Animal experts say that's because, unlike dogs, which as a species are more adapted to water, cats have not evolved to be comfortable in the water.
"Cats in the wild, they grow up hunting birds and mice, which are land animals," said animal behavior expert Rolan Tripp, founder of AnimalBehavior.net.
If cats have not been socialized to accept water at a very young age, they'll likely be frightened by the whole experience, he said.
He also said that, on average, felines are more fearful than canines because they've evolved as both prey and predator as opposed to just predator.
In their book, "Why Do Cats Always Land on Their Feet?" Becker and Gina Spadafori write that though domestic cats are descended from desert dwellers and seemingly have no desire to swim, they are perfectly good swimmers.
They also point out one breed of cat, Turkish vans, that like to swim and are even known as "The Swimming Cats" in some circles.
But for most felines, veterinarians caution against aquatic activities.
"Just on a routine basis, I don't recommend bathing cats," said Gary Norsworthy, owner of the Alamo Feline Health Center in San Antonio.
If they roll around in the dirt or in a pool of engine oil, or if they have a health issue, such as fleas or ringworm, then it might be time to ease them into a tub or sink, he said.
In those cases, he urges pet owners to spray the water into their hands and then on the cat, as opposed to hosing them down as one might a dog. Becker also recommends laying a towel on the floor of the tub or sink so that the surface isn't as slick under the cat's paws.
But for the most part, Norsworthy emphasized, cats do a pretty good job of keeping themselves clean on their own.
"Cats are like ovens," he said. "They're self-cleaning."