title: Histopathological examination of chronic laminitis in Kaimanawa feral horses of New Zealand.
abstract: OBJECTIVE
  To investigate the prevalence, histopathological and histomorphometric presentation of chronic laminitis in a population of Kaimanawa feral horses.
  
  
  METHODS
  Following the capture and euthanasia of feral horses from the Kaimanawa Ranges of New Zealand, the left forefoot of 28 stallions and 28 mares aged between 6 and 12 years were removed and processed for histology. Sections of lamellar samples from each horse were examined using light microscopy. The presence of laminitis was assessed and the histopathological lesions were described. Horses were grouped by histological diagnosis into laminitic and non-laminitic groups and histomorphometric analysis was conducted and compared between groups. The parameters examined were total length of primary epidermal lamellae (PEL), keratinised length of PEL, and the length of secondary epidermal lamellae (SEL) at the abaxial end and axial end of each PEL.
  
  
  RESULTS
  Of the horses examined, 25 (45%) were diagnosed with chronic laminitis. The most prevalent histopathological features were the presence of excessive cap horn, and multi-branched and attenuated SEL. Histomorphometric assessment of the lamellar architecture revealed no difference in morphometric measurements between the normal and laminitic groups for any parameter measured (p>0.05).
  
  
  CONCLUSIONS
  The current study found a high prevalence of laminitis in feral Kaimanawa horses. The reason for this in the Kaimanawa population is not known. Histomorphometric analysis may not be a good indicator of chronic laminitis in feral horses.
  
  
  CONCLUSIONS
  It is an important finding that the feral horse lifestyle in the environment of the Kaimanawa Ranges in New Zealand offers no protection against foot disease. The finding suggests that horses are vulnerable to laminitis whether in domestic care or in a feral habitat.
authors.affiliation: School of Veterinary Science, The University of Queensland , Gatton Campus , Australia. b.hampson1@uq.edu.au
authors.forename: B A
authors.initials: BA
authors.lastname: Hampson
authors.forename: M A
authors.initials: MA
authors.lastname: de Laat
authors.forename: C
authors.initials: C
authors.lastname: Beausac
authors.forename: T
authors.initials: T
authors.lastname: Rovel
authors.forename: C C
authors.initials: CC
authors.lastname: Pollitt
mesh_terms: D000818:Animals; D002908:Chronic Disease; D005260:Female; D005534:Foot Diseases / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D006724:Hoof and Claw / Q000473:pathology*; D006734:Horse Diseases; D006736:Horses; D007249:Inflammation / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D015995:Prevalence