mislead people to your site by stating dosage? It cost 75$ at least for the appointment alone before they even look at your cat & they charge more for pulling cat teeth than human! & where I live you’re lucky to find a vet that’s not booked for months! Be real! I have to wait in the car while a vet tells me ridiculous prices! Your misleading people by telling them dosage & almost scold them for asking! “ Oh you have to take them to the vet”-then don’t use it to direct people to your site for advertising money!

    2. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Rusty,

      It sounds like you’re understandably very frustrated and what you’re going through with cost and availability issues is not uncommon. Unfortunately, our profession is seeing a significant shortage across the country that we’re struggling but trying hard to meet. Price increases have also been significant over this past year with inflation. Most veterinary personnel, including doctors have limited or no control over either challenge which has also been frustrating. Higher prices set by upper level management and less availability makes it harder for us to provide good care.

      We don’t intend to be misleading with our article content and I’m sorry you were not able to find exactly what you were looking for. Our goal is to provide as much comprehensive information as possible while understanding that we are limited in what we can provide outside of a direct doctor-patient-client relationship.

      Next to pain medications, antibiotics are the most widely misused medication type. This is an increasing problem in human medicine too, and human healthcare is cracking down on us as well, removing some higher end antibiotics from availability for pets. This makes our common antibiotics all the more important to conserve for when they’re deemed medically necessary by a veterinary professional.

    3. Vera Georgieff

      Only $75.00 for an appointment? Where are you? In another planate? Please, let this doctor explain to us everything about those medications because those vets (especially in CA) don’t want to waist there time asking us questions about our pets allergies to everything, medication already taken, etc. I want to know everything truly and then, decide what, where, how, and how much to give to my pet.

    4. Crystal King

      I use diatomaceous earth (mixed in with dry food) the grease from the food will usually absorb it. It also can help with fleas and bugs when applied on the fur. I use Harris Brand, it’s very inexpensive and is wonderful. Please do make sure to get only FOOD GRADE diatomaceous earth. It’s used as an anti-caking agent in equine food etc.good luck!

    5. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      For any readers who would like more info on diatomaceous earth, have a look at our article Diatomaceous Earth for Cats for some applications and uses, included suggested doses for deworming. While there is little scientific studies or literature to support its use for deworming, many swear by it. I would at least find it preferable to use of fish amoxicillin for sure.

  2. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

    Hi Janay,

    Firstly, thanks so much for being a caretaker for a feral cat population. Those outdoor kitties need our help too.

    But unfortunately, I would feel that the addition of the fish amoxicillin capsules is misguided for two reasons. One, you mentioned that amoxicillin will address “worms”. By that, I assume you’re referring to intestinal worms like roundworms, hookworms, or tapeworms, which these kitties could certainly have. Amoxicillin has no effect against worms in any way, only against bacteria, as I mentioned in the article, so the amoxicillin you’re adding would not be helping with the problem you’re trying to address.

    Two, fish amoxicillin is designed to be added to the water of a fish tank and absorbed by fish. Fish amoxicillin is not intended to be used for other species of animals and it is in fact, not the same strength or formulation as what we use for pets or even people. Additionally, and perhaps surprisingly, the reason you can purchase fish amoxicillin over the counter is that it is not regulated by the FDA at all. This means there could be a lot of variability in the quality and manufacture.

    Adding the fish amoxicillin capsules to the feral colony’s canned food is unlikely to be providing any significant benefit, and is more likely to be contributing to amoxicillin-resistant bacteria. This could mean that if one of the kitties truly became ill, a medication like Amoxi-Drops or Clavamox may not be as effective as it would otherwise be.

    I do not work with any feral populations myself, but it has been my understanding that there are often local vets that are willing to help keep these outdoor kitties as healthy as possible. Hopefully, there may be a vet in your area that could help provide some more specific guidance.

  3. Chris

    We just got our cat,Willy, back from the vet for a dental cleaning. We brought him the blood work-up results for a dental cleaning last year from another vet. The blood work-up was normal. (However, the cholesterol was 427, but that vet didn’t have us 12 hour fast Willy. But this isn’t the main point of my question).

    Based on Willy’s last year’s blood work-up he didn’t do a blood work up and administered the anesthesia and successfully cleaned his teeth.

    Question 1: Is this really recommended? No blood work-up, and going on a previous year’s blood work-up from the other vet and administering the anesthesia for the dental cleaning?

