(I run a small cat sanctuary and am currently between vets. I'm trying to learn to do some basic treating on my own. I know when a cat is sick enough to call a vet so please don't just tell me to go to a vet. That doesn't answer my question.)

I've been doing urinalyses on my herd and am finding urinary issues from not drinking enough and probably from an all dry diet. Some cystitis and some infection. I've found a good natural compound that treats the cystitis really well, but not the infection. So I've started them on amoxicillin for UTI, I'm just not sure the correct dosage and length of treatment for each cat. When I've looked elsewhere online, I've seen 5-10mg per pound and 10-25mg per pound. Also, nothing really says for how long to give it.

Can someone offer me some better specifics on this? I've been treating conservatively so far (10mg per pound) and only for about a week but I'm still getting leukocytes showing up when I test them. I know people usually have to take a 2 week course to treat everything, but I wasn't sure about animals. Honestly, it's been so long since I've used anything but the Convenia shot, I can't remember. I'm trying to treat the infection without overwhelming their system as I just had two cats die after having the Convenia shot.

Looking for some better guidelines here. If you think it might require further testing, I'm completely open to that. Thanks.

  • 3
    I run a small cat sanctuary and am currently between vets. I'm trying to learn to do some basic treating on my own. I know when a cat is sick enough to call a vet so please don't just tell me to go to a vet. That doesn't answer my question. This comment does not make this question on topic for the site, nor does it remove your responsibility to provide Vet assistance when administering prescription medication for your pets. At least a consultation with a vet would clear this up for you and give you the answer and whether the treatment is warranted.
    – user6796
    Commented Apr 22, 2017 at 14:33
  • meta question pets.meta.stackexchange.com/questions/2160/…
    – user6796
    Commented Apr 22, 2017 at 14:35
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    Thank you all for your replies. Since I posted this, I have found a great new vet that works with me and helps me learn. To check urine I do the stick, check urine gravity with a refractometer, and am learning to use the microscope to find white blood cells. The urine gravity has been the best indicator of an issue so far. The cats do better in the winter, so I've been able to take a break for a few months, but summer is coming soon. I'm finding ways to get more water into their diet and I've gotten down the dosing on the antibiotics (which I'm trying to use less of because they disrupt their
    – Elorah
    Commented Apr 22, 2017 at 20:05
  • I just wanted to add that the way I keep my kitties drinking lots of water is by providing them with fountains of various types and sizes. I take care of a lot of kiddos and have for quite a long time. I realized at one point that for the number of cats in my care, I have very low incidents of UTI or even kidney problems, and the only thing I can really attribute this to is the fountains, which provide a continuous source of running fresh water. I would love to have your email address or be able to give you mine as I have so many things I would love to ask you about! Is that allowed on here? Commented Nov 19, 2021 at 6:43

3 Answers 3


A urinalysis can be suggestive of a urinary tract infection, but not necessarily diagnostic. In a free catch urine sample – which I am assuming is what you are collecting – there is a good chance you get bacteria or cells in the urine sample from the vagina or prepuce. In which case you may be treating a nonexistent UTI. To diagnose UTIs, vets usually obtain either a cystocentesis (needle in bladder) or urinary catheter sample.

Urine culture and susceptibility is needed to diagnose a urinary tract infection, determine what antibiotic to treat with, and determine when to stop treating. If the bacteria happens to be resistant to Clavamox, then you are breeding resistant bacteria. Inappropriately treated lower urinary tract infection could ascend to the kidneys and cause potentially life-threatening pyelonephritis.

The labelled dosage of Clavamox for UTI in cats is 62.5 mg per cat twice daily for 10-14 days. Often extra-label higher doses are used by vets. Obviously for very small or very large cats this dose needs to be adjusted at a veterinarian's recommendation.


The strips can be VERY misleading, you may not even have a UTI if you're only looking at the strips and not under the microscope. I find the white blood cell mark is always inaccurate in cats.

A complete urinalysis should be done to detect a UTI, this involves the strip (ketones, bilirubin, blood, ph, glucose are most reliable), specific gravity (checking concentration of urine for kidney function) and microscopic exam. The microscopic exam is VERY important, you can visually check for bacteria, crystals, blood cells, epithelial cells (from bladder or kidneys), casts, yeast etc.

