If you have ever been licked by a cat, the first thing you probably noticed was the rough texture of its tongue. Dogs have smooth tongues, whereas the texture of a cat's tongue is scratchy and rough, almost like sandpaper.
The centre of a cat's tongue is covered with small, backward-facing barbs or spines known as filiform papillae. These papillae contain keratin which is the same material human fingernails are made of, and this makes the papillae rigid. There are several reasons for cats having a rough tongue.
Cats are carnivores or meat-eaters. They hunt smaller animals as food. The most vital role in the wild would be that the spines on the tongue are used to help rasp and scrape flesh from the bones of their prey. Since the hooks are backward-facing, the papillae also help hold the prey in the cat's mouth. These barbs face toward the cat's throat and help push food in that direction for swallowing.
The cat's tongue also has fungiform (mushroom-shaped) papillae on the sides and tip and vallate papillae at the back, which hold the taste buds. Cats have relatively few taste buds compared to humans–470 in cats on average compared to 10,000 in the average human. A cat can sense both taste and texture with its tongue. Domestic and wild cats share a gene mutation that keeps their sweet taste buds from binding to sugary molecules, leaving them with no ability to taste sweetness. They are also relatively insensitive to salt. Their taste buds instead respond to amino acids and bitter tastes, and cats seem to be attracted to the texture of particular foods on the tongue instead.
Cats and many other animals have a Jacobson's organ located in their mouths that allows them to taste-smell certain aromas of which humans have no experience. They also have a distinct temperature preference for their food, preferring it with a temperature around 100�F (38 �C) which is similar to that of a fresh kill, rejecting food presented cold or refrigerated (which would signal to the cat that the "prey" item is long dead and therefore possibly toxic or decomposing). They use their tongues to test whether the food is too hot, too cold, or just right.
The taste buds of cats are also sensitive to the taste of water and it is important that your cat always has access to fresh, clean water. Unlike dogs that tend to slop water all over when they drink, cats are dainty drinkers because of the way they use their tongues. They form their tongues into small cup shapes when they lap up water.
The spines on a cat's tongue help it function as a built-in hairbrush or comb which can be used to groom the its fur. The tongue's rough texture is perfect for grooming. As the cat licks, loose hairs and other debris are caught on the barbs and removed from the coat. However, this can also lead to the formation of hairballs if you do not brush your pet often enough. Since the loose hairs are gathered by the barbs and directed toward the throat, the cat ends up swallowing the hairs. They collect in the stomach and form indigestible masses that can lead to blockages if the cat does not cough them back up. These clumps of hair are usually sausage-shaped and about two to three centimetres long. Hairballs can be prevented with remedies that ease elimination of the hair through the gut, as well as regular grooming of the coat with a comb or stiff brush. Some cats can develop a compulsive behaviour known as psychogenic alopecia, or excessive grooming.
Cats also use their tongues to cool off when grooming themselves. As they lick, the moisture left on the fur produces an evaporative cooling effect similar to sweating in humans. In addition to regulating body temperature, the saliva helps to keep the fur clean and smelling fresh.
Finally, cats use their tongues to show affection. When your cat licks you, she is showing you she cares for you, and this is a generous expression since many felines tend to be somewhat aloof.
Copyright � Kristel-Marie Ramnath 2016