    Question 2: We we’re given liquid antibiotics to administer twice a day orally and three pain medication pills to administer once a day for three days. According to them, the anibiotics was for possible infection due to the cleaning and the pain medication was for pain from the cleaning. In your experience, does this seem unnecessary and far afield?

    The antibiotics is Amoxicillin/Clavulanate.
    The pain medication is Onsior.

    The vet last year didn’t give us the antibiotics and pain medications.

    Also, like I said, last year’s vet didn’t have us do a 12 hr fast for Willy’s dental cleaning.

    This vet did advise us to do Willy’s 12 hour fast.

    As it turns out, I did some research on this a few days before Willy’s recent cleaning to learn this is highly recommended because under anesthesia Cats (and dogs too, probably) can’t vomit up a recent meal choking on it and sending it down into the lungs to cause potentially severe complications.

    Question 3: Did last year’s vet proceed dangerously not recommending a 12 hour fast, or is there a technology they utilized to prevent potential choking from vomiting of Willy?

    Please help me. I’m confused and worried…



    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Chris. I’ll do my best to clarify some of your questions. I’ll try to be objective and impartial with my answers, since it’s always important to realize that any medical situation can vary quite a lot from patient to patient. Speaking with your own vet is usually best to best understand the rationale for certain decisions.

      First, fasting prior to bloodwork in veterinary medicine is uncommon, except for certain types of testing. Cholesterol, while sometimes relevant for our patients, is far less relevant compared to people, as pets do not develop the same type of diseases from high cholesterol, like atherosclerosis and risk for heart attacks.

      Many veterinarians consider having updated lab work within 30 days of an anesthetic event to be a standard of care. However, some vets may adjust this based on their own discretion, which may depend on a patient’s age and any prior health history. Some veterinarians may make this a longer interval, and others may even make lab work optional. Any potential risks of those decisions should always typically be discussed.

      Use of antibiotics and antiinflammatories for dental procedures may vary based on an individual veterinarian’s judgment in a particular case. Antibiotic use during and after dentals is hotly debated in our field. One argument is that during the process of cleaning, bacteria in the mouth may enter the bloodstream which leads to risk of endocardiosis on heart valves, and showering the kidneys and other vital organs with bacteria, so antibiotics should always be used regardless of dental disease severity.

      The other argument is that unless extractions are being performed which requires tissue healing, or unless a pet has heavy dental disease with concern for pre-existing infection, that antibiotic use during or following a dental cleaning is not needed and would only contribute to antibiotic resistance.

      Your veterinarian may fall in the first camp or otherwise may have felt that the amount of tartar present warranted sending antibiotics home.

      As far as the anti-inflammatories for 3 days goes, there may be no right or wrong answer there. Veterinarians try their best to ensure their patients are not in any pain. How much discomfort occurs during a regular dental cleaning when no tooth extraction has occurred is also debated.

      If there was extra gingivitis present that led to more bleeding during cleaning or if a lot of extra scaling under the gums was needed, your vet may have felt that an anti-inflammatory was warranted to ensure your kitty was more comfortable after going home.

      As far as fasting goes, many vets would agree it’s a standard of care to have patients fasted for 12 hours prior to any anesthetic procedure. As you alluded to, this is primarily to reduce the risk of regurgitation or aspiration during a procedure, since the pet cannot swallow on their own. Other precautions to guard against this are taken as well, including the placement of the endotracheal tube that seals off the airway and is only removed once the pet can start swallowing again.

      I hope that information helps. I always encourage folks to reach out to their own veterinarian if there are specific questions about the rationale for certain testing, treatments, or care. In an effort to simplify things for folks, a veterinarian may not communicate his or her full thought process, which can sometimes lead to misunderstandings.

  4. Loreen

    Hey doctor, I hope you are having a great day,
    So I take care of an outdoor cat, I always feed him form my food not wet or canned, he is 10 months old,
    I’ve noticed for the past few weeks that he has right in the corner of his lip an Infection with pus (only in on side), some days it gets better and not even noticeable and the other days it get worse, It appeared out of no where I don’t know from where did he get it (maybe he got into a fight) since he is an outdoor cat and plays alot with other cats in the neighborhood, the problem is When I saw it today it looked bad and very concerning because the infection is getting bigger and the side of the lip and the skin around it looks like its getting eaten up or (erosion) and there is pus + now when he closes his mouth normally you can see part of his tooth (because some of the skin is gone from the infection as I mentioned before) I wish I could show you a picture to make what I’ve said clear. Thank god his appetite is very good and he eats everything so the infection is not affecting his eating. Also he is playful and hyper as he always has been so he doesn’t seem in pain. (hopefully). So I’ve guessed since there is pus I should give him antibiotic? (amoxicillin?) Please correct me if I am wrong. Thank you so much doctor for your time and reading my problem please help me and tell me what to do and what dose and how many times a day ( Since I can’t go to a vet because there is no one near me unless If I drove for 3 hours and I can’t) + please excuse my bad English (I’m not a native speaker) thank you so so much again.

