Letters 09/05: Garlic And Anemia

Found Anemic Horse
I read with great interest your article on anemia and feeding horses garlic. I feed both my horses (a 17.1-hand warmblood and a 14.1-hand Quarter Pony) one scoop, about an ounce of garlic every day. Though my dosage levels are far below the ones listed in your article, you mentioned there was no study on the effects of longterm use. My warmblood tires easily at horse shows compared to the pony, so I decided to have his blood tested.

Today I found out he’s borderline anemic. I will discontinue the supplement and retest him in the fall. I’m going to stop this supplement for the pony as well, though I doubt she’s anemic. I’ve learned through my children that they can be fed an almost identical diet and one will have iron at the top of the charts and the other can be wallowing at the bottom.

If my warmblood returns to normal levels by the fall, I plan to contact the manufacturer. Thank you for keeping me on my toes when it comes to my horses healthcare.

Georgette Topakas-Hicks

Your plan to discontinue and retest, with no other changes made, is a wise one, but we need to point out there are many possible causes of anemia, and many causes of easy tiring besides anemia. Since your pony is considerably smaller than your warmblood, a dose of garlic sufficient to cause anemia in the larger horse would likely do the same in the pony. Anemia related to garlic causes characteristic changes in the red blood cells. They develop tiny, bubble-like projections on their surface called Heinz bodies. If the anemia was truly related to garlic, microscopic examination of a smear made of your horse’s blood should reveal Heinz bodies. These are easiest to find if the microscope slide is made as soon as the blood sample is drawn.


Considers Study Skewed
Your article, “Garlic Causes Anemia” in your last issue was extremely irresponsible. Skewed studies like these are precisely why many people are turned off by scientific research and formal studies.

Over a cup (8.8 oz.) of garlic per day’ Are you kidding me’ Of course anything in excess will cause problems and, considering a normal dose for horses is one to two tablespoons per day, this is truly excessive and essentially this study mean nothing. I have never seen a recommendation by a horse-care professional, holistic or conventional, that suggests using even close to that amount.

Where is the study that would actually mean something’ Perhaps using the correct amount of garlic, one to two tablespoons a day’ Where is the article showing the wonderful benefits of garlic, which has, by the way, been used as a beneficial herb for 4,000 years.

Perhaps your article should have been titled “Over-dose of Garlic Causes Anemia” or “Improper Use of Garlic Causes Anemia.” I just hope this ridiculous article does not turn uninformed horse owners against this great feed addition.

Lisa Ross-Williams
Host of “If Your Horse Could Talk Show”

Our article stated the dosage of garlic that caused anemia, and that the effects of smaller amounts over longer periods were still unknown. Our bottom line also was clearly nothing more than caution is indicated. Unfortunately, the widespread impression that natural always means safe is not correct. Having been used for over 4,000 years as a human spice, “medicine,” and to ward off vampires doesn’t necessarily mean it is of any benefit to horses.

We can’t do an article on the benefits of garlic to horses for the simple reason that the evidence to support any simply isn’t there. Cholesterol-lowering and anticlotting effects have been documented for human patients, but horses don’t get atherosclerosis and coronary artery disease.

Otherwise, the only proven effect is a topical antibacterial/antifungal effect, i.e. killing organisms on direct contact at high concentration, not at all the same thing as eating it to get the same result.

As things now stand, without proof of effectiveness and with questions raised about safety, use of garlic looks like all-risk, no-benefit to us. All we said is that people feeding garlic should consider periodically checking for anemia. We stand by that statement. Garlic, and the onion, are documented to be toxic to small animals. We agree more studies, especially long-term studies at lower doses, are needed in horses, but the work done so far clearly confirms the same potential is there in the horse.

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