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Benefits of Oral Fluid Intake

Oral Fluid Requirements

Fluid Choices

Tips on Increasing Oral Fluid Intake (Including Water Fountains)

Rehydration Products

If Your Cat Stops Drinking

Feeding Tubes




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Home > Fluid Therapy > Oral Fluid Therapy



  • Oral fluids are the ideal way to maintain hydration.

  • This page has tips on helping your cat maintain his or her oral fluid intake.

  • Eventually CKD cats may need additional treatments, such as intravenous or subcutaneous fluids.

Benefits of Oral Fluid Intake


There is a saying in medicine: if the gut works, use it. Obviously this is particularly true of maintaining hydration, where it is a lot easier and less stressful for everyone if a cat takes in sufficient fluids orally and thus avoids the need for more proactive fluid management such as intravenous or subcutaneous fluids. This is also the most natural way for cats to take in fluids.


When we talk about oral fluid intake, we are not only referring to drinking. Cats obtain quite a lot of their fluid needs from the food they eat. Canned food contains about 80% water, so it is a good choice for a CKD cat.


Oral Fluid Requirements


In order to maintain hydration, a cat generally needs around 24-30ml of water per pound bodyweight per day (though this amount will be affected by activity levels and climate). This means that a 10lb (4.5kg) cat would require 240-300ml of water a day (a cat in congestive heart failure may need less).


Daily water requirements and needs for cats (2011) Peterson ME Animal Endocrine Clinic Blog says "A normal catís daily water requirement ranges from 5 to 10 fluid ounces per day (or an average of 60 ml/kg/day)."


The water requirements and drinking habits of cats (2018) Fritz J & Handl S Veterinary Focus 28(3) states that cats need about 50ml/kg per day, or 200-250ml a day for a 4-5kg cat.


The cat does not need to obtain this by drinking alone. If you are feeding canned food, which contains a lot of water, that will make a sizeable contribution to total intake.


Unfortunately, in older cats generally there can be a reduced thirst response, as mentioned in Senior cat care: special considerations for cats (2008). This may be the case even though CKD cats tend to need more fluids because they lose fluids through the increased urination caused by CKD.


Never restrict a CKD cat's access to water (unless your vet has advised you to do so for a brief period prior to surgery).


Fluid Choices


Some people give their cat bottled water. The taste of chlorine in normal tap water doesn't taste too good to cats, so this is worth considering but not essential.


Some people like to use distilled water, though I can't say I'm a fan. Some types of distilled water have a low pH level, and the extra acidity in these products is not appropriate for CKD cats, who tend towards acidity anyway. Distilled water may also cause potassium imbalances.


My cats' favourite water is rain water. Normally though we give them filtered water, at room temperature, and when we were using a bowl, we changed it several times a day (such frequent changes are not necessary with water fountains).


I would not recommend syringing the bags of fluid used for sub-Qs into your cat's mouth. Your cat is unlikely to accept these fluids orally because they taste salty and apparently rather oily. It is also far more expensive than giving ordinary water.


You should never try to inject ordinary water into your cat if you are giving sub-Qs because it is not the correct composition for injection; you should only use fluids approved for this purpose and prescribed by your vet.


Tips on Increasing Oral Fluid Intake


Cats generally are not known for drinking a lot, a legacy of their desert heritage. Therefore the more you can do to encourage them to increase their oral fluid intake, the better.


Cats in the wild do not eat and drink in the same place. Therefore it is better not to put the water bowl next to the food bowl. Some cats don't like a narrow bowl where their whiskers touch the side, so experiment, and also consider using a water fountain.


Some people find placing ice cubes made from low sodium tuna water in their cat's water bowl encourages their cat to drink more. You may also wish to give your cat homemade chicken broth to drink.


With a CKD cat, it makes a lot of sense to have more than one water source. We used to just have one bowl of water out but once Thomas was diagnosed we switched to three, including one placed upstairs so Thomas didn't have to go too far for a drink in the night.