    1. small mallory photoMallory Crusta

      Hello Loreen, thank you for commenting! Not the original writer, but While amoxicillin would likely be prescribed to a cat in this condition, you will have to get a vet’s approval to use the antibiotic. I would recommend finding a veterinarian who practices telehealth and getting the prescription from them so that you can purchase it. Wishing your cat all the best!

    2. Sonia

      Yo alimento a 7 gatos de calle pero una tuvo gatos y se los robaron y ahora tiene leche que no salió y no se que hacer pues no tengo ni l dinero para pagar un veterinario y compre amoxilina de 500mg le he estado dando de a poco en la comida húmeda la verdad es muy triste verlos en la calle y más no poder hacer mucho por ellos

    3. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Question Translated to English per Google Translate: I feed 7 street cats but one had cats and they were stolen and
      Now she has milk that didn’t come out and I don’t know what to do because I don’t even have it.
      money to pay a vet and buy amoxilin 500mg I have
      been giving little by little in wet food the truth is very sad
      seeing them on the street and not being able to do much for them.

      English Response: Hi Sonia, thank you for doing your best to take care of these street cats. If the mother cat just had the kittens removed, and you are just concerned that she has no kittens to nurse and her mammary glands are still full, her mammary glands will eventually stop producing milk and there is no reason she would need an antibiotic.

      However, if you are worried the mother cat has a true mammary gland infection, I hope the amoxicillin will help. I can’t get exact, but cutting the 500mg tablet in about 6 pieces and using 1 piece every 12 hours would be approximate for about a 10lb adult cat. I don’t know if the mother cat will let you touch or handle her, but warm compresses (like a warm washcloth) over the mammary glands can also help with a mammary infection.

      Reponse translated by Google Translate into Spanish: Hola Sonia, gracias por hacer todo lo posible para cuidar de estos gatos callejeros. Si a la madre gata le acaban de quitar los gatitos y a usted solo le preocupa que no tenga gatitos que amamantar y que sus glándulas mamarias todavía estén llenas, sus glándulas mamarias eventualmente dejarán de producir leche y no hay razón para que necesite un antibiótico.

      Sin embargo, si le preocupa que la madre gata tenga una verdadera infección de la glándula mamaria, espero que la amoxicilina le ayude. No puedo ser exacto, pero cortar la tableta de 500 mg en aproximadamente 6 piezas y usar 1 pieza cada 12 horas sería aproximado para un gato adulto de aproximadamente 10 libras. No sé si la madre gata te dejará tocarla o manipularla, pero las compresas tibias (como una toallita tibia) sobre las glándulas mamarias también pueden ayudar con una infección mamaria.

  5. Cindy Cay meeker


    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Diane,

      Thanks for your comment, but this is not considered a very safe or responsible practice for two main reasons.

      The first is that fish amoxicillin is not regulated by the FDA, so its manufacture is not checked for any standard things like purity, quality of ingredients, contaminants, etc. It is not made or intended for oral use by people or pets. It is only made to be added to a water tank.

      The second is that one of the main reasons to take your cat to the vet is to get a better idea of what’s going on and if an antibiotic is indicated. There are lots of conditions that can mimic bacterial infections, like sneezing from herpesvirus or straining to urinate from stress, which don’t warrant antibiotics. Indiscriminate antibiotic use will eventually lead to resistance to all antibiotics within that drug class.

      Additionally, the 500mg size of capsules that fish amoxicillin comes in is way too high for most cats. If the capsules are then being split or divvied up at home, the question has to be raised of what dosage is really being given at all.

      Prescription amoxicillin really isn’t that expensive and while it can be understandable to try to avoid the cost of a vet exam, it’s very easy to get into a hard place when a mistake is made trying to diagnose and treat your pet’s condition on your own. It can end up being more costly.

