Aims: To describe the morphology and prevalence of teat and udder pathology of New Zealand dairy ewes. Methods: A repeated cross-sectional study was conducted on 20 commercial New Zealand dairy sheep farms over the 2022-2023 season. Approximately 15 randomly selected ewes were examined on each farm in early, mid, and late lactation. Four udder morphology measures were scored on a 5-point scale: depth (1 = pendulous, 5 = compact udder), suspension (ratio of width at abdominal attachment to height, 1 = low, 5 = high), gland separation (1 = zero, 5 = maximum separation), and teat placement (1 = distally located, vertically oriented, 5 = laterally located, horizontally oriented teats). Teat length and width were measured, and the presence of supernumerary teats, asymmetry, visible teat/udder inflammation, and lesions were recorded. Teats and glands were palpated for consistency, gland-nodules, teat canal thickening, and patency, and teat ends scored for hyperkeratosis. Teat and gland-level pathological variables were converted to ewe-level scores. The presence of involuted, non- or minimally lactating glands was recorded. Data were analysed using descriptive statistics. Results: Across the three visits, 893 observations were made on 882 unique ewes. Mean teat length and width were 27.5 (95% CI = 27.2-27.7) and 15.8 (95% CI = 15.7-15.9) mm. Udder depth, separation, suspension, and teat placement had modal scores of 4, 3, 3, and 3 respectively, and varied across visits and age groups. Asymmetrical udder prevalence was 39% (95% CI = 35.5-42%) overall and increased with age (27% for 1-year-olds, 38% for two-year-olds, 43% for mixed age ewes). Supernumerary teats were observed in 15% (95% CI = 13-17.9%) of ewes. There was between-farm variation in all udder morphology variables. Ewe-level prevalences of teat end hyperkeratosis (any degree of severity), gland/teat inflammation, lesions, palpable defects, and involuted glands were all < 6%. Conclusions: Morphological observations resembled those from overseas dairy sheep. Teat dimensions, udder depth, separation, suspension, teat placement, and presence of supernumerary teats varied between farms. Udder depth, separation, and suspension scores decreased with age, while teat placement score and the prevalence of asymmetry increased with age. Teat and udder pathology were rare. Clinical relevance: This is the first systematic study of teat and udder morphology and pathology in New Zealand dairy ewes. The data will be useful for farmers and industry partners, providing a comparison with their own flocks, identifying areas for improvement, and informing and contrasting with future studies.

The West Coast region of the South Island of New Zealand is recognised as having a high prevalence of liver fluke infection, however, few studies have tested this assumption. This study aimed to estimate the seroprevalence and spatial distribution of liver fluke infection in most West Coast and some Canterbury dairy herds using bulk milk ELISA. Herds were bulk milk sampled on three occasions, twice, a week apart in March 2017 (n = 430 and n = 99) and once in October 2017 (n = 412). The concentration of liver fluke antibodies was estimated using the IDEXX Fasciolosis Verification ELISA (IDEXX Europe BV, Hoofdorp, The Netherlands) on these bulk milk samples. Herds were categorised according to the test instructions, with "medium" (>= 20 % cows infected) or "strong" (>= 50 % cows infected) results designated as production limiting. All herds were also sent a short questionnaire about awareness of liver fluke and treatment in their herds. The agreement between the IDEXX results for 99 herds sampled twice in March 2017, and between the IDEXX results for March and October for all herds was assessed with a Kappa test. There was a substantial agreement between the two March tests, kappa = 0.7 (95 % CI 0.58-0.82) and moderate agreement between the March and October samples kappa = 0.41 (95 % CI 0.34-0.48). The results of the questionnaire were linked to the IDEXX results, and the distribution of herds categorised by their IDEXX result plotted. At the March and October samplings 0/35 (0 %) and 0/27 (0 %) Canterbury herds, 248/395 (63 %) and 193/385 (50 %) of West Coast herds had a production limiting seroprevalence of liver fluke infection. Mapping showed that West Coast herds with a production limiting infection were clustered in coastal areas, whereas those without, were clustered in inland valleys. The odds of a coastal West Coast dairy herd having a production limiting seroprevalence of liver fluke were 10.7 (95 % CI, 6.6-17.3) times that of an inland herd in March and 8.6 (95 % CI, 5.4-13.8) times in October. There was no effect on IDEXX ELISA SP% (p = 0.92) of herds which were treated for liver fluke at dry off soon after the March test compared to their SP% in the following October test, soon after calving. The results show that liver fluke infection is a potentially serious problem for West Coast dairy herds especially for those on coastal river plains prone to flooding.

