Cats should have approximately eight fluid ounces or 240 ml of water per day from food and drinking water. The kind of food your cat eats will determine how much additional water he will need to drink.
For example, a cat raw and canned foods contain approximately 70% water, dry food is only 10% water. Therefore a cat fed canned food will obtain more water from the diet than a cat on dry food. The cat who eats dry food will need to drink more water. Grams and ml are the same. So 200 grams of food would be the equivalent of 200 ml.
|Daily food requirements||Water content||Additional water required|
|Canned or raw food||200 g (100 g x two meals)||140 ml||100 ml|
|Dry food||75 g||7.5 ml||233 ml|
As you can see from the chart above, the cat on a canned or raw diet is getting more than half of his daily water requirements via his food, but the cat fed a dry diet needs to obtain almost all of his water by drinking. Not many cats will make up this shortfall by actually drinking water, and a common problem is that cats try to make up for this shortfall by conserving water, they do this by concentrating the urine. A knock on effect is that concentrated urine is the perfect environment for the formation of urinary crystals.
Water is essential for life. The cat’s body is approximately 60% water, and once that level drops by 5%, your cat will show signs of dehydration. Fluid is lost via the urine, feces respiration, and sweat (yes cats sweat, not as much as other mammals, but they do sweat via their paw pads).
Other factors which come into play:
- The size of your cat (obviously a 1kg kitten would drink less than a 5kg adult cat).
- The health of your cat – cats with kidney disease or hyperthyroidism drink more water.
- A pregnant or lactating queen.
- The current season, a cat will drink more water when it is warm.
- How much exercise your cat gets.
- Is the cat young and still nursing from his mother? Unweaned kittens get all the fluid (including water) they need via their mother’s milk, they do not need additional water until the weaning process begins from 4-5 weeks of age. Even then, kittens will continue to nurse from their mother.
How do I know if my cat is drinking enough water?
An easy way to check the hydration of your cat is to pull the skin behind your cat’s neck, in a young and well-hydrated cat, it will spring back immediately. If it is slow to go back, it could be a sign your cat is dehydrated. Other indicators are dry, sticky gums, sunken eyes and slow capillary refill time. To check this, pull your cat’s lip back, press firmly on the gum and remove your finger. The gum will be pale from the pressure you applied, see how quickly it takes for the gum to pink-up. The slower this takes, the more dehydrated your cat is.
How do I encourage my cat to drink more water?
- Make sure water bowls are clean and water should be emptied and refilled with clean, fresh drinking water daily.
- Feed more wet food.
- Try different types of water bowl. Plastic bowls can leech into the water, giving it an unpleasant taste to cats. Glass or ceramic bowls are better for your cat.
- Have multiple water bowls in the home.
- Switch to a water fountain; many cats prefer to drink from running water.
My kitten won’t drink water
Young kittens should only consume milk until they wean, and then they will begin to consume small amounts of water, but continue to nurse from their mother.
Once kittens are old enough to leave their mother and go to their new home, they should be drinking water. A kitten in a new home may initially refuse water, and it can take a few days for some kittens to settle in. Switch to wet food to increase water consumption. If the kitten appears to be lethargic, see a veterinarian as kittens can dehydrate quickly. The veterinarian can give him some fluids to correct his dehydration.
Why is my cat drinking more water than usual?
It is important to know your cat’s habits. Some cats naturally do drink more than others, but if you notice a change in behaviour and your cat is suddenly drinking more than usual (medically known as polydipsia) it could be a sign of the following:
- Diabetes mellitus – Either caused by insufficient insulin secretion or insulin resistance.
- Chronic or acute renal failure.
- Hyperthyroidism – Benign tumour of the thyroid gland which leads to the excess secretion of thyroid hormones.
- Pyometra – Infection of the uterus.
- Liver disease.
- Cushing’s disease (hyperadrenocorticism)
- Hypercalcemia (high blood calcium concentration)
- Acromegaly – Excess of growth hormone in an adult cat, most often caused by a growth hormone-secreting pituitary tumour.
- Hypokalemia – Abnormally low potassium concentration in the blood.
- Psychogenic polydipsia – Compulsive water drinking.
- Certain medications.