Or is there a quadraped that toots? I haven’t run across one, but then my experience is limited. Certainly the cats and dogs I’ve known all do the silent but deadly trick.
I haven’t heard it myself, but there’s anecdotal evidence that horses do.
May I congratulate you on the most perceptive and amazing question of the day. The week.
Mules fart so you can hear it. Basis of an old joke:
Q: Want some more oats, Mule?
A (Mule farts): FEW!
Are you kidding me??? I have heard my dogs fart as loudly and proudly as any man! And you haven’t been around horses much, have you? They fart loudly… it’s really pretty funny when they are gassy, riding at a trot. They fart with every stride at times!
EDIT: here is a short video of a farting horse:
Horses fart all the time, I would jokingly tell my students that it was “jet propulsion” to make 'em go faster. This, they found hilarious… then again, they were 10.
And then they look around like, ‘Whazzat? I heard something! Where is it? I know I heard something!’
My dog’s farts can be audible and then some. One day, we somehow thought it’d be a good idea to let her have a radish…four years later, we’re still telling each other that story.
No idea if cat farts are audible.
Sometimes, but it’s nothing compared to a dog or a horse!
Our 13-year-old Persian has been audible only a few times, but the cloud is almost visible and would gag a maggot.
It’s the look on her face afterwards that’s so cute! Almost a Cheshire Cat look.
One of my cats does, the other 2 are silent.
Cats make up for it with odor. It’s like getting hit in the face with a brick.
Sometimes I can poke at my cat’s belly, and he farts audibly.
Heh… one of my Setters sits very strraight and upright when begging, her tail straight out behind her. This puts her butthole flat against the tile floor. She has occasionally farted in this position, and it has whistled! 
She always snaps her head around with her ears up on top of her head with the most puzzled look on her face!
My dog scares himself with his farts. You hear “poot!” and he runs away.
Thank you everyone. I see that my animals are just sneakier than most. Also that this is another area in which humans are not unique.
Still, homo crepitus has a ring to it. (My only Latin is Google Latin, so feel free to correct.)
On the one occasion I heard my cat pass gas, it was a high-pitched, whistling squeak of a sound (like air escaping from a leaky balloon). I stared at her, thinking I can’t believe I just heard that sound coming from a cat! but Lucia was perfectly complacent and unembarrassed about the whole thing, as if she did it every day.
Cows can produce some solid-sounding booms as well, ime. I’ve heard what sounded like a symphony warming-up from a few herds before. Buffalo & ‘beefalo’ (hybridized), too.
The best (and funniest) I have ever heard was an elephant at OKC Zoo awhile back - that had all the kids falling down laughing almost to point of pissing their pants! :eek: A wall got sprayed with ‘bits’ so there was visual ‘evidence’ as well.
All you need for an audible fart is a semi-tensed anus and some pressurized gas. Quadruped possess these things, and as you’re finding out, they know how to use them.
Go to Youtube and search for “* fart”, where * is the animal of your choice, and you’ll find plenty of evidence. Example: “elephant fart”.
The opening paragraph of Ben Hur has the line about camels as “rude farting beasts”. I guess sensibilities were different 100 years ago. I assume most ruminants or grazers have gas issues (so to speak) because they rely on gut bacteria to break down the cellulose?
My dad likes to tell the story of the time he was at a reception with Richard Leaky, discoverer of the “Lucy” fossil, and taught him a new lesson in evolutionary biology. He pointed out that “due to bipedalism, did you know, man is the only animal that needs to wipe his arse?”
(Of course, sheep need to wipe their fur, but that’s nit-picking…)
A thought that’s occurred to me as well, I must admit.
I’ll bet sheep only have a problem from being bred by people to be efficient wool-producers, just as domestic turkeys have problems from being bred to produce more meat. I suspect that wild sheep don’t have this issue, as wild turkeys don’t have structural issues.