Many commercial products do not list their ingredients. Some preparations contain additives or supplements and cannot be fairly
compared to other probiotic preparations.
"For critical evaluation of a product," according to Weese, "It is essential to know the species and strain of the organism(s),
the concentration, and whether colonization and efficacy studies have been performed."
Horse owners are being exposed to marketing that favors the use of probiotics for treatment of any number of conditions. Probiotics
are recommended for any horse under stress. Horses in any type of training or competition are certainly stressed. Horses being
trailered, bred or recovering from surgery or illnesses are also considered stressed.
Neonates and older horses are thought to be able to benefit from probiotics because these horses are generally felt to have
sub-optimal digestion. Horses currently on antibiotics and horses that have chronic illnesses are also candidates for probiotic
therapy. There is a non-specific immune stimulation that is found with the use of some probiotics. It may be this immune stimulation
that actually accounts for the action of probiotics and much research is currently under way attempting to uncover the link
between probiotics and the immune system.
Probiotics may be involved with the transport of antigens within the intestine and may lead to a treatment approach for some
types of food allergies. It has also been suggested that probiotics can cause closure of large molecular transport pores in
the intestinal lining. While the closure of these pores or openings may keep harmful environmental toxins, bacterial endotoxins
and antigens from being absorbed by the host animal, these pores are also responsible for the absorption of immunoglobulins
within the first 24 hours of a foal's life.
Because of this closure issue, it may not be advisable to use probiotics in foals under 24 hours old. Additional research
in this specific area is needed.
Many equine practitioners have been recommending the use of yogurt as an additive for sick or stressed horses for years. Yogurt
as a probiotic is not a new concept and harkens back to those ethnic groups that attribute longevity to the consumption of
fermented milk products. Yet there are some guidelines to follow here as well. Only certain strains of bacteria in yogurt
and only sufficient numbers of these bacteria will achieve the desired results. Weese writes, "common yogurt products contain
strains of L. delbrueckii and/or S. thermophilus which have no demonstrable probiotic effect." Despite all the practical clinical
experience that many veterinarians and horse owners may have with yogurt seeming to be helpful, the actual research "has been
disappointing", according to Weese.
Even though veterinary researchers are yet unable to recommend specific probiotics and have not uncovered an exact reason
for some of the beneficial results that have been noted with probiotic use, there are valid reasons to continue to try these
products when indicated.
Be careful to determine which strains of bacteria are being fed and in what amounts. Use quality products and evaluate their
efficacy as you would any other therapeutic drug.
"It is logical to assume that certain probiotics will be effective in the treatment or prevention of certain conditions,"
writes Weese. "Which probiotics and which conditions," he cautions, "have yet to be determined."
Yet, as any 100-year-old man from the Soviet Union will tell you, you are what you eat.