Why Do Dogs Eat Horse Poop? The Worm & Harm Factors

why do dogs eat horse poop

There’s nothing more stomach churning than going on a sedate country walk with your dog, only to turn back and see them chomping on something totally gross. My dog does this all the time and seems to have an unhealthy appetite for horse manure and poop!

This weird habit fascinates me, because there must be some reason dogs do it. If your dog also has a desire to eat horse droppings, I hope the guide below helps you. I’ve researched into what it could mean, what scientists say, and whether it’s bad or safe for your dog to eat horse poop, including the risk of worms!

But before I get into the detail, here’s the quick answer to why dogs eat horse manure and are so attracted to it.

Why do dogs eat horse poop? The reasons why dogs like to eat horse poop so much are wide and varied. The simplest answer is that they just like the smell and taste. However, some dogs will also chew droppings due to something missing in their diet or a health problem.

How common is it for dogs to eat horse poop?

Don’t think your dog is alone in having this gruesome habit. It’s actually quite a common condition and even comes with its own medical name; coprophagia (read Wikipedia definition).

In fact, in 2012, a researcher at the University of California said this regarding the findings of a study regarding coprophagia in dogs:

“The findings revealed that 16% of dogs sampled engaged in frequent conspecific coprophagy, defined as having been seen eating stools at least six times. Coprophagic dogs were more likely to be reported as greedy eaters than non‐coprophagic dogs. The coprophagy was overwhelmingly directed at fresh stools, defined as being no more than 2 days old..” (view study).

7 reasons why dogs eat horse poop

So, if you do have a dog who loves to eat horse poop, it’s not all the unusual, and it would appear that they prefer fresh manure too, rather than older poops! Below you can see all the possible reasons why your dog is eating horse dropping and then some advice on how you might be able to prevent it.

1. Horse poop tastes good!

Whilst our stomachs might turn at the thought of eating horse poop droppings, for dogs, it’s an amazing taste and treat – it makes sense when you think about it.

The feces of other animals will contain great tasting snacks and will also have a great smell and texture that far outweighs any thoughts your dog might have about it being poop.

It might smell bad to you, but to dogs, horse poop has a stink that will attract them from quite a distance so your dog will actively seek it out.

This is particularly true when you consider what horses like to eat; it’s things like grass, hay, fruit, vegetables, seeds, grass, grain, bulbs, and berries – all things you’ve probably seen your dog eat before.

Put those ingredients into one neat and smelly little poop package, and you have something that resembles a dog salad!

A dog’s sense of smell is said to be between 10,000 and 100,000 times better than ours. We have around 6 million smell receptors in our nose, dogs have around 300 million… so just think how appealing that horse poop must smell to a dog!

Handy Hint: Dogs love this stuff so much they will also try rolling in it! Here are some theories on why dogs roll in horse poop for you to consider.

2. To protect their pack

Dogs are said to still have many instincts left over from the ancestral days of being wolves and wild dogs, and this relates to the next possibility: Dogs like to eat horse poop as a way to protect their pack and younger relations.

This is referenced in the 2012 study I linked to earlier, with the following statement published with the research:

“A hypothesis is offered that coprophagy reflects a tendency inherited from the ancestral wolf to keep the den area free of faecal‐borne intestinal parasites that might be deposited in the den resting area and would typically have parasite ova that are not initially infective, but could develop infective larvae after 2 days. An evolved parasite defence strategy to consume fresh faeces in the rest area would be adaptive.”

When I read that, my view is that we have to seriously consider that horse poop consumption is simply part of your dog’s DNA relating to how they would have behaved in days gone by.

3. As investigative and scavenging behavior

Younger dogs and puppies will eat horse poop as way of investigating things. They are very similar to how human babies will want to put things in their mouth to see what they are, and puppies are the same.

There is also an element of scavenging behavior where puppies will often worry about where their next meal is coming from, trying to eat everything in sight before it gets taken away.

4. To replace nutrients or an enzyme deficiency

Dogs also like to eat horse poop and manure due to deficiencies in their diet. This can include things like a lack of nutrients or enzymes.

horse poop dog
Here’s my dog sniffing out some fresh horse dung and droppings to have a chew on!

The reason this makes them eat horse manure is down to what the horses themselves eat. They will have a diet that is rich in enzymes and partially digested proteins because of what they graze on. Not all dogs get these elements into their system, so their body will seek it out elsewhere.

It’s not an uncommon occurrence in the animal kingdom. For example, the American Kennel Club say this on their website on the topic:

“For some species, such as rabbits, eating fecal droppings is a totally normal way of obtaining key nutrients. In fact, if you prevent rabbits from doing this, they will develop health problems, and young ones will fail to thrive.”

Domestic dogs will also have this instinct which has developed over thousands of years of evolution.

5. To self-medicate themselves

Dogs will also turn to eating horse poop to make themselves feel better as a way of self-medication.

