Countermeasures for pasture-associated laminitis in ponies and horses

Laminitis occurs throughout the world in horses and ponies and has major welfare implications. It is obviously important to be able to recognize and treat the condition in its early stages so that pain and suffering are kept to a minimum. However, ideally it would be preferred to be able to recommend certain interventions/ countermeasures that avoid or prevent the condition from occurring in the first place. Because pasture-associated laminitis occurs with grass consumption, one obvious way to avoid the condition is to prevent access to pasture and to feed forage alternatives that are known to be low in rapidly fermentable material. For the majority of horses, total restriction is not always a viable or desired option for financial, welfare, and health reasons. It also may not be necessary for those animals that are not predisposed to laminitis. This review discusses the possible countermeasures that could be considered now and in the future in the following 7 key areas: 1) Identifying animals predisposed to the condition; 2) Limiting development of insulin resistance; 3) Avoiding high intakes of rapidly fermentable material; 4) Preventing/reducing the formation and absorption of the various ‘‘triggering factors’’; 5) Reducing/ preventing oxidative damage; 6) Preventing/reducing matrix metalloproteinase activity; and 7) Preventing changes in blood flow. It is unfortunate that little or no hard data exist at present on effective countermeasures, only mechanistic evidence for avoiding risk factors. However, there is much to gain, and research in this area is urgently required.