When cats lick their fur to clean up, they’re using a tool that’s better designed than your typical washcloth.
“Their tongue is actually like sandpaper,” Pitsko said. “They have tiny hooks called papillae. When they glide across the fur, it acts like a comb.”
So they de-tangle and remove mats in their fur as they bathe. The process also helps them stay comfortable, Pitsko said.
“They spread a natural oil that’s in their skin,” she said. “It kind of acts as an insulator and can keep them warm in the winter.”
In hot weather, spreading the saliva all over their coats helps them stay cool. As the saliva evaporates, it releases heat from the body. (Cats also sweat, but only through their paws.)
There’s also a social part of grooming.
“Cats will groom each other to show signs of affection,” Pitsko said. “Our big cats . . . they’re always grooming each other.”
So your cat really is telling you he likes you when he licks you, “unless you have something tasty on your hands,” she said.
As hunters, cats also wouldn’t want a scent on them that would let prey know they are approaching.
“If they have something really stinky on them, they’re going to have to get it off,” Pitsko said.
But she has also witnessed behavior that may disprove that theory.
“I’ve seen cats roll in things to make themselves stinky,” Pitsko said.
Usually, grooming is a good thing, but too much of it can be a sign of a stressed-out cat. Pitsko said zookeepers watch for bare spots on a lion’s or tiger’s coat, sometimes at the end of their tail. “That’s a sign that something’s wrong,” she said.
For a house cat, a similar bald patch would probably mean it’s time for a trip to the vet.
The vet might also want to stop a cat from licking after a surgery or because of a skin problem. Saliva has bacteria in it, but it also has proteins that have been shown to help wounds heal. Scientists don’t agree whether letting a cat lick a wound is better than keeping the bacteria away — often with the help of a cone around the cat’s head.
Lions and tigers at the zoo lick their wounds, Pitsko said. And those wounds typically heal on their own. Cones aren’t an option for these great cats.
“If they’re overdoing it, there’s a bad-tasting [substance] we can put on the area,” she said.
Zookeepers also sometimes have to take over lion- or tiger-cub grooming. Newborn cats can’t groom themselves, so their mothers perform the task, partly to encourage them to go to the bathroom. Last summer, a Sumatran tiger named Damai gave birth to a cub but soon stopped taking care of him.
“We would stimulate his bum with a cotton swab and warm water. Then make sure that he peed and pooped,” Pitsko said.
A few weeks of help from zookeepers did the trick. That cub started grooming himself and going to the bathroom on his own. He left Washington last fall to join an orphan Bengal tiger cub at the San Diego Zoo. So Rakan, as he is now known, has a buddy to play with and help keep him well groomed.