Featured ingredient part two: Water

How much water does your pet need?

The daily water requirement for any animal is defined as the amount of extra water required each day to maintain a stable body water balance for that animal. Your pet uses up a significant quantity of water each day in hydrolysis reactions, through losses during respiration, sweating through the mouth and the paws, and in the urine and faeces. These losses need to be replaced each day and this is achieved for the most part through the diet and from drinking free water. Eating and drinking account for about 90% of your pet’s daily water requirement. In addition, your pet also produces a significant quantity of water of his own when oxygen and hydrogen are combined as part of the energy- producing metabolic pathways. This ‘metabolic water’ accounts for up to 10% of your pet’s daily water requirement.

Oscar the Springer Spaniel and Nala the Pointer

So, how much water does this all add up to? Luckily, there is a reasonably accurate rule-of-thumb that states that any healthy animal needs to consume 1ml of water every day for every kilocalorie of energy it consumes, at rest and in an environment that is neither too hot, nor too cold, but just right, i.e. thermo-neutral. This can be put into an equation - ml/day = (70 x (body weight in kg)0.75) x 1.6.

This equation makes a lot of assumptions of course. Sick animals and especially animals that are vomiting and have diarrhoea need a lot more water, either through drinking, but more commonly straight into a vein if they are very unwell. Healthy dogs also need more water on days when they are busy and running about. The equation thus represents an absolute minimum daily water requirement – according to this equation, a 1 kg dog required 112 ml per day, a 4 kg cat required 317 ml / day and a 15 kg Spaniel requires 854 ml / day.

The nature of the pet’s diet determines how much fresh water he needs to drink each day, which may include from ponds, puddles etc. Pets on exclusively dry commercial food need to drink a lot more than those fed moist foods, which themselves consist of around 75% water.

From what has been said above, estimating daily water requirements for pets is really quite straightforward, but there are 1 or 2 other caveats that need to be taken into account. First, cats generally produce more concentrated urine than dogs, therefore they may need to drink a bit less water. Some pets drink over and above what they actually need because they simply enjoy it. This is fine as long as they do not do it to an excess. It is possible (but very rare) for an animal to drink so much in one go that it induces water intoxication which can be fatal.

And what about pets that don’t drink enough? Well, water losses of just 15% to 20% of total body weight is rapidly fatal, and this can happen in pets deprived of water completely over just a few days. Much more common are pets that don’t drink enough because of chronic illness, for example kidney disease. Cats are particularly susceptible to this. Other diseases in cats linked to not drinking enough include feline lower urinary tract disease (cystitis) and urolithiasis (bladder stones).

Dr. Robert Falconer-Taylor BVetMed DipCABT MRCVS

If you'd like bespoke advice from our Helpline experts, give us a call on 0800 195 8000 or email helpline@oscars.co.uk or contact us and we'll call you back.

Find Your Local Advisor

OSCAR Local Nutritional Advisors care for customers all over the UK. To find yours simply enter your postcode below:

Thanks for subscribing!

OSCAR News

OSCAR Rewarding Educational Success

Date: 24 Sep 2019

OSCAR Pet Foods takes pride in rewarding educational success at Myerscough College ....

Are You OSCAR's Longest-Standing Customer?!

Date: 02 Sep 2019

As OSCAR approaches 25 years of nutritional excellence we want to remember all the lovely pets ...

OSCAR Celebrate 25 Years of Nutritional Excellence

Date: 30 Aug 2019

At OSCAR Pet Foods we are thrilled to be celebrating twenty-five years of nutritional excellence

Nikki launches OSCAR Pet Foods Sutton Coldfield

Date: 23 Aug 2019

I made the decision to set up my own OSCAR business ...

July Pet Idol winner is ...

Date: 01 Aug 2019

And the winner of July's Pet Idol competition is ...

OSCAR Win Coveted Silver ‘Franchisor of the Year' Accolade

Date: 03 Jul 2019

OSCAR Pet Foods are thrilled to win a coveted Silver ‘Franchisor of the Year’ accolade ...

OSCAR Events

Elvaston Castle Christmas Craft Fair

Date: 23 Nov 2019

Elvaston Castle Christmas Craft Fair

Bridgnorth Christmas Market

Date: 08 Dec 2019

Bridgnorth Christmas Market


Oscar Footer Logos
All content is copyright Oscar ©2017. All rights reserved.