Cats Conserve Water: as everyone knows, cats are very good at concentrating their urine. This means that the because their kidneys evolved in a desert environment, every drop of water counts. Feline kidneys are fabulous at extracting water from the waste products that get filtered through them, and at ‘throwing out’ toxic substances left over from digestion and metabolism. Hence they are internally ‘recycling’ water constantly. Since muscle (meat protein) is their starting point (cats are strict carnivores - no vegetarians among them), cats throw out a lot more potassium than we do. Their kidneys are so efficient, that even if they become diabetics, in the early stages they do not drink extra water, so essentially they end up peeing out pure sugar (now THAT’S a picture!). Rather like Koalas, a cat hunting for a living rarely has to drink water - mice (and rats, rabbits and us!) are 80% water, at least their muscle and blood is - and there is not much fat on a mouse!
Lean muscle tissue contains about 75% water by weight. Blood contains almost 70% water, body fat contains 10% water and bone has 22% water. Skin also contains much water.Per Netter’s Atlas of Human Physiology quoted in Wikipedia.
Other species are considerably more profligate with their water usage - including all of us humans who drink tea, beer or soft drinks. One Green Point for the Cats there!
Cats are the Ultimate Energy Conservationists - and they do it by sleeping! Yes, studies have shown that cats (and other small strict carnivores like ferrets) expend a lot of energy capturing their prey, and they have to do it alone. It can take 3 attempts to catch a mouse, and cats need 10 mice per day. Cats also need to groom themselves, find a mate, feed young and all sorts of energy expending activities. Therefore, they use sleep (with its lower metabolic requirements) to conserve energy. Another Green Point. They do dream - of hunting mice of course!
And everyone knows - Cats are Solar Powered! So next time you see your cats snoozing in the sun - just think of them as Conserving Energy AND getting a solar-power recharge!