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5x Why Your Dog’s Farts Smell Like Rotten Eggs & Sulfur

Why Do My Dog's Farts Smell Like Rotten Egg

Your dog’s fart can clear the room in two seconds flat!

That’s how bad it is. So you can’t help but cover your nose.

While farting is normal, the smell of your dog’s fart is out of this world.

You can’t help but ask yourself:

Why does my dog’s fart smell like rotten eggs and sulfur? How can I reduce the smell of my dog’s fart?

Good thing you found this article. Your dog’s smelly-fart days will be over.

Read on and discover:

  • 5 reasons why your dog’s farts smell like rotten eggs or sulfur.
  • 11 tips to eliminate horrible-smelling farts – or at least make the smell tolerable.
  • Sulfur-rich foods that you need to cut back on to eliminate your dog’s toxic farts.
  • What happens when your dog eats hard-to-digest foods, and why it leads to stinky farts.
  • And so much more…

Why do my dog’s farts smell like rotten eggs?

Your dog’s farts smell like rotten eggs due to their diet. Too much protein and cruciferous vegetables such as broccoli lead to stinky farts. That is mainly due to the sulfur content of these foods. Health conditions also make farts smell horrible, such as inflammatory bowel disease.

Why do my dog’s farts smell like sulfur?

Your dog’s farts smell like sulfur due to hydrogen sulfide. Typically, the majority of gases in a fart contains 5 odorless gases. The rest is made up of gases containing sulfur, such as hydrogen sulfide. This is what gives the sulfuric odor to farts.

5 reasons why your dog’s farts smell like rotten eggs or sulfur

#1: Too much protein or an indigestible diet

Are your dog’s toxic farts smelling like sulfur? That can be due to what your pooch eats.

Here’s a dog letting one rip while having a diva moment:

Let’s break down the smell of farts first.

Your dog’s fart doesn’t smell like roses. But you should be grateful if it doesn’t smell like anything.

When it happens, it’s thanks to the following gases:

  • Oxygen.
  • Nitrogen.
  • Methane.
  • Hydrogen.
  • Carbon dioxide.

These gases are odorless. They made up the majority of gases in a fart.

And the rest is made up of gases containing sulfur, such as hydrogen sulfide. This is what gives the smell of rotten eggs or sulfur to your dog’s toots.

Take note, sulfur has many benefits to one’s health. In fact, some amino acids have sulfur.


Too much sulfur can make farts stinky. 

This happens when your dog has too much protein or meat in their diet.


Sometimes we are not fully aware of what’s in the food our dog eats. What would help is checking the label of your dog’s food.

Do you see red meat, soybean meal, beans, peas, and eggs in the ingredients? These are foods rich in sulfur. And these are commonly used in commercial foods.

To make it worse, some dog parents feed their dogs table scraps such as greasy pork chops.

Also, dog food high in soy, wheat, and corn will make your dog’s fart stinky. That’s because these ingredients are hard to digest.

When dogs eat these, the colon’s normal bacteria have a hard time digesting. Two things come out of this:

One, the normal bacteria produce too much gas during digestion.

Two, the gas-producing bacteria take over and break down the indigestible foods.

High fiber and homemade dog foods

Foods high in fiber also make a dog’s toots smell bad.

Not only these, though. Some sulfur-rich foods will make your dog’s fart smelling like sulfur.

Such as cruciferous vegetables. These include broccoli, cabbage, kale, and cauliflower. 

In fact, you may have to go to another room after your dog farts. Because it’s going to smell horrible.

Low-quality dog food

Dogs eating low-quality food are more likely to keep farting. That’s due to the poorly digestible carbohydrates in the food.

Milk or dairy

Many dogs are lactose-intolerant. If yours is, they might suffer from an upset stomach and gas.

This is because the body is unable to digest lactose. What happens is that the gas-producing bacteria in the colon ferments lactose.

#2: Inflammatory bowel disease

Inflammatory Bowel Disease Causes Farts In Dogs

Having gas in the intestine is normal when a dog suffers from inflammatory bowel disease. But sometimes, it’s a very stinky gas.

What happens is that the small intestine can’t absorb the food. 

As a result, the undigested food travels to the colon. There, the bacteria digest the food and produce more gas in the process.

#3: Intestinal parasites

Your dog’s health can also affect how often they fart – and how smelly it is.

