Desert Equine Balance: Immune System Support: the Basics

There are a lot of products out there which claim to support the immune system - some are beneficial and some are just unsubstantiated hype - and most are expensive. So what should you do if you feel your horse needs some help to stave off winter stress or to make it less likely he'll catch what the horse down the road has?

Immune system support starts with some basics which should be included in every horse's diet. Before considering any expensive "specialty" products, make sure your horse's diet includes:

Clean water at a drinkable temperature. If you use automatic waterers, buckets or tanks should also be available. Every winter I hear from someone who's horse went without water for a day or longer because the auto waters froze up.
Salt is often overlooked but is important to encourage adequate hydration. A 1000 lb horse should receive an ounce of salt (about 4 teaspoons/day) year round.

Inadequate sodium (from salt) can lead to dehydration at a "cellular" level which can impede or obstruct normal cellular metabolism.
Plain white table salt is best. "Designer" salts make attractive door stops but may contain high levels of undesirable minerals.
If your supplement contains less that the minimum requirement for iodine (most only contain 2 mg) use iodized salt which contains about 1.7 mg iodine per ounce.

Adequate quality forage, preferably mainly grass hay, with additional provided as needed for colder temperatures. (See the Cold Weather Feeding Chart.)
If you feed mainly Bermuda hay and your horse doesn't seem to be looking/feeling his best, consider replacing some of the hay (up to half) with Timothy pellets. The added cost can pay off in improved condition and good health.

Avoid feeds with high levels of simple sugars and starch (which converts to glucose) as excessive glucose can support inflammation. The processing of "senior" feeds does help greatly with improving digestibility but some contain excessive starch. Look for high fiber feeds as these will be more apt to promote good gut health. Or give your senior horse a 50/50 combination of beet pulp and steamed or crimped oats plus hay and/or Timothy pellets, along with a quality supplement, for a nutritious senior diet.
Avoid feeds and supplements with "added" iron. Excess iron can help fuel inflammation and many forages already supply excessive levels of iron.
Look for a supplement which provides at least the minimum daily requirement for copper, zinc, iodine and selenium. For a 1000 lb horse these are:

Copper 90-125 mg
Zinc 360 mg
Iodine 3.2 mg
Selenium 1 mg

Vitamin E and Omega-3 are important antioxidants which decline rapidly when hay is cut and cured.

For best immune support, provide vitamin E at a rate of 1000 IU per 500 lbs of body weight (2,000 IU for a 1,000 lb horse). It doesn't matter if the vitamin E is synthetic or natural but it does need fat for absorption. Using human gel caps which also contain oil is best, otherwise add a small amount of oil at feeding time. For an inexpensive oil which also adds a small benefit from medium chained triglycerides, try Costco's Mediterranean Blend (canola, olive and grape seed oils).
The simplest and most cost effective source for Omega-3 is flax. Provide about 2 ounces/day of fresh ground flax seed (which can be pre-ground and stored in the refrigerator) or stabilized flax - HorseTech NutraFlax, Omega HorseShine or Triple Crown OmegaMAX.

Iodine and selenium are both important for adequate thyroid functioning.

If your supplement has inadequate iodine, use iodized salt or the original Source meal which has a guaranteed level of iodine. If using another kelp or seaweed product, check that the iodine level is guaranteed.
Most supplements include selenium at about 2 mg per serving (2 mg per day). If blood tests show low selenium levels, you may need to use a selenium yeast product such as Platinum Selenium Yeast at a higher than usual dosage to bring the level up. I feel using an oral selenium yeast algorithm is safer than selenium injectables.

The above list is what should be included in any horse's diet to ensure a healthy immune system. But older horses or those who are stressed or already ill can benefit from some additional nutrients:

Vitamin A - around 15,000 IU/day. Vitamin A losses in hay occur over time; if hay is over six months since cutting it should be supplemented. Many supplements provide this or you can use human gel caps.
Vitamin D - horses are able to synthesize their own vitamin D and it is also stored in the liver, usually in quantities sufficient to carry most horses through the winter. If supplementing, stay close to the minimum requirement (3,000 IU for a 1000 lb horse) as excessive D can be toxic. Again, if not provided in your supplement you can add human gel caps.
Glutamine - this is an amino acid which is being added more frequently to equine probiotics. It has been shown to be protective for the mucous membrane lining of the intestines which may help support the intestinal flora production of some immune modulators.

There has been more research lately showing the importance of the intestinal lining and intestinal flora in maintaining immunity.
Cost to provide glutamine is about $0.44 for 10 grams per day. See the links below.

B-vitamins - not likely deficient except in stressed horses or those with gut issues. May be included in supplements or can try a human "multi-B" tablet.

Adding yeast (Saccharomyces cerevisiae - Diamond V or Yea Sac) can help provide a substrate for intestinal flora, which synthesize the B vitamins, to thrive.

I'd certainly consider these basic and cost effective additions to my horse's diet before moving on to more exotic - and pricey - immune support therapies.

Warm regards,

Patti
in windy Vail AZ

Links:

Flax

HorseTech Nutra Flax http://www.horsetech.com/nutra-flax.html

Omega Fields HorseShine http://www.omegafields.com/equine-products/omega-horseshiner.html

Triple Crown OmegaMax http://www.triplecrownfeed.com/products/supplements/triple-crown-omega-max-omega-3-oils-horse-health/

Glutamine MyBestHorse http://www.mybesthorse.com/productsorderhere.html

and PureBulk http://purebulk.com/l-glutamine-powder.html#.Uq3-1ZH-nfM

Selenium Yeast

Platinum http://www.platinumperformance.com/equine-selenium-yeast/productinfo/eselp1

HorseTech http://www.horsetech.com/selen.html

Vitamin E and Omega-3 Information and links to sources