    2. sherry

      I hear what your saying Doc but the reality is there are a lot of us, animals and humans that are using fish antibiotics because we have no other means. Sometimes it is money, sometimes it is a lack of local care. I am sure there is misuse but I personally am very capable of adjusting dosage for myself and animals. I wish we were allowed access to antibiotics via a OTC method that would give us quality products but we are not. In so many counties (Mexico) the average citizen can purchase OTC. It something that needs to change but appears to be going the opposite way. Ranchers can no longer get meds for their animals in my state . How long before diseased cattle become commonplace. Thanks for the mention of telehealth for a vet. I had no idea that existed.

    3. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Unfortunately Sherry, we only have a limited number of antibiotics available to use and antibiotic resistance is a huge concern. Having OTC antibiotics would lead to flagrant misuse and select strongly for more and more highly antibiotic resistant strains of bacteria. At least once every couple of months now I’m seeing a patient with an infection involving a bacterial strain so drug resistant that there are literally no oral antibiotic choices left to use. Even among the highly reserved antibiotics. This type of frequency was not seen, at least by myself and close colleagues of mine, 5-10 years ago. And there’s really just no good treatment alternatives in many cases. I know a lot of these same concerns have raised similar concerns on the human medicine side, which is now having unfortunate repercussions for food animals that we could not have predicted even 10-20 years ago.

  6. Nelly

    Hi, I don’t know where you’re located, but maybe a rescue or a city shelter can help. There a lot of cat rescues. Google Neighborhood Cats and email or call them, tells them what’s going on and they probably can direct you to resources that can help. Good luck!

  7. Jenifer

    I have a 6 mo old kitten who weighs under 2 lbs. I have treated her for worms. All she does is sleep. Not active at all. What can I do to help her to gain weight an be a kitten?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Jennifer, thanks for your question. Having a 6 month old kitten that is less than 2 pounds is certainly something to be concerned about but unfortunately there really could be a number of things contributing to your little kitten’s condition. The best thing is to have your kitty checked by a veterinarian as soon as possible. Providing some good history and having an exam performed are important starting points. Although you have treated for some worms, there is no catch-all dewormer. Your vet can run a stool sample to help make sure none have been missed. Kittens can also have certain viral infections that are routinely tested for that can contribute to poor growth and health problems. It can also be helpful to discuss diet and nutrition as well.

  8. Dominique

    Hi Dr. Chris,
    I think my cat might have a UTI because she’s having trouble releasing a full bladder and/or having the urge to go when she doesn’t really need to. I also noticed a jelly like bloody discharge in her urine (a little amount but it’s definitely there). She’s about 10lbs and I found a single capsule amoxicillin dosage of 500mg, is that safe to give her and will it be enough if I only giver her one?
    Thank you

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Dominique, thanks for your question. In any pet showing such signs, but especially in cats, it is important to get an actual diagnosis if possible before considering antibiotics. While a UTI may be more likely in a female cat, we can also see conditions like bladder stones, and stress-related urinary conditions like idiopathic cystitis, which aren’t treated with antibiotics.

      Even if your kitty did have a UTI, the amoxicillin you have would not be appropriate to give. It would be much too high a dose and because of how it kills bacteria and works in the body, must be given at least twice a day for several days at least. Giving this single dose would be more likely to cause GI upset, have minimal effect on a UTI, and promote bacterial resistance to amoxicillin.

      Scheduling an appointment with your vet would be the best thing to do here.

  9. Michael

    I clipped my cats claw to deep now it seems infected and is swollen I have been cleaning and wrapping it some times it looks to be getting better then it doesn’t A Vet is out of the question as they charge to much up front and won’t do payment plans Can I give him a small dose of amoxicillin? Is there anything over the counter I can use too

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Michael,

      The best I could suggest generally for something like that is to use very dilute chlorhexidine as a soak for 5-10 minutes at least twice a day. Not the easiest thing to do depending on the cat, but it can work well as an antiseptic for broken/torn/quicked nails.

      Keep in mind that nail injuries can take a few weeks to fully heal as the newer nail grows out.

      Human amoxicillin dosages are typically inappropriate to use in cats as they are much too high and more likely to lead to unwanted side effects. If you don’t have the right dosage of an antibiotic for the right length of time, it may not fully help and only lead to bacterial resistance.