If they are not dewormed, and they have parasites, that could cause an upset stomach. And very stinky farts, too.

According to this study, Toxocara canis is the most prevalent parasite in dogs. Infection leads to flatulence, diarrhea, bloat, dehydration, and developmental delay.

#4: Exocrine pancreatic insufficiency (EPI)

In EPI, the pancreas doesn’t produce enough digestive enzymes.

Thus, the body cannot digest properly. 

This report listed the following symptoms of EPI:

  • Anorexia.
  • Vomiting.
  • Diarrhea.
  • Flatulence.
  • Stinky stools.
  • Poor hair coat.
  • Coprophagia (eating poop).
  • Pica (eating non-edible items).
  • Increased appetite but losing weight.

#5: Food allergies

Food allergies can cause your dog’s fart to smell like rotten eggs.

When dogs eat foods they’re allergic to, it will irritate their stomach. This leads to them farting every now and then.

According to this report, the following are the most common allergens:

  • Beef.
  • Lamb.
  • Dairy.
  • Wheat.
  • Chicken.

The less common allergens are:

  • Soy.
  • Fish.
  • Pork.
  • Rice.
  • Corn.
  • Eggs.

Note: A dog can be allergic to one or many of these. 

When they have an allergy, they may display one or many of these symptoms:

  • Diarrhea.
  • Itchy anus.
  • Chronic farting.
  • Licking their paws.
  • Intense itching on face and head.

You don’t have to stand around while dogs unleash their booty bombs. It’s time to find out how you can stop it.

That’s why I give you…

11 tips when your dog’s farts smell like rotten eggs or sulfur

#1: Give your dog high-quality food

“You are what you eat.”

I guess that applies to our canine pals as well. If they eat healthy foods, then you don’t have to worry about farts smelling horrible.

When choosing dog food, look for something that can be digested easily. As mentioned, indigestible foods are responsible for farts smelling like rotten eggs. 

That’s because the gas-producing bacteria break down indigestible food.

Give these bacteria a break by getting something easily digestible. There will be no undigested nutrients for bacteria to ferment.

Check out this RawRev dry dog food. This is an example of a digestible kibble. It’s even great for dogs with food sensitivities.

Remember: Look for “highly digestible” on the food label. If there’s none, consult with your vet about ingredients that can be digested easily.

#2: Provide enough protein in the diet

Provide Protein In Dog's Diet Against Smelly Farts

Whoever said that too much of something is bad, is saying the truth.

Dogs need protein in their diets. They need that for their body to function properly.

But only in the right amount.

Cut back on protein if your dog gets too much. You’ll do them a huge favor because they won’t be at risk of weight gain. 

And of course, there will be fewer chances of smelly gas.

#3: Feed your dog smaller meals

One of the reasons why dogs (and humans) fart is because they swallow a lot of air.

This happens when they eat too fast. It’s like they’re inhaling their food.

However, some dogs still swallow a lot of air. Take brachycephalic breeds for example. Because of their anatomy, they swallow a lot of air.

And in some cases, dogs with respiratory diseases do the same.

Add to that their consumption of sulfur-rich foods. They will be ripping farts that smell like rotten eggs.

Aside from feeding them high-quality food, do it in smaller meals a day. You can give them 3 or 4 small meals rather than 1 or 2 big meals.


If they eat once a day, they’d be hungry lions come mealtime. And because they’re famished, they’ll eat as fast as they could.

This won’t happen when they’re fed small meals.

#4: Get your dog to eat slow using this item

Slow feed your dog to prevent swallowing a lot of air.

Thankfully there are slow-feed dog bowls to help you. These are going to stop your dog from inhaling air with their food the moment you set the bowl down.

Check out this Outward Hound dog bowl. It will slow down your dog’s eating by up to 10 times.

And since dogs slow down eating, they can better digest what they eat. So it helps prevent bloating and obesity.

Here’s a dog mom who timed her dog eating in his normal bowl and in a slow feeder bowl.

It took him a minute and a half to finish eating in his normal bowl. Whereas it took him more than 5 minutes to lick his slow feeder bowl clean.

Let’s just hope your dog doesn’t get all smart and do this:

#5: Cut back on beans and cruciferous vegetables

There’s no harm feeding your dog sulfur-rich foods.