Aim: To assess whether the fluoride concentration in the humeri of first-lactation, 2-year-old dairy cows with a spontaneous humeral fracture is significantly different from that of first-lactation, 2-year-old dairy cows without a humeral fracture. Methods: Two studies were conducted, the first with nine bone samples from 2-year-old, first-calving dairy cows with a humeral fracture (all from the Waikato region) age-matched with seven control bone samples from the Waikato, Bay of Plenty and Manawat & umacr;-Whanganui regions. The second study used 26 bone samples from 2-year-old, first-lactation dairy cows with a humeral fracture (from the Otago, Canterbury, Southland, West Coast, Waikato and Manawat & umacr;-Whanganui regions) age-matched with 14 control bone samples (all from the Manawat & umacr;-Whanganui region or unknown). Control bone samples were from first-lactation, 2-year-old dairy cows that did not have humeral fractures. Bone fluoride concentration was quantified for all samples. Results: The median fluoride concentration of humeri from first-lactation, 2-year-old dairy cows with a humeral fracture was significantly higher than humeri from unaffected control cows in both studies. In Study 1, the median bone fluoride concentration was 599 (IQR 562.7-763.5) mg/kg from case cows and 296.6 (IQR: 191.2-391.7) mg/kg from control cows (p < 0.001), and in Study 2 the median bone fluoride concentration from case and control cows was 415 (IQR: 312.5-515) mg/kg and 290 (IQR: 262.5-410) mg/kg (p = 0.04) respectively. Conclusions and clinical relevance: Although there are limitations to this study due to the unbalanced regional distribution of cases and controls, the results indicate that sub-clinical fluoride toxicosis may be linked to spontaneous humeral fractures in first-lactation dairy cows in New Zealand. Further research is required to determine if bone fluoride concentrations play a role in the pathogenesis of these fractures.

In many regions of New Zealand liver fluke is endemic, infecting most grazing ruminants, including cattle, sheep, and deer. Restricting the economic losses and welfare costs associated with liver fluke relies on accurately identifying those animals with a production limiting infection. This has proven a difficult goal and although several antemortem quantitative tests are available, including faecal egg counts (FEC), serum ELISA and coproantigen ELISA, none can be considered a gold standard test of liver fluke infection. The accepted gold standard test for fascioliasis is the total fluke count, which is both laborious and can only be completed at post-mortem. This study aimed to compare the performance of four liver fluke diagnostic tests, against the results of a gold standard total fluke count test. Two groups of cattle were selected, 29 culled mixed age beef cows (MAC) and ten 30-month-old steers. The cattle were blood sampled and faecal sampled prior to slaughter and their whole livers recovered post slaughter at the abattoir. Liveweight was also recorded at slaughter. After collection, each liver was weighed, scored for gross pathology, then serum, faeces and livers were frozen at -20 degrees C for later analysis. Faecal egg counts and F. hepatica copro-antigen ELISA tests were completed on the faecal samples and total fluke counts were completed on the livers. Fasciola hepatica antibody concentration in serum samples were quantified using a commercial ELISA test. Poisson regression models were built to model the association between each diagnostic test and the total fluke count, and a linear regression model was built to examine the relationship between each diagnostic test and live weight at slaughter. The median fluke count was significantly higher in MAC than steers (p = 0.01), and F. hepatica eggs were present in 100% steers and 66% MAC. There was a significant effect of copro-antigen ELISA value on total fluke count (p < 0.0001), with a coproantigen ELISA value = 20.1 predicting 10 flukes and a value = 44.8 predicting 30 flukes. There was also a significant effect of FEC on total fluke count (p = 0.002) but the R-squared value for this model was lower. There was no association between liver fibrosis score or antibody ELISA test and total fluke count (p = 0.95, p = 0.73, respectively). There was a significant effect of total fluke count (p = 0.03) on liveweight at slaughter, with liveweight falling 20.4 kg for each unit increase in loge (total fluke count). There was no effect of FEC (p = 0.11), antibody ELISA (p = 0.55) or copro-antigen ELISA value (p = 0.16) on liveweight at slaughter. Taken together, these results show that the coproantigen ELISA test is the better test for estimating the true liver fluke burden and that the number of flukes in the liver has a negative effect on cattle live weights at slaughter.

