10/12/2024
Thankfully we don’t see Grass Sickness commonly but when we do it is a devastating experience for everyone. We see a huge amount of colic in our out of hours work and it is always in the back of our mind, especially after specific weather conditions, that there is a small chance that Equine Grass Sickness may be the underlying cause. We can usually rule this concern out very quickly but for those cases where we can’t it is great to know that the disease is becoming better understood as a result of this recent research. Thanks to Western Counties Equine Hospital for sharing the report!
Equine Grass Sickness (EGS) breakthrough‼️
The recent discovery linking EGS to a neurotoxic enzyme, similar to toxins found in snake venoms, represents a significant breakthrough in understanding and potentially treating this devastating condition.
The Disease: 🦠
Equine grass sickness is a fatal condition affecting horses that graze on pasture, especially during cold and dry weather conditions. Horses suffering from EGS experience intestinal paralysis, colic, muscle weakness, tremors, and inability to swallow, often leading to death in about 1% of cases on high-risk premises.
Identification of the Neurotoxin: 📚
The research team, led by experts from the Royal (Dick) School of Veterinary Studies’ Equine Hospital, discovered that phospholipase A2, a type of neurotoxic enzyme, is likely the cause of the disease. This enzyme damages the neuromuscular junctions—the vital sites where nerve signals communicate with muscles—leading to paralysis, particularly of the gastrointestinal tract. This damage is linked to the clinical signs of the disease, such as colic and muscle wasting.
Microbial Origin: 🧫
The enzyme is thought to be produced by a microbe (likely a bacterium or fungus) that grows on pasture during cold and dry periods, which precede outbreaks of EGS.
Similarities with Snake Venoms: 🐍
The neurotoxin responsible for equine grass sickness has been shown to have a similar action to toxins found in the venom of many poisonous snakes. While venomous snakes do not cause EGS, some therapeutic treatments currently being developed for human nerve regeneration after snake bites may offer promising treatments for horses suffering from the disease.
Therapeutic and Diagnostic Potential: 🔬
The breakthrough offers hope for novel diagnostic tests and treatments for EGS. Research into the microbial sources of the neurotoxin is ongoing, and the development of treatments based on snake venom therapies is an exciting possibility.
