Mycotoxins and your horse

march 9, 2005
by Robyn Mauger
The Equi-Guard Story ...

Horses are often overlooked as the victims of mycotoxin problems, however they have a long and deadly history. For instance in 1934 more than 5000 horses died in the Midwest of the United States because of mouldy corn disease due to fumonisins Bı. The respective disease Equine leucoencephalomalacia (ELEM) is recognised since 1891. During WWII thousands of Russian horses died from eating mouldy hay. The cause was later found to be a tricothecene mycotoxin produced by a stachybotrys-type mould. More recently prominent equine nutritionists such as Dr Kyle Newman of Venture Laboratories and Dr Bill Vandergrift of EquiVision have come to suspect that the Kentucky foal death mystery may be attributable to mycotoxins. Chiefly suspected are the mycotoxins zearalenone and endophyte that are commonly found in rye grass.

A mycotoxin is the secondary metabolic product of moulds mainly belonging to the Fusarium, Aspergillus and Alternaria species. There are about 300 or so that are known to be potentially harmful to both humans and animals. Mycotoxins' structural, biological, chemical and toxicological make-up is extremely diverse, therefore their toxicity is variable depending on the intake level, duration of exposure, sex, age, breed, physiological status and nutritional standing of the animal.

Most horses are exposed to mycotoxins in the pasture they graze or the grains and hays that are offered to them. Mould growth and subsequent toxin production is generally influenced by a variety of plant and environmental factors whether at time of harvest (including eating) or in storage. Stress factors such as drought, poor fertilisation, high crop densities, weed competition, insect or mechanical damage can also weaken the plant's natural defences and make it susceptible to mycotoxin producing fungi which can the affect the horse feeding on it.

A horse with mycotoxin exposure will have clinical symptoms that are often not obvious or unique. Behavioural problems are the most obvious and include spooking, bucking, rearing, girthiness, lethargy, poor performance and aggression to name a few. These symptoms are the tip of the iceberg though, a large acute dose of some mycotoxins can kill a horse but the biggest problem is chronic sub-lethal or low doses. These can cause organ damage to the liver and kidneys, suppress the immune system and ultimately lead to secondary bacterial infections and general unthriftiness. This is often expressed in digestive disorders such as diarrhoea, feed refusal, colic, weight loss and dermatitis. Other types of mycotoxins can cause reproductive problems such as atrophy of ovaries and testicles, infertility, and abortion.

Diagnosis is not easy but there are common factors. Drug and antibiotic treatment have little or no effect on the disease. Outbreaks are often seasonal and usually associated with specific foods or foodstuffs. The most cost-effective way of diagnosing your problem is to remove your horse from the source of contamination or to administer a polymeric glucomannon mycotoxin adsorbent. This product binds the mycotoxin to itself in the gut and allows it to be passed out harmlessly in the manure. This compound is the main ingredient in Equi-Guard produced by Nutritech International and available from feed merchants, saddlers and vets throughout New Zealand. Equi-Guard is developed from modified fractions of the yeast cell wall. It is non-swab and can't be overdosed. It is available in a powder or pellet form for convenience of feeding. Most owners will notice a subsidence of symptoms within 5-10 days of administration.

Nutritech has looked at the mycotoxin problem holistically and also developed an herb-based detoxification called Equi-Pur to help cleanse the hepatic and renal systems. Used in conjunction with Equi-Guard the recommended treatment period is 21 days and can be administered in the feed or by syringe. It is recommended that it be used at least once a year if Equi-Guard is not being used as a year round preventative.

A useful tool in ongoing mycotoxin management is just being aware of what's happening in the pasture at different times of the year e.g. change of season, drought etc. At these times it may be strategic to administer higher doses of Equi-Guard and aim the annual flush to coincide with peak periods.

Article courtesy:

For further information please contact your local retailer or the
Nutritech South Island Horse Products Sales Specialist, Robyn Mauger
on 0274 464 118 or North Island Specialist Bay Barlow on 0274 735 688 or Nutritech on 0800 736 339.">Email Robyn