Ask Horse Journal: 04/06

Vaccinations The Right Way
I am the only one at our barn, and my vet’s only client, that refuses to give my horse multiple vaccines in one vet visit.?? She finds me “inconvenient” but is willing to work with me.?? I have three questions:??

1.?? What is the desired time increment between vaccines’?? I was doing one per month, and she’d like to make it two per month.??

2.?? I’ve been pleased with the Merial West Nile vaccine due to your recommendations, so are there other manufacturers that you’d recommend for additional vaccines’?? I need to provide my horses with strangles intranasal, rhino/flu, rabies (only doing every other year), tetanus and encephalitis.??

3.??I have read that administering Thuja prior to vaccines can benefit horses that tend to be reactive.????Do you have any experience with this’

Your vet’s suggestion of every two weeks will probably work as well as every four. By two weeks post vaccination, antibody responses are usually well under way, indicating the immune system has recognized the vaccine and reacted.

As for vaccine choices, there is only one intranasal strangles choice, and one vaccine approved for rabies vaccination in horses.?? There’s no set answer regarding which vaccines to avoid, except to avoid vaccine brands that have caused a problem in the past since there’s a good chance the reactions could have as much to do with the adjuvants as to the disease antigens.

If your horse has tolerated a particular vaccine well in the past, even if a simple combo (e.g. encephalitis/tetanus), while that’s no guarantee you will never have a reaction, that is still the vaccine we would stick with.

Thuja is a homeopathic made from white cedar. Its use with vaccinations dates back to the crude smallpox vaccines, which were actually deliberate infections. Thuja is a remedy for skin eruptions/problems.?? In homeopathic terms, it is not indicated for vaccine reactions across the board, and there’s no solid evidence whatsoever that it helps prevent reactions.


Listerine On Rain Rot
I just finished reading my February issue and have a quick comment about rain rot. I rescued a big, old draft horse that had rain rot so badly, he was bleeding in some spots. The vet gave me antibiotics, but in addition to the everyday bathing, she recommended using Listerine as a fungicide. It was cheap and worked wonders.

Listerine is effective against a wide range of organisms, both bacteria and fungi. However, caution should be used as it may sting broken skin severely, and it is drying. Diluting it to make it less irritating may also make it ineffective. It also won’t work until the crusts are off so that the chemical can get at the organisms. Listerine’s base is 26.9% alcohol. The active ingredients are thymol, eucalyptol, methyl salicylate and menthol. Because of these ingredients, Listerine has??been used as an effective leg brace and sweat, too, but even on intact skin may cause some irritation.


After reading your article about feeding magnesium to insulin-resistant horses, I did not find the recommended amount to feed a 1,000-pound horse per day.??

Feeding insulin-resistant horses has come a long way since our first field??trial of magnesium.?? Five to 10 grams/day is a reasonable amount for a??1,000-lb. horse on most diets, but if you’re going to continue supplementation it should be based on knowing how much is already in the horse’s diet. Aim for twice as much calcium as magnesium in the total diet, including hay and grain. But remember that it’s also important to balance all of the minerals in the diet, not just the amount of magnesium.

Controlling insulin resistance (IR) takes more than just a magnesium supplement.??Strict control of sugar and starch intake is also essential. No grain. Even many of the low-carb feeds aren’t low enough for these horses.??Pasture grasses can have high sugar and/or starch levels, which change over the day and throughout the grazing season. There’s no 100% accurate way to predict the safety of a pasture, so letting an IR horse graze always comes with an element of risk of laminitis.

Hay should be the staple of the diet, but even some hays have too much sugar and starch. Some IR horses can tolerate up to a level of about 13% combined sugar and starch, but others will continue to have problems with weight gain, abnormal fat deposits and laminitis unless the level is brought down to less than 10%. If hay testing isn’t a feasible option because of frequent changes in hay, soaking the hay before feeding will leech out some of the sugar.??

The diet is rounded out with small amounts of no-molasses-added soaked beet pulp as a carrier for supplements and a “meal” substitute, and 3 to 4 oz. of ground stabilized flax will supply the horse with essential fatty acids in ratios that are the closest to a diet of grass.??

The final element, often overlooked, is exercise. Exercise has been proven, both in other species and specifically in the horse, to improve insulin resistance.


Lyme Disease
Three of my four horses were diagnosed with Lyme disease last May.?? These three were treated pretty aggressively with antibiotics for the entire summer.?? The fourth horse??tested negative and was vaccinated with the canine Lyme vaccine.??Last month we pulled blood to check the three positive horses’ blood titers.??There was no change in the levels, and they remain high.?? These horses have never shown classic signs of Lyme — joint pain, stiffness, behavior changes.?? Do you think putting them on a supplement to support their immune system would help’?? My theory is that maybe it would help clear the infection.??

High titers don’t necessarily mean active infection. With Lyme in particular, several human studies have found that titers can remain elevated for a very long time, and there is considerable argument about whether this means the person is still infected or not. That said, a study done at Cornell and published last year followed the titers of ponies experimentally infected with the Lyme organism and treated with either tetracycline, doxycycline or ceftiofur antibiotics. Titers declined initially in all three groups but started to rise again at the three-month mark in some of the doxy and ceftiofur-treated ponies.?? Postmortem tissue cultures showed no organisms in the negative-titer ponies, but persistent organisms in those that still had a titer. This would suggest your horses are still infected, but there’s also the possibility they were re-exposed (but not necessarily infected) last fall.

If they’re still infected, they need effective antibiotic therapy, which may involve intravenous tetracycline. Caution is advised with “immunostimulants.” Substances that actually stimulate the immune system do so by triggering a reaction themselves. This includes both herbal and injectable prescription products. However, these may well stimulate it in the wrong direction. Without knowing if there really is a weakness in the immune response, it’s impossible to intelligently pick the correct type of immunostimulant. Your safest course for immune system support is a mineral-balanced diet, including adequate selenium and vitamin E.


I have??been rereading issues from July and October 2005 in which mineral supplementation is discussed. ??The addition of a trace-mineral salt was not a consideration.

Trace-mineral supplement salts come in two basic varieties — livestock and equine-specific. Most livestock general trace-mineral supplements do not contain enough copper for horses because sheep and goats are sensitive to copper toxicity. The equine trace mineral salts are a better choice.

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