09/06/2026
š¦ MYCOTOXINS ā ITāS NOT JUST A CORN PROBLEM
Weāve been talking about corn in horse diets, but that brings up a much bigger subject:
MYCOTOXINS.
And I donāt want anyone walking away thinking this is simply a ācorn problem.ā
It isnāt.
Mycotoxins are toxic compounds produced by certain molds. Depending on growing conditions, harvest, processing and storage, they can potentially show up in a variety of feeds horses consume.
Potential sources can include:
š½ Corn
š¾ Oats
š¾ Barley
š¾ Wheat and other cereal grains
š± Pasture grasses
š¾ Hay and forage
š„£ Feed ingredients and byproducts made from affected crops
š“ Finished feeds containing contaminated ingredients
MOLD ā MYCOTOXINS
This distinction is important.
Not every mold produces harmful mycotoxins.
And the opposite is important too:
You canāt assume feed is free of mycotoxins because you canāt see or smell mold.
Some contamination begins while the crop is still growing. Other problems develop or worsen around harvest and storage.
Heat, humidity, crop stress, insect damage, improper drying and moisture during storage can all influence the risk.
WHICH MYCOTOXINS MATTER TO HORSE OWNERS?
There are many, but several youāll hear discussed in animal feeds include:
ā ļø Fumonisins
ā ļø Aflatoxins
ā ļø DON (vomitoxin)
ā ļø Zearalenone
ā ļø T-2 and related trichothecenes
Horses are particularly sensitive to fumonisins. Significant exposure can cause equine leukoencephalomalacia (ELEM), a serious and potentially fatal neurologic disease.
WHAT DO MYCOTOXINS LOOK LIKE IN A HORSE?
Hereās where we need to be careful.
There isnāt one universal āmycotoxin symptom.ā
Depending on the toxin, concentration, amount consumed, duration of exposure and the individual horse, problems can be very different.
Possible concerns can include:
⢠Reduced appetite or feed refusal
⢠Poor body condition
⢠Digestive disturbances
⢠Reduced performance
⢠General unthriftiness
⢠Liver or kidney injury with certain toxins
⢠Immune-system effects
⢠Neurologic signs with severe fumonisin exposure
And many of those signs can have dozens of other causes.
Thatās why I donāt like diagnosing āmycotoxinsā simply because a horse doesnāt feel right.
š¬ļø WHAT ABOUT A COUGHING HORSE?
A constantly coughing horse absolutely makes me investigate its feed AND environment.
But coughing does not automatically mean mycotoxins.
Iām looking at:
š¾ Dusty or moldy hay
šØ Airborne mold spores
šļø Dusty bedding
š Poor barn ventilation
š“ Equine asthma/airway inflammation
š¦ Respiratory infection
šæ Environmental allergens
š„£ Feed quality and storage
Sometimes the mold itself and the dust/spores the horse is inhaling are a much more direct respiratory concern than a mycotoxin contained in the feed.
š”ļø WHERE DOES KOMBAT KLEER FIT?
When undesirable compounds in feed or the environment are a concern, Kombat Kleer can be considered as nutritional support.
But this is REALLY important:
A support product doesnāt make contaminated feed safe.
If I genuinely suspect a batch of hay or feed is contaminated, my first response isnāt:
āWhat can I add to the bucket?ā
Itās:
āShould this still BE in the bucket?ā
Remove questionable feed, investigate the source and consider laboratory testing when warranted.
MY DOāS & DONāTS
ā
DO buy hay and feed from sources you trust.
ā
DO store feed somewhere clean, dry and protected from moisture.
ā
DO inspect hay and grain regularly.
ā
DO pay attention when a horse suddenly refuses a feed it normally eats.
ā
DO consider laboratory testing when thereās a legitimate reason to suspect contamination.
ā
DO investigate chronic coughing separatelyāthe horse may be inhaling dust or mold even when mycotoxins arenāt the problem.
ā DONāT assume only corn can have mycotoxins.
ā DONāT assume ānatural,ā whole grain or expensive feed automatically means mycotoxin-free.
ā DONāT assume that because you canāt SEE mold, there canāt be a problem.
ā DONāT feed visibly spoiled or questionable feed and expect a supplement to make it okay.
ā DONāT diagnose every vague symptom as āmycotoxins.ā
š“ THE TAKEAWAY
Mycotoxins arenāt an ingredient. Theyāre a feed-quality problem.
They can potentially occur in grains, forage and other ingredients.
Know where your horseās food comes from.
Store it correctly.
Pay attention to changes in smell, texture, moisture and your horseās willingness to eat it.
And remember:
The best mycotoxin strategy starts before anything ever goes into the feed bucket.