You can also add water to your cat's food. One teaspoon of water is 5 ml, so if you can add 10 tsp a day to your cat's food, you are increasing fluid intake nicely. However, you do not want to overdo it, because if your cat takes in a lot of water, s/he could end up feeling quite full so calorie and nutrient intake reduce. Therefore aim to start slowly and make sure your cat still eats sufficient food.


If your cat is in mid-stage CKD and needs help with hydration but your vet refuses to allow you to give sub-Qs, you could consider syringing water into your cat's mouth instead. Discuss this possibility with your vet. You have to be careful because cats can only swallow a tiny amount at a time, and you should always syringe from the side of the mouth, never from the front - see syringe feeding for more information. Some people also use a water dropper. Don't give too much because if you do, your cat may feel full and then not eat enough.


Effects of feeding frequency on water intake in cats (2005) Kirschvink N, Lhoest E., Leemans J. Delvaux F, Istasse L, Gustin P, Diez M Journal of Veterinary Internal Medicine 19 p476 found that cats fed more frequently increased their fluid intake. Frequent feeding can also help with excess stomach acid.


Hill's explains why cats may prefer running water and gives tips on increasing your cat's water intake.


PetCoach has some tips on how to get your cat to drink more.


About Cats Online has tips on how to get your cat to drink.


Water Fountains

Many people find water fountains increase their cat's water intake. Effect of water source on intake and urine concentration in healthy cats (2010) Grant DC Journal of Feline Medicine and Surgery 12(6) pp431-4 found that cats drank a bit more from a water fountain but there was not a massive difference. This was a short study though.


Quantified water intake in laboratory cats from still, free-falling and circulating water bowls, and its effects on selected urinary parameters (2019) Robbins MT, Cline MG, Bartges JW, Felty E, Saker KE, Bastian R & Witzel AL Journal of Feline Medicine and Surgery 21(8) pp682-690 found that water intake did not differ significantly between the three methods, but three of the cats in the study (of fourteen cats) had a significant preference (one for still water, one for circulating and one for free-falling).


The water requirements and drinking habits of cats (2018) Fritz J & Handl S Veterinary Focus 28(3) states that cats need about 50ml/kg per day, or 200-250ml a day for a 4-5kg cat found that many cats seemed to prefer bowls, but concludes that offering cats a variety of drinking options may be helpful.


I found my cats needed time to get used to the fountain, but that they do like it and my personal scientific studies indicate that if you are a cat who lives with me, you do drink more if you have a free-falling water fountain. In fact, when the water fountain is in the dishwasher, we get indignant complaints until it is returned to its rightful place.


My cats have used the Fresh Flow brand for more than fifteen years and they love it (see photo left; I have no idea why Karma clambered over the tapestry frame rather than approaching it from the front or left, but hey, she's a cat and she has her reasons). Some people find the Catit easier to clean. Any of them should be fine for most cats.


When you first get a fountain, leave it out without water in for a few days to allow your cats to get used to it. Then add water, but don't turn it on. Once your cats are drinking from it, turn it on. Be sure to leave other water sources available until you know your cats are willing to use the fountain.


Instructables tells you how to build your own water fountain.


Sixerdoodle Electronics has instructions on using a sensor to turn a tap on when your cat approaches it:


There are several brands of water fountain available:

Water Fountains Sources



Amazon sells the Pioneer stainless steel model for US$53.99.


Glacier Point sells a variety of ceramic fountains.



Pet Planet sells a variety of water fountains.


Amazon UK sells a variety of water fountains.



Real Canadian Superstore sells the Petmate Freshflow Water Fountain in Western Canada for CAN$29.98.


Dino Direct sells freestanding water bottle holders, similar to the water supplies designed for hamsters etc. Some cats like this sort of fountain.


Oral Products for Rehydration

Normally a cat relying on oral fluid intake simply needs water. However, if a cat is clinically dehydrated, perhaps from vomiting or diarrhoea, s/he needs electrolytes (body salts) in addition to water. In such cases your vet may recommend oral rehydration sachets. My vet gave me some of these for use when my cat was recovering from dental surgery.


Some of these products contain additional zinc, so do not use without your vet's approval.


Veterinary Products



Pet-A-Lyte is a liquid electrolyte rehydration product. Drugs has some information about it.


