Do You Know How Much Garlic to Feed Horses?

March 10, 2023

Garlic is a powerful little plant. It has impressive healing, disease-inhibiting, and natural fly-repelling properties that can improve your horse’s health and quality of life. Garlic has been used for ages and is one of the most effective natural healing sources we know of. But can a horse eat too much garlic?

It's an important question often asked by horse owners researching or venturing into equine garlic supplementation. In this article, we'll discuss the powerful benefits of garlic for horses, the side effects of too much, and the right amount to feed for favorable results.

Is Garlic Safe for Horses?

Garlic is a potently aromatic bulb from the onion family. It’s been used for ages to flavor food, but also for medicinal purposes of both humans and animals. A quick internet search will provide pages of information (including this study by Oregon State University) about garlic's uses and benefits but may also raise questions about safety. Can horses have garlic? How much is safe to give? What are its benefits and risks? We have answers to help you feel comfortable and confident supplementing horses with garlic.

Benefits of Feeding Garlic to Horses

Garlic has impressive health-promoting capabilities and helps support a robust immune system. While additional research is needed to know all its uses and effects, here are some valuable benefits garlic may offer your horse:

• Helps treat and prevent lung diseases/infections
• Natural anti-inflammatory
• May assist with pain relief
• Lowers blood pressure
• Delivers antioxidant defense
• Improves gut health and flora
• Acts as an antibacterial/antimicrobial
• Helps keep flies off horses

Side Effects of Too Much Garlic 

Garlic touts a catalog of beneficial qualities, but some research has shown too much may be toxic to horses. Garlic contains N-propyl disulfide. It’s an element which, in high doses, can alter a horse’s red blood cells, causing Heinz body anemia. When the cells become damaged, the body removes them, and eventually your horse may develop anemia. It can happen quickly if horses eat wild garlic or onions growing in pastures, or slowly, due to over-supplementing.

Specifically, this National Library of Medicine study shows feeding more than 0.4 grams per kilogram body weight of freeze-dried garlic may cause Heinz body anemia in horses. That's the equivalent of feeding a 1,100-pound horse 200 or more grams per day, which is just under half a pound. That's a lot of garlic! While horses could easily eat that much in the wild, it's unlikely you'd feed such a large amount on purpose.

If you suspect your horse is consuming too much garlic—whether through supplementation or snacking on wild garlic—the Merck Vet Manual notes these symptoms of anemia may be present: 

• Loss of energy
• Weakness
• Loss of appetite
• Increased heart rate
• Pale gums
• Low blood pressure
• Jaundice

Garlic is contraindicated for horses with blood clotting problems or anemia. Giving horses a break by cycling on and off garlic can also reduce the risk of developing anemia.

Recommended Garlic Dose for Horses

Proper garlic supplementation can be done safely and will ensure your horse gets all the benefits without harmful side effects. So how much garlic should you feed a horse?

According to the National Research Council (2009), an average 1,100-pound horse can conservatively consume 7,500 milligrams, or 7.5 grams, of garlic per day. In these amounts, studies have shown garlic supplementation is safe, with little danger of horses developing anemia even if they consume garlic long term. You should consult your veterinarian before feeding garlic to ensure it's right for your horse, however, and always dose according to manufacturer's guidelines.

Redmond's Garlic Salt Supplement for Horses

Looking for a thoughtful garlic supplement and natural fly repellent for your horse? Redmond Rock Crushed Garlic is a safe and smart choice as a spring and summer fly control mineral sea salt. It contains bioidentical garlic oil—the most bioactive and stable form of garlic for horses—and 60+ mined trace minerals horses love.

Crushed Garlic does double duty keeping horses hydrated, healthy, and safer from disease-carrying pests. Feed it seasonally during spring and summer then switch to Redmond Daily Red or original Redmond Rock Crushed mineral salt during fall and winter to give your horse a garlic break. 

Crushed Garlic doses also align with the NRC’s safety guidelines. The table below shows how much product we recommend feeding a horse daily, the amount of garlic in each dose, and the garlic amounts the NRC suggests based on weight.

As you can see, Crushed with Garlic contains levels of garlic that fall within the NRC’s safety guidelines. So, reap the benefits! With Redmond, you can feel confident your horse is getting the health-promoting and pest-repelling properties of garlic in a natural mineral salt supplement, and doing it safely. Click below to try it today!

Learn More

• Garlic and spring go hand in hand! Get ready for the riding season with these 11 spring horse care tips.
• Is summer heat stressing your horse? Get professional vet tips for caring for horses in hot weather.

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