Current concepts of hyperlipaemia in horses and ponies
Jeffcott, L.B.; Field, J.R.
Veterinary Record 116(17): 461-466
1985
ISSN/ISBN: 0042-4900 PMID: 3890349 Document Number: 243514
Hyperlipaemia is an important condition in ponies, not only because of the seriousness of the clinical signs and biochemical changes involved, but because of the distress to owners and breeders. Hyperlipaemia occurs most commonly in fat ponies in late pregnancy and is rarely seen in larger horses. The syndrome has similarities with conditions in other species but the definitive aetiologies are not yet known. The condition in ponies is related to stress. The biochemical mechanisms involved are considered and a hypothesis is put forward. This hypothesis is tested by presenting the results of a preliminary study to evaluate glucose and lipid metabolism in horses and ponies. It appears that the pony is very insensitive to insulin compared to larger horses; thus triglycerides are more readily mobilized and the animal is, therefore, susceptible to hyperlipaemia in a situation of negative energy balance. The effect of stress is to increase cortisol levels which exacerbates the insulin insensitivity and creates a vicious circle. The importance of an innate insulin insensitivity may also be important in the pathogenesis of such conditions as laminitis.