Revival Animal Health sells Pet-A-Lyte.


Royal Canin Renal Liquid

Royal Canin sells a product called Renal Liquid in Europe. It contains 0.5% phosphorus on a dry matter analysis basis.



Oralade is a chicken-flavoured rehydration product available in Europe. It only seems to contain 0.65% phosphorus on a dry matter analysis basis, so might be worth considering if your cat is under par, perhaps with diarrhoea, or if your vet will not allow you to give sub-Qs.


VioVet sells Oratade.


Purina Hydra Care

Hydra care was launched in April 2020 as "a nutrient-enriched water containing osmolytes, which help cells absorb water."


According to Today's Veterinary Business, the liver-flavoured product is designed to be provided to cats in a third bowl, alongside a water and food bowl.


However, this product is designed for cats with a different type of problem (FLUTD), and is designed to lower urine specific gravity (USG). Therefore I do not think this product is suitable for CKD cats, who tend to have too low a USG anyway.


Human Rehydration Products


Pedialyte or Dioralyte

Pedialyte is a popular brand used in the USA, and is designed to rehydrate children with vomiting or diarrhoea.


Dioralyte is a similar popular which is popular in the UK


Only use the unflavoured variety of these products. Do not use without checking with your vet first, and be guided by him/her re dosage.


Vet Info discusses the use of Pedialyte in cats.


If Your Cat Stops Drinking


CKD cats who are not receiving sub-Qs regularly will drink a lot in an effort to keep themselves hydrated. I sometimes hear from people who are worried because their cat has started sub-Qs and is now hardly drinking at all. This is not normally something to worry about: cats who are receiving subcutaneous fluids regularly may drink much less, because some of their hydration needs are being met through the sub-Qs. 


Many CKD cats struggle with appetite, but they will usually continue to drink. Whether your cat is on sub-Qs or not, if s/he stops both drinking and eating, or if severe vomiting or diarrhoea or pancreatitis are present, it is possible that your cat is crashing or at the very least needs some veterinary support, so please contact your vet. Depending upon the situation, your vet may offer sub-Qs or intravenous fluids to help your cat through the crisis. The fluid that your vet uses in such situations is not only water, it also contains electrolytes (body salts) such as potassium, which may be lost in vomiting and diarrhoea.


You may well be able to stop giving sub-Qs once the crisis is over. Eventually, however, most CKD cats will not be able to drink take in enough fluid orally to maintain hydration, at which point they will probably need sub-Qs. In principle, this tends to happen when creatinine levels are consistently over 3.5-4.0 mg/dl (USA) or 300 -350 Ķmol/l (international).


Feeding Tubes


Feeding tubes are inserted for various reasons but one advantage of them is that you can give water (not the fluids usually used for sub-Qs) orally rather than having to give sub-Qs. Treatment recommendations for CKD in cats (2019) International Renal Interest Society state that feeding tubes should be considered for Stage 4 cats, for whom "Feeding tubes can be used to administer fluids as well as food."


ISFM consensus guidelines on the diagnosis and management of feline chronic kidney disease (2016) Sparkes AH, Caney S, Chalhoub S, Elliott J, Finch N, Gajanayake I, Langston C, Lefebvre H, White J & Quimby J Journal of Feline Medicine & Surgery 18 pp219-239 state "Water can also be administered via a feeding tube, and this may be preferable to subcutaneous fluids in many cases. A feeding tube is suitable for long-term maintenance of hydration and is a more physiological approach."




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This page last updated: 12 November 2020

Links on this page last checked: 02 July 2020







I have tried very hard to ensure that the information provided in this website is accurate, but I am NOT a vet, just an ordinary person who has lived through CKD with three cats. This website is for educational purposes only, and is not intended to be used to diagnose or treat any cat. Before trying any of the treatments described herein, you MUST consult a qualified veterinarian and obtain professional advice on the correct regimen for your cat and his or her particular requirements; and you should only use any treatments described here with the full knowledge and approval of your vet. No responsibility can be accepted.


If your cat appears to be in pain or distress, do not waste time on the internet, contact your vet immediately.



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