Thursday, March 08, 2012

Vitamin A Question

A reader asked about my article Making It Through the Tough TimesWould a Vitamin A source be needed, and if yes, which one would you suggest?

In the article I outlined the essential basics our horses need to maintain good health. 
Included were:
  • The best hay you can find and afford (grass or mixed)
  • The trace minerals copper and zinc
  • Iodized salt (to provide both salt and iodine)
  • Selenium if you're not in a high selenium area

plus flax and vitamin E when your horse does not have access to growing pasture.

Hay will retain good levels of vitamin A for several months.  In addition, horses store vitamin A in the liver - this is usually sufficient to carry them over the winter until new pasture or spring cuttings of hay are available.  

Once hay is more than six months old, especially in late winter to early spring, you may want to supplement some vitamin A.  In the Arizona regional mixes, vitamin A has been included at a minimum level (15,000 IU) to provide an "insurance" level. 

I like to evaluate the horse's coat condition in the spring to help me decide if I should begin adding some vitamin A until spring forage is available.  If the skin is "scurfy" - dry and flakey with an excess amount of "dandruff" even after a good grooming - I'll add some vitamin A and evaluate for improvement in ten days to two weeks.  Several other things can cause poor coat and skin condition including mineral imbalance, inadequate protein, parasites, illness or dehydration, or can interfere with vitamin A absorption or storage.  But in an otherwise healthy horse I'll expect to see improvement in skin and coat texture.

You can use either beta carotene or "preformed" vitamin A - both are available as human gel-caps from the drug store or from online sources such as  If using beta carotene, look for one that provides a minimum of 25,000 IU of vitamin A activity.  I have used beta carotene with good results but, as horses convert only a portion of the beta carotene to useable vitamin A,   preformed vitamin A will likely give faster results.

If your hay was a late season cutting, deep green and still looks, smells and feels fresh in late winter/early spring and your horse is shedding out to a soft shiny coat with no signs of skin dryness, you probably don't need to add vitamin A.  But if your hay was put up early last summer and your horse's skin and coat are dry and lifeless despite knowing he's getting the essentials, give a couple of weeks of vitamin A a try. 

To learn all the essential requirements your horse should have, consider starting with  Dr. Kellon's NRC Plus nutrition courses.  

Saturday, March 03, 2012

Immune Boosters

A question was posted the other day on a local equine group discussion forum:
I am hearing a lot about immune boosters for both people and animals.   Does anyone out there have any experience with them?  Any suggestions for brands and where to get?
Thank You,
Responses included recommendations for APF  from and Total Immune Health - a Chinese herbal mixture from FLOTH
Hi DiAnne ~

APF (Advanced Protection Formula) is a concentrated tincture of three ginsengs, which are in the group of "adaptogenic" herbs.  These herbs tend to "normalize" body systems - an example might be calming a hyperactive horse and improving alertness in an exceptionally laid back horse. 

This article from the APF site provides some interesting information but doesn't really explain why adaptogens work.

This Wikipedia article gives a little better idea.

Canadian ginseng powder will give similar results; good sources are 

If looking for immune support for a specific condition, you want to differentiate between an immune "stimulant" (something that boosts immune response, like adjuvants in vaccines do) and an immune "support" product (substances that allow the body to modulate the source/cause of inflammation).  You want to avoid immune "stimulants" if treating an autoimmune related inflammatory condition (for example Transfer Factor is an immune stimulant).  

Many immune "support" supplements act as anti-inflammatories through a variety of mechanisms - 

Spirulina acts on leukotriene receptors (similar to the human asthma medication Singulair) to reduce production of histamine

Duralactin (and other milk protein, whey protein or colostrum-based products) appears to block cytokines to inhibit neutrophil participation in the inflammatory response

Chondroitin has anti-inflammatory action not only on joints but on many other body systems at a cellular level (making it very useful for sterile urinary tract inflammation in cats along with skin "allergies" in horses).

Anti-oxidants play a strong role in supporting the immune system in horses - vitamin E, Omega-3 from flax, selenium, grape seed extract (, along with balanced minerals and vitamins.  

IMO, if you start out with quality feed and hay, (preferably mineral balanced), provide a good level of anti-oxidant support including flax and vitamin E for horses not on pasture, avoid excessive iron, and provide lots of exercise you generally won't need pricy "immune" products except for periods when your horse is exposed to extra stress. For travel, competition, new experiences, etc. I'd reach for the APF or ginseng.  For "allergic" (inflammatory) responses, I'd look to vitamin E, flax, Spirulina and chondroitin, and consider whey protein, colostrum or Duralactin as a next line of defense. I also feel it's important you have an idea of what results you expect from a nutrient (product, herb, etc.) before spending a lot on something.

A lot of people indicate they've had success with the FLOTH herbs - I feel they can be a bit pricey and not always useful if the basics haven't been covered first and I'm not well versed enough about TCM (traditional Chinese medicine) to comment on the specific herbs used in the formulas.  As with any herb, if they're potent enough to be effective, they're potent enough to have undesired side effects if used incorrectly.