title: Severe hypertriglyceridaemia in horses and ponies with endocrine disorders.
abstract: BACKGROUND
  Severe hypertriglyceridaemia in horses and ponies with endocrine disorders has been reported anecdotally but has not been documented in the literature.
  
  
  OBJECTIVE
  To describe historical and clinicopathological findings as well as progression and outcome in horses and ponies with severe hypertriglyceridaemia (serum triglyceride concentration >5.65 mmol/l) secondary to an endocrine disorder that were otherwise apparently healthy.
  
  
  METHODS
  Cases from 6 participating institutions were identified and case details extracted from the medical records.
  
  
  RESULTS
  Case details of 3 horses and 4 ponies were available. Presenting complaints included weight loss despite good appetite in 4 animals, while in 3 hypertriglyceridaemia was identified incidentally. All animals were bright and alert and showed a normal or increased appetite. Serum triglyceride concentrations ranged from 10.5 to 60.3 mmol/l. Other abnormalities included hyperglycaemia in 6 animals, suspected insulin resistance and mild to severe increases in hepatic enzyme activities. In 2 animals, moderate hepatic lipidosis was confirmed histologically. Three horses and 3 ponies were diagnosed with pituitary pars intermedia dysfunction based on clinical signs and basal adrenocorticotropic hormone (ACTH) concentrations or dexamethasone suppression test results. In 5 of these, type 2 diabetes mellitus was also confirmed, while one pony suffered from type 2 diabetes mellitus without concurrent pituitary pars intermedia dysfunction. Laboratory abnormalities improved in 4 animals with treatment (pergolide and/or insulin), in one horse specific treatment was not attempted, and in 2 ponies treatment was impaired by the owner or only partly effective. In one of the latter cases, biochemical abnormalities persisted for 7 years without apparent ill effects.
  
  
  CONCLUSIONS
  Horses and ponies may develop severe hypertriglyceridaemia secondary to endocrine disorders that are associated with insulin resistance. Hypertriglyceridaemia can resolve with treatment of the endocrinopathy. Although biochemical evidence of hepatic compromise was present, clinical abnormalities were not noted in these animals.
authors.affiliation: Department of Veterinary Clinical Sciences, The Royal Veterinary College, North Mymms, UK.
authors.forename: B
authors.initials: B
authors.lastname: Dunkel
authors.forename: S A
authors.initials: SA
authors.lastname: Wilford
authors.forename: N J
authors.initials: NJ
authors.lastname: Parkinson
authors.forename: C
authors.initials: C
authors.lastname: Ward
authors.forename: P
authors.initials: P
authors.lastname: Smith
authors.forename: L
authors.initials: L
authors.lastname: Grahame
authors.forename: T
authors.initials: T
authors.lastname: Brazil
authors.forename: H C
authors.initials: HC
authors.lastname: Schott
mesh_terms: D000818:Animals; D004700:Endocrine System Diseases / Q000150:complications / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000097:blood* / Q000209:etiology; D006736:Horses; D015228:Hypertriglyceridemia / Q000209:etiology / Q000662:veterinary*; D008297:Male
keywords: diabetes mellitus; hepatic lipidosis; horse; hyperlipaemia; hypertriglyceridaemia; pituitary pars intermedia dysfunction