For example, dogs with parasites will often turn to poop to try to medicate themselves. Parasites will leach nutrients from your dog, and your dog might think it can replace those nutrients via horse poop, which will often be high in it.

6. Horse manure can look like a tasty treat

Once horse poop is all dried up and broken apart it can resemble certain dog snacks. No wonder it’s so appealing to eat!

Dogs are so food-orientated that once they lock on to the smell of horse poop then see some on the ground, it’s going to be very hard to convince them that’s it’s not a tasty dog treat. You can’t blame them for wanting to have a chew on the manure despite how gross it looks to us!

7. Your dog is just hungry

And finally, it might be just because your dog is hungry. Before you go anywhere with your dog where the chance of eating horse poop is high, make sure they’ve had a meal, or you take some alternative snacks with you.

Is it safe for dogs to eat horse poop?

This is a hard one to answer, because most of the time it will not be bad for your dog to eat a little bit of horse manure, and they should not suffer any adverse reactions. There’s nothing naturally occurring in horse poop that is toxic to dogs (view source).

However, there are still some risks, and I will start off with the one that is most alarming; ivermectin poisoning.

Ivermectin poisoning

Ivermectin is a chemical found in worming treatment medicine given to horses. Scientists have found that ivermectin can stay in horse manure for up to 45 days after the worm treatment is administered.

If your dog eats horse manure, then it could hurt them. There is this small risk, and according to the UK animal charity, the Blue Cross, here’s what to consider:

“Small amounts of ivermectin pose a health threat to some breeds but most dogs will not be affected. Symptoms of ivermectin poisoning include dilated pupils, disorientation, lethargy and vomiting. Dogs showing any of these signs or known to be at risk should be seen by a vet immediately.”

Whilst it appears that the risk is low, it’s still important to consider. If your dog has diarrhea after eating horse poop then this could be the reason why, so get in touch with a vet immediately.

The Blue Cross go on to say that certain dog breeds are more at risk from eating horse manure:

“Any dog that consumes a large amount of horse poop containing the chemical could become very ill, but a percentage of dogs of certain breeds have a gene mutation which predisposes them to toxicity from ivermectin at low levels. These include collies, Shetland sheepdogs, Australian shepherds, Old English sheepdogs, long-haired whippets, merle Pomeranians and possibly other herding breeds as well as those with white feet.”

Can my dog get worms from eating horse poop?

There’s also the consideration that your dog could get worms from eating horse poop. For example, if the horse is not up to date with its worm treatment, those parasites could pass through the manure which is then ingested by a greedy dog. So yes, dogs can get worms from horse poop.

As well as possible ivermectin poisoning, there are other small risks that could mean eating horse poop is bad for your dog.

Other risks of harm

For example, there can be traces of salmonella and campylobacter in horse feces. Admittedly that sounds bad, but dogs are said to have quite robust gastrointestinal tracts, so infections are said to be few and far between.

You should also be wary when you see holes and flies around the horse poop. This could be a sign that there are parasites in the manure droppings which could lead to a bacterial infection.

The bottom line is this; I would try to stop my dog from eating horse poop as much as possible. Whilst statistically speaking the chances of them getting ill after eating a small bit of manure is slim, there is always a chance it could lead to a problem.

You certainly need to take action if your dog likes to eat horse manure. Stop it happening as soon as you can, and here are some tips on how to do so.

How to stop your dog eating horse poop

You will have already considered stopping going to walks where you might encounter lots of horse manure. It might not always be possible to avoid it completely though, so here are some short tips you could consider:

  • Improve your dog’s diet: Your dog might be chewing the poop due to a nutritional deficiency, so make sure you change the diet appropriately.
  • Keep the animals apart: If you keep horses, don’t let them run free in the same area that your dog has access to.
  • Contaminate the poop: Horses owners can also try sprinkling cayenne pepper or similar onto the poop to turn your dog off. After a few days, the dog should get the message.

And above all, if the poop eating becomes problematic then it could be sign of health issue such as parasites so you should seek a professional intervention.

When to call a vet

If you have any concerns, you should always consult with a vet. The notes in this guide are written by me, a dog lover and not a veterinary professional – everything you read here is based on my own online research and opinion.

What I would say is this though; if your dog’s poop eating appears to be problematic and way to regular to be dismissed, you should call your vet.


Everything in this guide is based on my personal opinion and research. You should always do your own due diligence when it comes to things like this and see if you agree that a little horse poop probably won’t harm your dog in most cases.

However, if it’s regular and in volume then it certainly is something you need to put a stop to reduce the chance of your dog coming to harm.

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I spend a lot of time in our local forest walking my dog, and he’s eaten and rolled in a lot of gross stuff… some of which I’ve investigated!

Marc Aaron

I write about the things we've learned about owning dogs, the adventures we have, and any advice and tips we've picked up along the way.

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