Water

Key points

Water is the most important and most often underestimated "ingredient" of the diet. It takes part in digestion, the transport of nutrients, temperature regulation, and kidney function. Without food the body will hold out for a long time, without water — for a very short time [1].

A raw diet is a lot of water

Raw meat, organ meats, and vegetables consist mostly of water — a typical BARF diet has about 65–75% moisture. For comparison, dry food usually has below 10%. This is why an animal fed raw gets a fair amount of water from the meal itself and drinks noticeably less than an animal on dry food [1] [2]. This is normal and not a cause for concern — the total water balance (from the bowl and from the food) is usually similar to or higher than with dry food.

Why it's especially important in cats

The cat descends from a desert ancestor and has a weak thirst reflex — drinking from the bowl, it often does not make up its entire water requirement. On dry food it is easy to have chronic, mild dehydration and concentrated urine, which favors lower urinary tract problems [1] [2]. A high-moisture diet — raw or wet — helps maintain dilute urine and supports the health of the cat's urinary system.

What to remember

Fresh water should always be available, regardless of diet. When feeding raw, less drinking from the bowl is expected. In cats, high diet moisture is a real benefit for the kidneys and bladder.

Sources

Merck Veterinary Manual. Nutritional Requirements of Small Animals. https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ (2010). Small Animal Clinical Nutrition, 5th Edition. https://www.markmorrisinstitute.org/sacn5.html