What are mycotoxins?
Mycotoxins are toxins produced by moulds and fungi that can be found on fresh pasture grasses and hay, or even on commercial feed items that have been improperly stored. Virtually any feed item can potentially be infected by mycotoxins. It is possible for some feeds to contain multiple species of fungal toxins that may interact; the overall toxicity could then increase to a greater extent than with individual separate mycotoxins.
Is there any way to protect horses from mycotoxins?
Ensuring that all feeds are completely free of mycotoxins is very difficult. the harmful effects of mycotoxins may be reduced when toxin-binders are added to each feed. The toxin-binders work by attaching to the mycotoxins in the horse's gut so they cannot be absorbed; they are then harmlessly excreted. If your horses are on pasture/feed, weeds or clover affected by mycotoxins from moulds, they may be suffering and exhibiting all sorts of symptoms which can include:
- Scabby white noses
- Nasty behaviour
- Spooky behaviour
- Spaced out
- Dull coarse coat
- Failure to thrive
- Wasted topline, showing ribs but big grass belly
- Staggers/string halt
- Head flicking
- Unexplained cough/choke
- Digestive issue/colic
- Persistent greasy heel/rain scald
- Reproductive issues
Fungal mycotoxins are thought to be the cause of some cases of photosensitisation in horses.
The photodynamic pigments present within the fungal mycotoxin are ingested by the horse from pasture grasses or contaminated hay or feed. The pigments are absorbed through the gut wall, enter the bloodstream and circulate to the skin where they are exposed to UV light in areas of thin, non-pigmented skin such as muzzle and pasterns. The pigments react to the UV light by fluorescing which causes oxidative damage to the cells of the skin.
The resulting sores are painful, often being mistaken for sunburn. Greasy heel and mud fever may also be caused by photosensitisation.