Ask Horse Journal: 04/07

I have a 26-year-old mare who has severe thrush, which I’ve been trying to treat with over-the-counter medications without success. My farrier recommended that I spray the infected area with bleach, but it didn’t work either. I heard that Sugardine is a great home remedy to help with thrush and wound care on horses as well as in humans. Could you please advise me if this is true or if it’s just another treatment that doesn’t work’

Horse Journal Response

Sugardine (a mixture of plain table sugar and Betadine) can be effective in clearing thrush. It’s highly antibacterial but also relatively gentle to the tissues, although the iodine in the Betadine does cause some drying.

It’s important to make sure the infected area is exposed to air by keeping the feet and frogs well trimmed. Gently clean the feet to be sure you don’t irritate the tissues or drive the infection even deeper.

A mixture of 4 parts sugar to 1 part Betadine will make a Sugardine paste that you can pack into the area. Since you want to keep the pack in place and keep her feet away from dirt, manure and dampness, we recommend you put a hoof boot on her to hold it all in place. Repack daily until the area is clear of thrush.

Estrone For Geldings

I was told by a veterinarian on the A hunter circuit that I should think about giving my horse injections of Estrone. He told me that this hormone will help maintain healthy joint cartilage in geldings, since they no longer have their testes, which would produce estrogen in male horses. I know a lot of people use this product with their geldings. Could you enlighten me about the value and mechanics of Estrone (estrogen) in male horses’

Horse Journal Response

Geldings do produce estrogen (in their adrenal glands), just not as much as stallions. Estrone is often recommended for geldings with stifle problems. It helps, although it’s not clear why, since the effect of estrogen on ligaments seem to be to make them looser. Estrogen is an anti-inflammatory hormone, but if estrogen was a major determinant of joint health, we should see more arthritis in geldings than in mares and stallions. We don’t.

Estrogen is often used in geldings as a milder form of an anabolic tissue-building hormone. Geldings on estrogen are usually more alert, build muscle well, eat well and have more of a happy, enthusiastic attitude than geldings on other types of anabolics, which mimic male hormones and may make them more aggressive.

As for arthritis, cartilage repair and growth may be influenced by estrogen. Basically, we see the reasoning behind your veterinarian’s thinking, but we can’t say for sure that Estrone injections will really help protect joints in gelded horses. 

Founder And Lyme

Is an insulin-resistant horse more likely to founder if he has untreated Lyme disease’

Horse Journal Response

Yes, Lyme may be associated with laminitis in horses, but whether this involves creating an insulin-resistant state or not is unknown. Horses that are already insulin-resistant, or prone to it, might be more likely to become laminitic, but the details are unclear. However, regardless of whether there’s a direct connection between insulin resistance and Lyme, both do seem to be clear risk factors for laminitis. As risk factors accumulate, the odds of laminitis become more favorable.

Fat In Flaxseed

Is ground flaxseed an adequate source of fat for appropriate absorption of vitamin E’

Horse Journal Response

Yes, ground stabilized flaxseed is an excellent source of fat. Feed your vitamin E with the flax (for more information on vitamin E supplementation, see January 2007).


My seven-year-old Quarter Horse mare has always had a slightly cresty neck, but I’d been able to control her weight until this past year. My riding time was limited, and she spent most of the summer on pasture. I stopped all grain and put her on a vitamin supplement with free-choice minerals. No real weight loss. My vet took blood and said her thyroid was normal, but her insulin was 119 (normal range was 2-25). I purchased a grazing muzzle for when she’s out at night and keep her in during the day. She started on chromium, per my vet, and has lost some weight and her blood-insulin level is lower than it was but still too high. I’ve also added magnesium to her diet and am exercising her. Most of my supplements are in powder form, which is hard for me to feed without grain because my mare doesn’t like beet pulp.

Can you tell me where I can get what the NRC (National Research Council) recommendations for minerals’ I’m thinking about changing supplements. Thanks for any recommendations.

Horse Journal Response

You’ll have better results overall if you include the most important step in gaining control of an insulin-resistant horse: Control the amount of simple carbohydrate in her diet to a low-enough level. Grass and most grass hays are too high for insulin-resistant horses. Muzzling is good, but if she can still get grass through it, it’s not good enough. You need to know what your hay’s sugar and starch levels are, as well as the minerals. Once you know what minerals have to be added, you can add only those and skip all the guess work.

