title: A prospective study of basal insulin concentrations in dogs with congenital portosystemic shunts.
abstract: OBJECTIVE
  Hypoglycaemia is a common cause of morbidity in dogs with congenital portosystemic shunts but the aetiology is unknown. The hypothesis of this study was that dogs with congenital portosystemic shunts would have significantly higher insulin concentrations than dogs without congenital portosystemic shunts. The main objective of the study was to compare peripheral glucose and insulin concentrations between dogs with congenital portosystemic shunts and dogs without congenital portosystemic shunts.
  
  
  METHODS
  Peripheral serum insulin and plasma glucose concentrations were measured in dogs with congenital portosystemic shunts and without congenital portosystemic shunts and compared both between groups as well as to reference intervals derived from healthy dogs.
  
  
  RESULTS
  Congenital portosystemic shunts were diagnosed in 41 dogs. Forty-eight dogs hospitalised with other conditions acted as controls. Serum insulin concentrations were mildly elevated (Ä40 μU/mL) in seven dogs and were markedly elevated in two dogs with congenital portosystemic shunts, yet mild hypoglycaemia (3·3 mmol/L) was detected in only one of these dogs. Four dogs with congenital portosystemic shunts showed fasting hypoglycaemia, yet insulin concentrations were within or below the reference interval in three. There was no difference between the median insulin concentration of dogs with congenital portosystemic shunts and without congenital portosystemic shunts.
  
  
  CONCLUSIONS
  Hyperinsulinaemia is infrequently observed in dogs with congenital portosystemic shunts. The aetiology of hypoglycaemia in dogs with congenital portosystemic shunts merits further investigation.
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES.
authors.forename: A J
authors.initials: AJ
authors.lastname: Collings
authors.forename: A G
authors.initials: AG
authors.lastname: Gow
authors.forename: A
authors.initials: A
authors.lastname: Marques
authors.forename: D
authors.initials: D
authors.lastname: Yool
authors.forename: R
authors.initials: R
authors.lastname: Furneaux
authors.forename: R
authors.initials: R
authors.lastname: Mellanby
authors.forename: P J
authors.initials: PJ
authors.lastname: Watson
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D016022:Case-Control Studies; D004283:Dog Diseases / Q000097:blood* / Q000151:congenital; D004285:Dogs; D005260:Female; D007003:Hypoglycemia / Q000097:blood / Q000209:etiology / Q000662:veterinary*; D007328:Insulin / Q000097:blood*; D008297:Male; D011168:Portal System / Q000002:abnormalities*; D011446:Prospective Studies
chemical_list: D001786:Blood Glucose; D007328:Insulin