But the rule of thumb is to cut back on vegetables such as broccoli and beans.

Doing so will prevent your dog from being excessively gassy. And from having farts that smell like sulfur.

#6: Transition between diets gradually

Are you switching your dog’s food? 

Maybe your vet prescribed a new one. Or you decided to change to high-quality food.

Whatever it is, it’s not as simple as just giving your dog new food.

Changing your dog’s food should be gradual. Even if you’re switching to reduce your dog’s gassiness.

Did you know that drastic changes in their diet lead to them farting excessively? And depending on what you feed them, their farts could smell horrible.

That’s because drastic diet changes can upset stomachs. Your dog might vomit, lose appetite, or experience diarrhea.

So give their stomach time to get used to the new diet. Give it about a week.

The American Kennel Club (AKC) suggests the following transition:

Days 1-2: 25% new food + 75% old food.

Days 3-4: 50% new food + 50% old food.

Days 5-6: 75% new food + 25% old food.

Day 7: 100% new food.

Caution: Dogs with food allergies or gastrointestinal problems may need a longer transition. The rule of thumb is to monitor your dog’s response. Then transition more slowly if needed.

#7: Treat allergy

It’s a hassle when your dog has food allergies. These can give them foul-smelling farts.

If the bad odor didn’t go away after a while, take them to the vet. They will evaluate your dog for food allergies. 

They may also prescribe a hypoallergenic diet.

#8: Antibiotics

Some health problems are better left for vets to treat. Sometimes antibiotics are what your dog needs to treat excessive farting.

That said, bring your dog to the vet. And hopefully, when you stop giving antibiotics, their smelly farts will stop as well.

#9: Probiotics

Giving your dog probiotics can help a variety of digestive issues.

In this study, the authors wanted to find out how probiotics can affect inflammatory bowel disease (IBD).

They observed 34 dogs with IBD. Dogs were given standard therapy with or without probiotics.

Here’s what the findings showed:

Dogs with probiotic supplements showed increased levels of tight junction proteins. It suggests that probiotics may have beneficial effects. 

Probiotics come in different forms, such as:

  • Chews.
  • Powders.
  • Capsules.
  • Dog foods.
  • Yoghurt or kefir.

Note: If feeding your dog yogurt, go for the unsweetened, plain ones.

#10: Get your dog moving

Does your dog flop in one corner right after eating? Perhaps they love to lounge around more than go play and be active?

Vets will tell you that a sedentary lifestyle can make dogs fart more. Throw in other factors such as eating indigestible food and health problems.

You’ll have a dog farting up a storm every time.

So make sure your dog gets enough exercise everyday. Take them walking within 30 minutes after eating.

This helps them poop and eliminate gas.

#11: Get them charcoal dog biscuits

Here’s why I’ve included charcoal dog biscuits here:

In 2001, some scientists created a dog fart suit for an experiment

I kid you not!

Before you laugh, they actually used the suit to find out what dog fart is made of. And if the smell is manageable.

The suit, which looked like a dog coat, was non-invasive. There was a sulfur-sniffing part hanging over the dog’s bum.

So scientists outfitted 8 adult dogs with the suit. The dogs wore it for 14 hours daily for 4 days.

And while they go about their lives, the suit measured the farts for hydrogen sulfide.

Four days later, the scientists catalogued the farts. They ranked each fart from 1 to 5, 1 having no odor and 5 having “unbearable odour.”

They also found out a connection between hydrogen sulfide and the fart’s smelliness.

But the experiment didn’t end there. 

Thirty minutes after being fed their usual diet, the dogs were given treats.

But those were not ordinary treats. 

Some had activated charcoal. Others contained Yucca schidigera. And there were also ones with zinc acetate. 

There were treats incorporated with a combination of these three.

Here’s what scientists found out:

The three compounds effectively reduced the smelliness of the farts. Either individually or in combination. 

That’s because the compounds reduced the amount of hydrogen sulfide.


  • Charcoal reduced hydrogen sulfide by 71%.
  • Zinc acetate reduced hydrogen sulfide by 58%.
  • Yucca schidigera reduced hydrogen sulfide by 28%.

When the compounds were combined, the smelliness of farts decreased by 86%!

However, the compounds did not reduce the occurrence of farts. 

Warning: Consult with a vet before giving your dog supplements containing these compounds.