      I can’t comment more as it’s impossible for me to know if this is a typical delay in healing that can be seen with nail trauma even without infection present, or something more concerning. Uncommonly, nail trauma can lead to infection of the tissues of the toe. If there is any swelling, pain or discharge at that digit, veterinary care would be needed for sure.

      Any kind of out of pocket medical care is going to be expensive and helps to have some funds set aside for emergencies. There may be a telemedicine service you could look into that might be less expensive and less stressful for your kitty for a situation like this if healing delays continue.

  10. Baz

    Pretty sure my cat has a UTI
    -Indoor Cat – lives with 2 other cats
    -Licks his “private” area a lot
    -Hugs water with his giant arms and drinks a lot
    -Has large urinary output + sometimes has a hard time holding it in (had a few accidents)
    -Urine does not have the strong urea smell or discoloration
    -My mom said, she spotted him possibly dripping
    -Other cats don’t have the same symptoms
    -Now crying in pain as he licks his privates

    My vet can’t physically see him 2 weeks because of the holidays. I don’t want my cat to develop urosepsis. Anyhow, online says Cats: The recommended dosage is 50 mg (5–10 mg/lb) once a day. However, my cat is 17.2 pounds – is 50 mg the max daily dosing? Or can I do 85 mg – 170 mg x probably 7 days (since he is a male)?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Baz,

      Unfortunately it’s not clear that your cat truly has a UTI with what you’ve described, or that a UTI if present, is the only issue your cat has. The large volume of urine output and the increased need to drink are not uniquely associated with a UTI but we can see these changes with other metabolic or endocrine diseases, like kidney disease, diabetes, etc. Male cats also are more susceptible to sterile urinary bladder and tract inflammation, and urinary blockages which can appear very much like a UTI but aren’t responsive to antibiotics. The licking of private areas and urinary pain could be concerning for this.

      I would say for a cat for amoxicillin dosing and especially for bigger cats, we likely need to be more accurate in dosing compared to your “average” 10lb cat where we should be dosing based on their weight. But beyond that, I cannot assist with specific dosing for your cat beyond what is generally found in the article.

      But I’m also concerned that treating with an antibiotic alone could be missing something more important that’s going on here. I would suggest seeing if your vet could at least consult with you by phone to discuss these signs and concerns more and they may be able to provide you with accurate dosing if appropriate.

      If your vet is truly not accessible for two weeks, and especially if signs of urinary irritation or pain are present, I would highly suggest looking into other nearby practices that have openings in the meantime as soon as possible or any urgent care/ER locations that could see you and your cat sooner.

  11. Kacy

    The vet prescribed amoxicillin for an abscess on my cat’s face. Why on earth is it strawberry flavored?? Ridiculous! It’s obvious that this product was not meant for animals. My cat of course wants nothing to do with it. Is it possible to find it unflavored? What can I do to help the infection if my cat won’t take the antibiotic?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Kacy, yes it’s not surprising that the strawberry flavored amoxicillin is not very appealing to your cat. However, it would be appealing to a person, especially a child, and that’s what that preparation is likely intended for. If you picked it up at a human pharmacy, you might be able to ask the pharmacy staff if they carry an unflavored form, explaining your situation. Amoxicillin has lots of generic preparations available, including some specifically for dogs and cats. One example is AmoxiDrops. You can order it online, but it does require that your vet approve the prescription. The dosage volume may end up being different from what you currently have. Some cats may be opposed to any kind of liquid medication, flavored or not. Sometimes, working with a compounding pharmacy to get flavored chewables or even a liquid in a flavor more palatable for a cat, like chicken or fish, can work too.

  12. Gary Steinmann

    Hi Doctor. Thanks for a very informative article. I too take care of a colony of abandoned and feral cats. A 3 year old male became incontinent of urine yesterday, and when he let go on the sidewalk there were many small clumps of some discharge that was thick and similar in texture to fine mud in the urine. The urine was bright yellow and the sludge was yellowish-green. He is active, appears to be eating and consuming water normally. I know you can’t diagnose under these circumstances but the cats are in a small town and the nearest vet is two hours away. I don’t want to traumatize him needlessly if this is something minor. Do you have any general thoughts on what kinds of problems can contribute to an effect like this? I’ve never seen anything like it.

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Gary, what you’ve described does sound odd. I suppose what you’re seeing could be purulent or pus type material coming out with the urine when this cat urinates. Cats can also have mineral grit and mucus that may come out in urine as well. And while I don’t mean to insult your senses in anyway, but because I’ve encountered it before, is there a possibility that this is not urine you’re seeing but diarrhea? I have seen some folks mistake diarrhea for urine and vice versa.

