Horse Care Tips

Garlic: Good for Horses or Leaves a Bad Aftertaste?

garlic and horses
Written by Natalie Gasper

What’s the big stink?

Many horse owners prefer natural options for dealing with issues such as flies. While garlic is a non-chemical choice, is it a safe one?

Garlic, long considered a natural alternative with many benefits, has been proven to cause Heinz Body Anemia in horses. While some owners claim it’s an effective fly spray, there’s no proof that it actually works.

Until more research can be done, it may be best to look for other natural alternatives to garlic.

Garlic: The Great Debate

Equestrians are divided about feeding garlic for good reason. We’ll explore both the good and the bad of feeding your horse garlic.

Feeding Garlic: The Good

Garlic can have some benefits for horses.

Natural Fly Repellant (Rumored)

While many equestrians believe feeding garlic creates an odor in horse sweat that deters flies, there’s not much research to back this up.

flies on horses

Source: Canva

Does feeding garlic help with flies?

It doesn’t seem to. Other natural solutions include a mixture of apple cider vinegar, water, and various oils like citronella, lemongrass, and lavender.

Can you use garlic oil or liquid garlic as a topical fly repellent on horses?

Like with any spray, oil, or liquid, it could be absorbed through your horse’s skin. Too much garlic can create problems, so we’d suggest opting for a natural fly spray instead.

natural horse fly spray

Click to see it at Amazon

Antibacterial Properties

Thanks to allicin, garlic is known for being both antibacterial and antimicrobial.

Circulation/Respiratory Benefits

Garlic, which is high in organosulfur compounds, can help treat some respiratory issues by reducing mucus and easing coughs.

Feeding Garlic: The Bad

Garlic is a natural superfood, but it may not be safe for horses.

Heinz Body Anemia

Heinz Body Anemia is when the body breaks down red blood cells faster than it can replace them. In horses, the allium family (including onions and garlic) is to blame, thanks to the chemical N-propyl disulfide.

Can garlic hurt horses?

Yes, garlic can hurt horses. A condition called Heinz Body Anemia is the main concern. This condition can lead to decreased stamina, energy levels, and ability to fight disease.

Heinz Body Anemia can be caused by consuming more than just garlic—horses may display this anemia after eating maple leaves or wild onions, as well. Always check your pastures for potentially harmful plants, including wild onions and garlic.

garlic growing

Source: Canva

What are signs of garlic toxicity in horses?

Garlic toxicity can cause anemia, which isn’t always noticeable. Some signs include weakness, lethargy, loss of energy, pale gums, and loss of appetite.

Lack of Research

As of now, there are a limited number of studies on garlic and its effect on horses. Those that have been done indicate that garlic is likely not safe to feed because it can cause anemia.

horses and flies

Source: Canva

Until more research is conducted, we can’t recommend feeding garlic to horses at this time. If you’re looking for fly solutions, however, check out these two articles:

Frequently Asked Questions

Q: Is garlic safe for horses?

The jury is still out on this one. While some horses do okay with it, feeding too much can cause serious health problems. As always, consult your veterinarian!

Q: Is garlic good for horses’ breathing?

According to this article from PubMed Central, feeding garlic long-term can improve respiratory health. This same study also showed declines in several blood counts. As always, consult your veterinarian!

Q: Does garlic help horses with laminitis?

Because garlic can help reduce inflammation, many horse owners feed it to help with laminitis. Since garlic can cause anemia, Dr. Harman recommends feeding the coenzyme Q10, better known as CoQ10. As always, consult your veterinarian!

Q: Is garlic good for horses with sweet itch?

No! Garlic stimulates the immune system, which is already overactive in horses with sweet itch. Feeding flaxseed oil or apple cider vinegar, however, can help reduce the itching. As always, consult your veterinarian!

Parting Thoughts

When striving for natural alternatives for your horse, we recommend staying away from garlic until more research has been done.

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Further Reading

Garlic (Allium Sativum) Supplementation Improves Respiratory Health but Has Increased Risk of Lower Hematologic Values in Horses – PMC (

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About the author


Nancy loves retraining off the track Thoroughbreds and working with her dogs!