You’re happily petting the sweet furry, when your friend looks somewhat extra beatific. And then, two seconds later, you’re hit by a smell that’s just pure sewer drain. Let’s face it: dogs are sweet but when they let fly a toot, oh boy.

My three cats are either awfully discrete or perfectly regulated, so when I was hit with a noxious cloud the other day by a canine pal, I went delving into the how’s and why’s. What I discovered fascinated me.

How farts happen is a simple concept. Basically, we swallow air all the time, when we’re eating, drinking or just breathing. It has to exit the body so it either comes up again as burps or goes out the other end.

If it goes south, it mixes with the flatus (a posh word for toots) that is the by-product of digestion. The distinctive nasty smell is down to gases like hydrogen sulphide, the stuff that smells like rotten eggs.

Curiously, you can tell if a dog is going to be tooting a lot by looking at its face. As swallowing air is a factor, a flat-faced doggy that snorts a lot, like a Pug or a Shih Tzu, will likely be airier than the pointy-nosed clear-breathing Pointers and Dachshunds.


All dogs fart but pets that have trouble digesting their food can end up being flatulent. Photo:

The smell that goes with it, is often down to diet. All dogs fart but when pets are having trouble digesting their food, you can end up with an over-gassy pet. Dogs are carnivores by nature so, while they can usually deal with a little veg in their diet, you might want to avoid pet food that is high in soy, wheat and corn as these are hard to digest.

Surprisingly, a lot of dogs are also lactose intolerant. So if you’re into the classic bread-soaked-in-milk breakfast for your pet, this may be causing upset tummies and gas.

Also, while dogs will happily snarf our leftovers, it inevitably means consuming things that really aren’t good for dogs. This includes no-no foods like grapes, raisins and onions as well as apparently “okay” ingredients like coconut oil that can act as laxatives.

Overall physical health is a factor, too. If your pet hasn’t been properly dewormed, that might be the cause of the bad smell and upset tummy. It’s important, therefore, to keep up a proper deworming schedule, even if your dog is a mostly indoor pet.

However, the bottom line is that flatus is a natural phenomenon, and so all healthy dogs will be giving off “air biscuits”.

Interestingly, animal farts are a hot topic of research. If you check Twitter for the tag #DoesItFart, you’ll quickly find that scientists are researching the subject in order to understand climate change better.

In a fascinating spreadsheet that rates all kinds of animals, Burmese python farts are described as “silent but deadly” and bobcat observers have remarked, “Squirrel-based farts are the worst.”


Squirrels, cute as they are, supposedly have the worst farts Photo: StockSnap

The apple for most dedicated scientists, however, has to go to Britain’s Waltham Centre for Pet Nutrition. Back in 2000, their staff went all out to set up an experiment that has become a byword for weird and wonderful science. Their aim was to discover exactly what dog flatus was composed of, and whether the smell could be managed.

First of all, the centre designed a canine flatus-analysing suit. They wanted something kind and non-invasive, so they came up with a dog coat with a sulphur-sniffing attachment that hung over the dog’s bottom.

I’m not kidding; this is a real thing.

Once they were certain the coats were comfy, they fitted them on eight adult dogs. These pets wore the coats for 14 hours every day for four days. As the dogs went about their daily routines, the attachments measured the gases exiting the dog for hydrogen sulphide content every 20 seconds.

At the end of the experiment, they found significant differences in the amount that each doggy farted, and the smelliness of these gases. Being thoroughly dedicated, the scientists sniffed and catalogued the flatus, ranking 1 as “no odour” all the way up to 4 meaning “bad odour” and 5 as “unbearable odour”. Analysis showed a very reliable connection between hydrogen sulphide and smelliness.

Then came the clever part. The dogs were fed as normal but were then given doggy treats some 30 minutes after their meals. Some of these treats contained activated charcoal, Yucca schidigera or zinc acetate, while others were plain old treats.

In blind-study tradition, the scientists weren’t told which dog had the doctored treats. They were simply told to keep sniffing and rating the flatus. What a job, right? It must have been the centre of some wild dinner party discussions!

Anyway, when it came to the sniff tests, all three compounds were effective in lowering the smelliness of the flatus.

Taking it one step further, they analysed fresh doggy droppings. They found that the charcoal reduced hydrogen sulphide given off by 71%, the zinc acetate by 58% and the Yucca schidigera by 38%. When dog treats with all three compounds were handed out, the smelly factor was decreased by an astounding 86%.

So there you go. If your pet is a little pungent, buy some charcoal dog biscuits as a treat. You’ll be doing yourself a favour!

An Unhappy Pet Can Have Digestion Issues

While farts are the by-product of a normal healthy working body, there is a psychological factor at work, too. When we are unhappy, our digestion often suffers. We get rumbly tummies, the things we normally eat just don’t go down well, and we’re in and out of the loo.

Dogs are exactly the same. If your pet is unhappy, you can expect to see just the same effects as you would in a small child. As such, it’s vital that you provide the proper emotional environment for your pet.

1. Loving companionship is key. Dogs are social and you are the centre of their universe. So spend time with your pet every single day. Don’t lock them out in the garden; spend time talking to them. When you’re watching TV, let your pet watch with you.

2. Exercise is a major part of your dog’s day. That walk around the block isn’t just about going for a wee, it’s about being with you, and catching up with the world. Your pet sniffs about in order to catch up with who’s been around, who’s doing what, and more. So walk with joy. Take your time, and don’t yank the leash.

3. Stop beating your dog. Communicating with a pet should never involve violence. If your pet doesn’t understand you, be the responsible adult and work it out. You wouldn’t like to be thrashed for making a mistake, so don’t do it to them. If you carry a cane, break the dratted thing and throw it away.

Finally, be grateful. If you think your dog is a major farter, take a look at the humble termite. These little insects are champion gas producers, with some scientists calculating they may produce as much as 11% of all global methane emissions.