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

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 Manawatu 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.

Causes of mortality of kiwi (Apteryx spp.) in New Zealand: a retrospective analysis of post-mortem records, 2010-2020.

AIMS: To examine and assess causes of mortality of kiwi (Apteryx spp.) submitted to Massey University between 2010 and 2020 across the five recognised species according to location, age group and captivity status in New Zealand. METHODS: Post-mortem reports were obtained from the Massey University/Te Kunenga ki Purehuroa School of Veterinary Science/Wildbase Pathology Register. Inclusion criteria were all species of kiwi with a date of post-mortem examination between August 2010 and August 2020. Data from each report was exported, categorised and compared using Microsoft Excel. RESULTS: Of a total of 1,005 post-mortem reports, there were 766 North Island brown kiwi (NIBK; A. mantelli), 83 tokoeka (A. australis), 73 rowi (A. rowi), 49 great spotted kiwi (A. haastii), and 34 little spotted kiwi (A. owenii). This comprised 19 eggs/embryos, 125 neonatal, 473 juvenile, 153 subadult, and 235 adult kiwi. There were 615 kiwi from wild populations, 148 from sanctuary populations, 238 from captivity, and four from unspecified locations. The leading cause of death was trauma, affecting 322 (32.0 (95% CI = 29.2-35.0)%) kiwi including 289 (37.3 (95% CI = 26.0-31.7)%) NIBK. Nearly half of these died from predation by mustelids, with losses recorded from neonates to adults and clustered in the central to southern North Island. Predation by dogs was the second most common cause of death, killing 84 (8.4 (95% CI = 6.7-10.2)%) kiwi, of which 65.5% came from the northern districts of the North Island. Non-infectious disease killed 214 (21 (95% CI = 18.8-24.0)%) kiwi, and included developmental deformities, gastrointestinal foreign bodies and predator trap injuries. Infectious disease killed 181 (18.0 (95% CI = 15.7-20.5)%) kiwi and the proportion decreased with age, with common diagnoses including coccidiosis, bacterial septicaemia, avian malaria, and fungal respiratory disease. Starvation affected 42 (4.2 (95% CI = 3.0-5.6)%) kiwi, comprised of mainly neonatal or juvenile individuals from wild or sanctuary populations, with a higher percentage seen in tokoeka (11/83; 13.3%) compared to other species (min 0%, max 5.9%). The cause of death was undetermined in 246 (24.5 (95% CI = 21.8-27.3)%) cases, which was most often due to poor preservation of remains. This included 33/73 (46%) rowi and 32/83 (39%) tokoeka, and affected mainly birds from sanctuary and wild populations. CONCLUSIONS: This study enhances our understanding of causes of mortality in captive, wild and sanctuary populations of all kiwi species and age groups within contemporary New Zealand.

Histopathological Characterization of Cutaneous Delayed-type Hypersensitivity and Correlations with Intestinal Pathology and Systemic Immune Responses in Sheep with Paratuberculosis.

Cell-mediated immunity has been exploited historically in the diagnosis of mycobacterial diseases through elicitation of a delayed-type hypersensitivity (DTH) reaction following intradermal injection of an antigen. Here we describe the histopathological features of the cutaneous DTH reaction and its association with intestinal pathology and systemic immune responses in sheep with Mycobacterium avium subspecies paratuberculosis (MAP) infection. A mixed mononuclear cellular infiltrate dominated the DTH reaction and was present in perivascular and periadnexal patterns. Multiple multinucleate giant cells were present in the cellular infiltrate in one sheep while plasma cells were an obvious feature in six others. Sheep with paucibacillary intestinal lesions had the greatest degrees of cutaneous induration, more severe cellular infiltration in DTH lesions and high systemic interferon (IFN)-γ production. In contrast, sheep with multibacillary intestinal lesions, and particularly those with dissemination of MAP to extra-intestinal tissues, had minimal cutaneous induration, nil to mild cellular infiltration in DTH lesions and high serum anti-MAP antibody levels. Systemic IFN-γ production generally was augmented following skin sensitization. In general, the gross and histopathological features of the cutaneous DTH response matched the stage of paratuberculosis reflected by intestinal pathology and systemic measures of humoral and cellular immunity.