  13. Gary Steinmann

    That’s an interesting possibility, one I would never have thought of on my own. Having not seen any recurring evidence of an ongoing incontinence issue, I suppose it’s worth considering. I collected a sample from the sidewalk at the time and sealed it in the refrigerator. If I take it to the vet soon, could a microscopic observation reveal anything definitive one way or the other?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Gary, I think it’s a possibility worth considering. You can have diarrhea that’s very watery and yellow, which could resemble urine, but might make more sense as stool material given the other stuff you’re seeing in it. Depending on how well the sample is preserved, it may definitely be possible to determine whether it’s stool or urine. Microscopically, you would expect to see some different characteristics too.

  14. Green

    My cat was lethargic and sneezing. Vet visit showed high wbc & cat was diagnosed with respiratory infection. Covenia injection & Depo Medrol injection was administered. Cat improved then 4 weeks later had yearly check and vaccines updated. All seemed well….. until one week after vaccines cat became lethargic but with no other outward symptoms. Vet did blood work again which turned out normal and did FIV & leukemia test which turned out negative. Fever of 104.9 was found & diagnosis of possible relapse was made. Another Covenia injection was given but with Dexamethasone this time. One week has passed and cat still extremely lethargic but is eating and drinking some. I believe fever may still be present. — What can I ask vet to test for this time & if fever is still present on visit, how can it be brought down. Also is it normal for a cat to continue to have fever and lethargy 6 days after being given the above meds…if diagnosis is relapse. If it turns out not bacterial and is viral… again is fever and lethargy for this long normal for that?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Green,

      I can’t say if these events are connected or if they are separate, given the month of time in between. A high fever in a cat can unfortunately be caused by a number of categories of things. What you have with a fever that high is what we call a fever of unknown origin. If your cat is on the younger side (maybe <6-7yrs) it may be more likely an infectious cause, such as a recurring virus. If there are upper respiratory signs still present, there are PCR panels that can be run to check for a host of respiratory pathogens. Convenia is a very common choice for cats, but there are some organisms, like Mycoplasma for example, for which it is not effective.

      If your cat goes outdoors (or is in a multicat household), considering a cat bite wound that hasn’t presented itself yet is one thought. A high fever can occur and then the bite wound abscess shows up a few days later. It can also be helpful to run a panel for bloodborne parasitic agents, like tick borne diseases given the higher likelihood of exposure. Usually they cause abnormalities in the CBC which sounds like you’re not seeing the second time around, but not always.

      In an older cat, a high fever being caused by underlying cancer or immune-mediated disease has to be a consideration. We’ll more often advise x-rays and/or ultrasound to screen for potential causes.

      I have also sometimes treated cats empirically with doxycycline and prednisolone. In cats that improve, it’s not fully clear what the cause was, but this is usually much younger cats, so probably some kind of infection or inflammatory cause.

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Marie,
      Unfortunately, the frequency can vary a lot depending on the indication, anywhere from once a day up to 3 times a day. Beyond that I can’t provide you with more specific advice. You’d need to get in touch with the veterinarian that prescribed it for the most appropriate frequency based on your kitty’s situation.

  15. Shirley

    My male cat is taking Amoxicillin and Clavulanate Potassium, he’s not eating but drinking lots of water and throwing it up. Is this normal?

    1. Avatar photoDr. Chris Vanderhoof, DVM, MPH Post author

      Hi Shirley, I would not say that what you’re seeing is normal, but it’s hard to say if the Clavamox is responsible. If your cat had a normal appetite and was not drinking excessively prior to starting clavamox, and then you were seeing the appetite decline, drinking, and vomiting of water, I would say it’s possible the antibiotic could be related. We can see appetite changes with an antibiotic and sometimes I will appreciate patients drinking more on antibiotics as well. If this is the case, you should get in touch with your vet, because if we’re trying to treat an infection and your kitty is not tolerating the antibiotic well, your vet will need to develop an alternative plan.

      However, I don’t know what the Clavamox was prescribed for. If your cat was already not eating or having any of these symptoms already and the clavamox was added as part of the treatment plan, while it may not be responsible for what you’re seeing, I would be concerned if such symptoms are continuing. Depending on what timeframe we’re talking about, a recheck visit may be a good idea.