The NRC Nutrient Requirements for Horses can be found on line at:

Chapter 5 will give you the minimum requirements for calcium and phosphorus by weight of the horse. Set your magnesium requirement to half the amount of calcium. For trace minerals, we suggest the following as a starting point. Compare these to levels on your hay:

Copper 15 ppm (1 ppm = 1 mg per kg of hay)

Zinc 45 ppm

Manganese 37.5 ppm

Selenium 0.15 ppm

To make the math easy, 22 lbs. of hay = 10 kg, a fairly common amount for a full size horse in a hay based diet. For every 22 lbs. of hay your horse eats, multiply the results of the analysis by 10 to get daily intake. For example, if your hay analysis shows 6 ppm of copper, your horse will get 60 mg in 22 lbs.

Questioning Chromium

I have a 13-year-old Shetland pony that was diagnosed with insulin resistance. Since I have close ties to this subject, I study the articles in Horse Journal religiously. In the past few years, I have found your information keeps changing about the ways to prevent/reduce the effects of insulin resistance. I find the discrepancies in the various articles confusing and would like to know why the contradictions in articles’ Could you please recommend what you think is the best nutritional plan for my pony’

Horse Journal Response

Since our earliest articles regarding minerals and insulin resistance, Dr. Eleanor Kellon has managed the diets of hundreds of insulin-resistant horses and re viewed several hundred hay analyses from across the country. For that reason, we continue to update you on the latest recommendations based upon her experience and the most recent studies.

For example, a review of soil chromium levels across the country found all were from adequate to considerably above adequate, and plants take up chromium readily except for very alkaline soils, such as those in the Southwest. Research has also failed to show any influence of chromium on insulin sensitivity per se. We therefore don’t currently recommend chromium supplementation, although we did at one time.

Our first magnesium recommendation was for a level that appeared to be of benefit but was safe from the standpoint of not introducing magnesium excess into the diet. Our most recent recommendation of 5 grams/day is only for short-term use and is based on examining hundreds of hay analyses. Frankly, the addition of magnesium should be based on knowing what is actually in your horse’s hay to begin with. Some hays don’t need any additional magnesium added to the diet.

We now include 1 oz. minimum/day of iodized table salt in our recommendations. If you feed your horse iodized table salt, you won’t have to add more supplemental iodine. We work to offer you the most up-to-date information available.

For your pony, the simplest approach is to use a commercially available low NSC diet feed, with additions as detailed in our December 2006 article. Flax, vitamin E and iodized salt round out the basic diet.

Tapering Jiaogulan

Once my mare had hives, and I gave the vet the Horse Journal article on Spirulina to read. After she emailed your veterinary editor, Dr. Eleanor Kellon, my vet was able to help 10 other horses with the same problem. The last time my mare had a mild case of laminitis, we were lucky to catch it quickly, Dr. Kellon suggested using Gynostemma (Jiaogulan) for six months. I have, and now I’d like to know how to taper off the dose. Horse Journal has been so good to me. I have told all of my horse friends about your publication and all the help it provides horse owners.

Horse Journal Response

If the horse has been free of laminitis symptoms for several months, you can simply stop giving the Jiaogulan. However, if you want to observe her response rather than simply stopping it, cut the dose in half for two weeks, then in half again for another two weeks, then stop. Many owners find their horses, especially older horses, seem to feel so much better on the Jiaogulan that they decide to continue them on it even when the foot problems are solved.

Cushing’s Meds

My horse is on Pergolide for Cushing’s, and I want to stop giving it. I’m trying to make the diet adjustments you’ve suggested in Horse Journal, but I can’t find beet pulp without molasses. Can I stop the Pergolide and just manage him through diet’ I have some pelleted beet pulp, but it contains molasses. Is this a problem’

Horse Journal Response

If your horse has confirmed Cushing’s, don’t take him off the Pergolide. As for molasses in the beet pulp, you need to find out from your vet if your horse is also insulin resistant. Not all Cushing’s horses are insulin-resistant. If your horse is not, the molasses isn’t as much of an issue. If he is, soak the pelleted beet pulp to remove the molasses. It takes a long time, and the pellets will fall apart. The water should rinse clear when it’s free of molasses.

Alzheimer’s In Horses

Could my Cushing’s/insulin-resistant mare have Type 3 diabetes, which is linked to Alzheimer’s in people’ I heard that acetylcholine might help, and I’m willing to give it to my mare if that is the case.

Horse Journal Response

The term Type 3 diabetes has been coined to describe changes in the number of insulin receptors in the brains of Alzheimer’s patients. Insulin in the brain stimulates activity of the enzymes that produce acetylcholine, so a drop in receptors leads to decreased synthesis, which is a part of the neurotransmitter disturbances in Alzheimer’s. It has nothing to do with Cushing’s. The acetylcholine is a treatment for Alzheimer’s.

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