A lot of our kitties are given antibiotics when there is no need as most of the time it is cystitis and not a UTI, which then you would only give an anti-inflammatory such as Metacam or Onsior (onsior is safest for cats).

If infections keep on returning you would need to do a culture and sensitivity (in a perfect world this should be done before first round of antibiotics) to find out what antibiotic is effective for the type of bacteria that's causing the issue.

If cystitis keeps returning it's probably stress related and you will need to help minimize their stress. Hills C/D stress diet is what we recommend for those cats as well as Feliway.

If there are signs of crystals a diet change needs to happen, Royal Canin urinary S/O or Hill's C/D is what we recommend. Wet food is very important for cats, we like to see a lot of water intake.

I strongly recommend a full urinalysis and veterinary consult before giving antibiotics.

  • Ok, that is all very helpful. I've already been looking online for how to recognize different crystals, blood cells, etc, under the microscope. I guess the only thing I need to know is what kind of microscope to get and do I need a centrifuge also? Btw, I've also been checking specific gravity with a refractometer and most of it is very concentrated. 1.035 - 1.05. I started Feliway for the indoor cats. I'm finding none of the cats (outdoors and indoors) are drinking enough water. I might have to start with more rounds of wet food if they're just that stubborn.
    – Elorah
    Commented Aug 14, 2016 at 1:17
  • Well, that was all very good information, but I realized it didn't answer my original question. If I do find a legitimate infection (and don't necessarily want to do a culture and sensitivity the first time out), what are the correct guidelines for dosage and length of treatment with amoxicillin? (Unless there's another antibiotic you would recommend.)
    – Elorah
    Commented Aug 14, 2016 at 1:21
  • I can check dosing once I go back to work on Monday. The higher the concentration the better (means kidneys are functioning). I can check our brand of microscope but they are fairly expensive, you need at least 3 views, 10x, 40x and 100x + the 10x eye piece(s). 100x is for oil immersion and this setting you can identify abnormalities/types of bacteria within cells more accurately. Commented Aug 14, 2016 at 1:58
  • I recommend this site idexxlearningcenter.idexx.com/idexx/default.aspx You may have to cheat the system and pretend you're in the vet industry to create an account, but these lectures are all done by vets and techs and can help you a lot. We use this site to get credits to keep our license. Commented Aug 14, 2016 at 1:59

I know that most people don't recommend home treatment without a vet consultation, but the reason for that is not only the dosage amount, but the type of antibiotics given depend on the type of infection. Not to mention the fact it is tedious to get antibiotics without a prescription. But it is hard to justify a pricey vet bill when you already have what will be prescribed.

My cat came home a few times with a paw infection, and I gave him some of my own antibiotics-amoxicillin, the complete treatment took about 1 or 2 500 mg pills. The dosage is 5-10 mg per lb., and like humans, the first dose or two should be the maximum (10 mg per lb.) and then reduced to the minimum. This is to kill the majority of the infection and not lead to antibiotic resistance and then once that is accomplished the intent is not to strain the system by ingesting unnecessary amounts, but to maintain the resistance to the infection until it is gone.

Once the dose is reduced to the minimum it should be maintained until the cat is healthy again and a few days after just to make sure the infection has been eliminated. It is better to make sure it is gone that to resume treatment after an infection re-establishes. I administer half the dosage of 5 mg per lb twice a day (5 mg X 10 lbs= 50 mg per day; twice a day that means two doses of 25 mg) to make sure it is always in the system, just as recommended for humans, morning and evening doses. I wait for a few days or a week after the symptoms have disappeared, just like I would for myself. The whole treatment is usually two weeks or so. The most important thing is to wait until the cat seems healthy again and then keep giving the minimum dosage for a short time after that just to make sure.

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    welcome to the site. This is a good answer. I am concerned whether this question is a good fit for the site. Discussing medication dosing for pets, that should be prescribed by a vet. Please continue to contribute. :)
    – user6796
    Commented Apr 22, 2017 at 14:36
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    I know this answer has been accepted, but it is terrible medical advice. DO NOT GIVE HUMAN ANTIBIOTICS TO CATS in this way, and DO NOT TAPER them as described. This reflects a very poor understanding of antibiotic pharmacodynamics, which is exactly why vets are trained to know when and how to prescribe these medications.
    – Harry V.
    Commented Apr 22, 2017 at 18:04
  • Related Can I give my cat human medicine? Commented Apr 26, 2017 at 16:12

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