Roughage —
25 September 2025
Lolitrem in forage: a possible cause of ataxia in horses and ponies
Does your horse or pony suffer from coordination issues, balance problems (ataxia), or staggering? Poisoning by Lolitrem B may cause these symptoms. Recently, elevated concentrations of Lolitrem have been found in forage.
What is Lolitrem?
Lolitrem B is een gifstof dat geproduceerd wordt door de schimmel Neotyphodium Lolii. Deze schimmel leeft in symbiose met raaigras en beschermt de plant tegen insectenvraat. Bij stressomstandigheden, zoals droogte, gaat deze schimmel echter het giftige Lolitrem B produceren. Hierdoor kan ruwvoer van raaigras verhoogde gehalten Lolitrem B bevatten.
What are the symptoms?
A Lolitrem poisoning in horses or ponies can be recognized by one or more of the following symptoms:
- reduced appetite
- nervousness or jumpiness
- standing with legs spread wide
- trembling (muscle tremors)
- stiff gait
- unsteady stance, frequently seeking support
Endophyte-free forage without ryegrass
Poisoning cannot be identified from the outside appearance of silage or hay. It is therefore wise to ask the supplier for assurance that no endophytes (fungi) were used in the production of grass seed hay and that the hay does not originate from ryegrass.
What can you do?
When the source of poisoning (silage or grass seed hay) is removed, the symptoms usually disappear quite quickly. Always consult your veterinarian if you recognize one or more of these symptoms in your horse or pony.