Cats & Water(Hydration)

"Water, however, is as vital to a cat’s survival as it is to that of humans. 60-70% of their body weight is water. Despite being good for them, many cats don’t like drinking water, especially if it’s still or standing water. This dislike for water can lead to a dehydrated cat, so it’s important to monitor your cat’s water intake."
https://www.purina.com/articles/cat/health/guide-to-cat-hydration

"Typical recommendations are that a cat requires about 50 mL of water per kg of bodyweight daily 3 – so this translates into 200-250 mL per day for a cat weighing 4-5 kg. This water requirement can be covered by the intake of “free water” from liquids and food, or from “oxidation water” produced by metabolism. This means that burning 1 g of protein, starch or fat yields just under 0.4 g, 0.6 g and 1.1 g of water respectively 4. The natural food of cats – i.e., prey such as small mammals and birds – contains about 70% moisture"
https://vetfocus.royalcanin.com/en/scientific/the-water-requirements-and-drinking-habits-of-cats

"The Committee on Nutrient Requirements of Dogs and Cats states that cats usually drink an ounce of water for every half-ounce of dry food ingested. Most veterinarians recommend that a normal, healthy cat drink about 4 ounces (about ½ cup) of water per 5 pounds of body weight per day."
https://www.petmd.com/cat/symptoms/why-your-cat-wont-drink-water-and-what-do

"Cats need to consume about 4 ounces of water per five pounds of lean body weight per day, so the average 10-pound cat should drink about one cup of water per day. It’s important to realize that cats that eat wet food, which can contain up to 80% water, may drink less, and cats that eat dry food usually take more of their daily water requirement in by drinking.

Signs of dehydration include lethargy, weakness, poor appetite, dry mucous membranes, and, in more severe cases, eyes that are sunken into their sockets."
https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/hydration