Why are cats' tongues designed like that?

Okay, it’s not strong enough to be pitted, so here we are in General Questions.

Why are cats’ tongues designed with the scratchy stuff pointed back instead of forwards?! Why is it designed to send the hair down their throats only to create mountains of potentially harmful hairballs?!

And if they are designed to send the hair down instead of out, why aren’t their digestive tracks equipped to handle such an onslaught of hair?! Why do we have to feed them slimy gook to help them process it?!

The hair can’t be digested so it must come out, either in the litter box or on your favorite pillow. Our cat got so compacted once that she had a dangerous and potentially brain-frying fever. The poor thing walked around funny for 2 days after that enema experience.

So, is there an evolutionary explanation for why this is or is it just poor design?

If the barbs were facing the other way, how could they groom themselves? Try it with your own tongue - it’s quite awkward.

As to why their bodies don’t deal better with hairballs, that is a mystery for the ages.

Their tongues are designed just fine. They act like little brushes to groom fur (wouldn’t work at all otherwise; just try combing your hair with the teeth facing backwards)… and I think they can use the bristles to scour little bits of meat off bones; at least the big cats can.

They cough up hairballs, and that’s about it. There will always be the occasional individual that has problems with any given system, such as a human tripping and falling because of that damn unstable bipedal system. But such occurances obviously haven’t caused extinction of the design, so it’s not really a problem. In the grand scheme of things nobody really cares about a hairball on your pillow, so there was never a reason to eliminate such an occurance.

My vet also told me that their tongues are designed not only for grooming, but also for stripping any remaining meat off the bone. I’m not sure how much a domestic cat would need that, but I guess it makes sense if you’re talking about a lion or something.

Hey, that’s just what my vet told me…

A cats tongue has isn’t designed that way to solely groom itself. It also serves to strip their kills of all the flesh, or so I seem to remember from a project on cats I did in elementary school. Similarly to hair going down so does all the yummy yummy mouse/antelope meat.

The hairball thing is weird, you’d think they would have got over that by now. Cats are notoriously lazy though. Maybe even in evolutionary terms.

Cats’ tongues eveloved naturally to help with their style of eating. Their fur is the unnatural result of centuries of breeding to produce useless poofy lap tyrants. I imagine that shorter-haired cats have less trouble with hairballs, yes?

I think hairballs depend upon the individual cat. Some cough 'em up more than others, regardless of the length (or lack thereof) of hair. My cats are both longhair/shorthair mixes. I think. I’m not really sure, 'cause I got them from the pound, and they weren’t sure what they were, but both cats have hair that’s a little too long to be shorthaired, and way too short to be longhaired. If that makes any sense. Anyway, they both groom a lot, even groom each other, but neither has problems with hairballs. I think they get them once every two or three months or so. Of course, now that I’ve said that I’ll probably step in one as soon as I leave my office. Yuck.

As others have said, it’s to rasp meat off the bones of prey… Lions, from what I understand, can take your skin off with one good lick.

An a different note… do big cats groom themselves like housecats?
I can’t recall ever seeing them doing it in a documentary.

Others have mentioned what jobs cats’ tongues do. But the real answer to this question is…

Cat’s tongues are like they are because the cats (or cat precursors) who had this particular type of tongue were the ones that survived. Evolution does not do anything intentionally
Why the cats with the barbed tongues survived and other cats did not is something that can of course be speculated on. But that speculation requires us to know whether there ever were any cats with tongues that looked differently. Perhaps most of the cat precursors had backward barbed tongues, and flat tongues died out in that animal.[/nitpick]

I will buy the stripping meat of the bone theory, and I know they need to groom and that the brittles *do * need to face backwards to accomplish this task. And it also seems that our long haired kitty, who grooms everyone else as well as herself, does have hairballs more frequently than others. But…

it still seems like their inability to digest hair is a rather significant design flaw. Now, I see your point that hairballs aren’t such a horrid problem as to cause extinction, but - to me - if there was something I did as a human on a daily basis that once, twice, or three times a month caused a negative (and annoying or possible painful) reaction like vomiting, I would think there was something wrong with the situation. Why would I continue doing the thing that caused the barfing? Or, like mmmiiikkkeee said, would it be insignificant enough that I didn’t care to change my ways? I can’t think of a human equivalent to this particular cat flaw just now, other than tripping maybe.

I have a 15-year old cat and as far as I remember, she has never once suffered from a furball, so I don’t think it’s a uniform problem.

Wow. Either she is hiding them, or I would love to know what kind of magic you are performing!


Look at the sea cucumber, which regularly vomits up its entire digestive system as a distraction when it’s under attack. Coughing up a hairball now and then, in comparison, doesn’t seem like that big a deal.

Ha! Could be… but am I knowingly doing something to make that happen? :slight_smile:

Yes, but this serves a purpose: protection. (Quite a feat!) But, a cat’s inability to digest hair and the hairball themselves seem to serve no purpose.

Yet the ability to cough up hairballs does: it gets the hair out of the digestive tract where it could otherwise clog. The hairballs themselves are just something that happens when you lick your fur with a raspy tongue (with the fur, the licking thereof, and the raspy tongue all being useful in themselves). The hacking up of them is the useful part.

Aww… that doesn’t seem fair. It doesn’t serve some higher purpose. Cats could do without hair in their systems altogether.

Why do cats, of all carnivores, need raspy tongues? Dogs do without them just fine.

Well, now that I think about it a bit more, the ability to cough them up could save them from sickness and possible death.

It’s not a matter of what they “need”, it’s a matter of what proved to be a good idea at the time. Dogs take the “gnaw the bone until it’s ground up enough to actually swallow” approach to getting the most out of their kills. Cats can’t do that, since they have very specialized carnassial teeth which don’t crunch bones well at all (but they slice meat very nicely). So, to get the last bits of meaty goodness off the bone, they lick it off. Just different solutions to a similar problem.

We’ve had two cats for a few years now and neither of them coughs up furballs. Not ever, as far as I can tell. However there are these facts to consider:[ol][li]They’re both short-hairs.[]They both shed a fair bit. Also, my wife brushes them regularly.[]We feed them canned food in addition to dry, which is supposed to give them more liquid and therefore help their digestion. Also, the fish oil in some of the canned food helps the fur pass through more easily.[/ol][/li]
This doesn’t address whether furball-vomiting is a common behavior in wild cats. I don’t really know, but my guess would be no, since this is essentially a kind of involuntary bulimia. It would be bad for the cat’s teeth and stomach, I assume, and would also mean losing whatever valuable food happened to be in the stomach at the time. Wild animals presumably can’t afford to pay these costs.

I’m guessing though about all this, as you can tell. Perhaps an authority on cat retching will come by and give a proper treatise.