Ever since the children’s book Walter the Farting Dog hit bookstores in 2001, even the youngest members of our species know the truth. Dogs fart. They pass gas. Science-minded folk might refer to it as ‘flatus’ (not to be confused with flautas, which might or might not give you flatus). Whatever you call it, dog farts can be silent but deadly, they pop out of nowhere and can even be delivered in conjunction with a sneeze or a bark. In other words, dogs fart like us.

A recent study outperforms Walter the Farting Dog and really gives its researchers something to toot about. Researchers at the Waltham Center for Pet Nutrition in the UK designed a non-invasive technique to investigate dog flatulence in real-time. A special doggie jumpsuit with a tail-hole was designed to investigate the question, ‘What are stinky dog farts made of?’ This puts us on the path to our final destination, ‘How can we decrease the stink in dog farts?’

A dog fart suit

Capturing flatus should not be taken lightly. In the section, ‘Collection and analysis of rectal gases,’ the researchers describe the outfit they rigged up to assess dog farts in real-time. The main component is a jacket that looks similar to something companion dogs might wear in the rain, although this jacket comes with a sulfur-detecting pump attached to the area near the dog’s anus. To complete the suit, dogs wear disposable paper underpants to “protect the sampling device from external interference and help maintain proximity of the tubing to the anus.” Like I said, sort of like a rain jacket but with more farting.

What puts the stink in dog farts?

The researchers took their cue from human flatus which contains “the atmospheric gases nitrogen and oxygen plus the non-atmospheric gases carbon dioxide, hydrogen, and methane, also referred to as fermentation gases.” Sulfur gases, particularly hydrogen sulfide, are behind our visceral response of “EWWWWW! Who did THAT!?!” That smell is commonly associated with sulfur-rich foods, like cauliflower or broccoli (anybody else enjoyed these vegetables at Thanksgiving and then got on a plane?).

But back to dogs. To answer the question, “what’s in stinky dog farts?” the researchers took a two-pronged approach:

  • First, a fart suit measured what the dogs were dishing out, particularly hydrogen sulfide concentrations in parts per million.

  • Second, an Odor Judge was brought on board. Yes, someone was assigned to assess the odor of dog farts (and although the study does not spell it out, I presume the task was assigned using a highly advanced method of Rock-Paper-Scissors). The Odor Judge whiffed “each flatulence episode and rated the episode on a 1 to 5 scale, where 5 represented an unbearable odor and 1 was noise only with no odor. A rating of 2 represented a slightly noticeable odor, 3 was a mildly unpleasant odor, and 4 was a bad odor.” Ladies and gentlemen, I give you science. The assessment of the Odor Judge (who I hope wore a special sash or top hat) was then matched to the real-time reading from the dog fart suit to see what was in those distasteful farts.

Dogs are right there with their closest two-legged friends. As in humans, dog farts that rated higher on the “Eww” scale contained significantly more hydrogen sulfide than farts rated as less-noxious.

Since we are no longer subjects of the Roman emperor Claudius, who decreed that “all Roman citizens shall be allowed to pass gas whenever necessary” it is only reasonable to ask, “How can I decrease the stink in dog farts?”

Up next, Dog Farts Part 2: How to Make Dog Farts Less Stinky


Images: Featured Image, Warning Explosive Dog Farts, by CGP Gey; Girl & Dog, Nearby-Previously Unnoticed, by Gordon. Both via Flickr Creative Commons. Device to measure dog gas, Figure 1 in Collins et al. 2001 (below).


Collins et al. 2001. Development of a technique for the in vivo assessment of flatulence in dogs. American Journal of Veterinary Research. 62, 1014-1019.

Danzi, D. F. 1992. Flatology. The Journal of Emergency Medicine. 10, 79-88.