Deaths due to suspected hypothermia in sheep and alpacas on a Manawatū farm in New Zealand in mid-summer

N Z Vet J. 2024 Jan;72(1):39-44. doi: 10.1080/00480169.2023.2251425. Epub 2023 Sep 14.

Abstract

Case history: In mid-summer (February), 42 of a flock of 68 ram hoggets (approximately 5 months of age) and two of a group of 14 alpacas on a farm in the Manawatū region of New Zealand were found recumbent or dead following a period of persistent rain, strong winds and relatively low temperatures. The hoggets and alpacas had been shorn 4 and 53 days previously, respectively, and were in adequate to good body condition with access to ad libitum pasture. Post-mortem and histological examinations were undertaken on four hoggets and two alpacas.

Clinical findings: Apart from hypothermic body temperatures from four recumbent hoggets, nothing of significance was identified on clinical or gross pathological examination. Histological changes of vacuolar hepatopathy, renal tubular degeneration and pulmonary congestion were present in all animals examined.

Diagnosis: Based on the history and clinical and pathological findings, hypothermia was highly probable to have been the cause of the deaths.

Clinical relevance: These cases emphasise the importance of shelter for recently shorn sheep and alpacas regardless of the season.

Keywords: Sheep; alpaca; climate; cold exposure; hypothermia; mortality.

MeSH terms

  • Animals
  • Camelids, New World*
  • Farms
  • Hypothermia* / veterinary
  • Male
  • New Zealand / epidemiology
  • Seasons
  • Sheep