Grass sickness is a dangerous disease of horses in which the nervous supply to digestive tract is progressively paralysed.
It can happen in any horses but most commonly is seen in horses between 3-7 years of age. It occurs when horses are at grass in spring and summer and in horses turned out in the spring after winter stabling seem to be most at risk. It seems to be more common during fine sunny spells and certain fields seem to produce more cases.
The cause of grass sickness is unknown. It may be related to a neurotoxin of some kind found in plants. The diseased does not affect other species of animal.
Signs do vary a lot but can include the following: Trembling muscles, sweating and fast heart beat, difficult in swallowing, drooling, food passing through the nostrils, few gut sounds, colic
There is no cure of grass sickness and horses very rarely get better or recover. Sudden cases can die in a few days, less severe cases may live for a few weeks and chronic cases may survive for weeks or months.
Fields on which grass sickness has occurred should not be grazed by horses especially during the spring and early summer. Hay cut from these fields should not be given to horses.
Liver tonic supplements and immune support formulas can be useful to help enhance the overall health of horses at risk from grass sickness.