Diagnosis > Equine

As the risk of mycotoxicosis is very difficult to predict or evaluate, prevention strategies should be initiated when assessing even a low risk situation. These must primarily aim at minimising mycotoxin formation in the field and during storage.

Cleanliness is vital and all feed bins and utensils should be cleaned regularly and kept dry. Mouldy or out of date feeds should not be fed even though they may not necessarily contain mycotoxins.  Hay and chaff products must be properly harvested and dried. Feed should preferably be kept within the bag until just before use and once opened stored in a cool dry place free from extreme temperature fluctuations. Cleaning areas around the mangers is also important. Pasture seed mixes must be guaranteed endophyte-free and particular attention should be paid to pregnant mares, keeping them away from endophyte-infected forage. Grass pastures should be topped regularly to maintain pasture in a vegetative growing state and prevent the formation of flowers and seed heads thereby reducing the opportunity for airborne contamination. Mares in late pregnancy should not be bedded on cereal rye straw. Straw can be tested. Hay and pasture samples may be tested for ergovaline and lolitrem B, but a lab should be chosen that uses HPLC methodology as this is more accurate than TLC. Studs should monitor foaling using a foaling record, which keeps information such as placental weights. If the placenta weighs more than 11% of the foal’s birth weight, then this is significant. For TB broodmares the placental weight should be less than 6.5kg.

Most feed manufacturers regularly test the raw materials and finished feed and many now add mycotoxin binders to the finished feed.

Non-feed sources of mycotoxins

Housing of horses on straw, shavings and other types of bedding is very common, particularly for horses in hard work. In winter many more horses are housed during the colder months. If the bedding is contaminated with mycotoxins, then horses are at greater risk of mycotoxicoses. In a recent Australian study over 80% of straw samples tested positive for mycotoxins. Straw quality in particular should be considered a risk factor for horses such as racehorses in training that spend up to 23 hours per day in stables.

Bedding in stables should therefore be cleaned out thoroughly and it should be noted that deep litter bedding is much more likely to contain fungi and therefore mycotoxins.