Aims: To use a farm-based survey to identify characteristics of the New Zealand dairy system associated with the risk of spontaneous humeral fracture in dairy heifers.Methods: A questionnaire was designed and made available in print and online to collect information from dairy farmers and/or veterinarians, across New Zealand, about the management and nutrition of cows from birth to first lactation. Data were collected from July 2019 to March 2020 from farms that either had recorded (case farms) or not recorded (control farms) cases of humeral fractures in dairy heifers.Results: A total of 68 completed questionnaires were returned, with 35 responses from case farms and 33 responses from control farms. Twenty-six responses (38%) were from the South Island (13 case farms and 13 control farms) and 38 responses (56%) were from the North Island (20 case farms and 18 control farms). For four questionnaires (6%) farm location was not given. Adjusting for the effect of age when calves accessed pasture, case farms had increased odds of having Holstein-Friesian Jersey crossbreed cows as the predominant breed (OR = 9.7; 95% CI = 3.1-36.0; p < 0.001). Adjusting for the effect of breed, allowing calves access to pasture a week later decreased the odds of being a case farm (OR = 0.68; 95% CI = 0.47-0.90; p = 0.006).Conclusions: Cows being Holstein-Friesian Jersey crossbreed was identified as a possible risk factor associated with spontaneous humeral fracture in dairy heifers in New Zealand. Given the small sample size, the likely multifactorial aetiology for humeral fractures, and the non-randomised survey, this risk factor, and the possible association between age at turn out and herd production with humeral fractures, all require further investigation.

CASE HISTORY:In spring 2021, on a seasonally calving, pastorally based, Taranaki dairy farm, 12 first-calving heifers (≤ 30 days post-calving) developed similar dry, red to black, crusting lesions on the medial aspect of the teat udder junction extending down the medial teat. Some cows had multiple teats affected. Treatment was initially unrewarding and did not slow the progression of the disease. Overall, 8/12 cows recovered, and 4/12 cows were culled, with three of the cows culled after a teat sloughed and the fourth after surgical amputation of a teat. Outbreaks of the same condition, on the same farm but affecting fewer animals, occurred in spring 2022 (n = 6) and spring 2023 (n = 3). CLINICAL FINDINGS:An initial scab-like or crusting lesion progressed to resemble a thick eschar consisting of very dry and hard dead tissue. The unaffected areas of the teat felt normal but immediately under the dead tissue, there was a warm, firmer area consistent with an inflammatory reaction. Removing the scab led to profuse bleeding, with no visible bed of granulation underneath the scab. There was no leaking of milk in those cows that lost a teat, and no smell to the lesions themselves. Serology and virology ruled out the involvement of bovine alphaherpesvirus (BoHV-2) bovine gammaherpesvirus (BoHV-4), orthopoxviruses (cowpox) and parapoxviruses (pseudocowpox). Histopathology of an affected and surgically amputated teat showed multifocal erosion and ulceration of the epidermis, covered by a thick serocellular crust. In areas of ulceration, there were numerous neutrophils, and the dermis was expanded by granulation tissue with variable numbers of neutrophils, eosinophils, and lymphocytes around small blood vessels. DIAGNOSIS:Based on the similarity of the history, presentation, and histopathological changes to those described for a novel disease reported in the UK, a diagnosis of ischaemic teat necrosis (ITN) was made. CLINICAL RELEVANCE:If ITN is an emerging condition in New Zealand and becomes as prevalent as it has in the UK, clinicians will be confronted with a significant new welfare problem in dairy cows. Anecdotally, there have been reports of other ITN outbreaks in New Zealand, and the Ministry for Primary Industries would be interested in collating reports from other New Zealand veterinarians.

Flystrike remains an important animal health issue on New Zealand sheep farms. To date no useful predictive tool to assist farmers to develop control options has been available. The aim of this study was to use National Institute of Water and Atmospheric Research (NIWA) virtual climate station data in New Zealand to develop a weather-based model to accurately predict the presence of Lucilia spp. on sheep farms throughout New Zealand. Three LuciTrap (R) baited fly traps were positioned on each of eight sheep farms throughout New Zealand (5 in the North Island and 3 in the South Island). The traps were put out for both the 2018 - 2019 and 2019 - 2020 seasons. They were emptied each week and the flies morphologically identified; with the counts of Lucilia cuprina and L. sericata combined as Lucilia spp. The count data for Lucilia spp. for each week of trapping was transformed into a binary outcome and a generalised linear mixed effects models fitted to the data, with farm as a random effect. The dependent variable was Lucilia spp. flies caught, yes or no, and the independent variables were mean weekly climate variables from the nearest NIWA virtual climate station to that farm. The model was trained on the 2018 - 2019 catch data and tested on the 2019 - 2020 catch data. A cut point was identified which maximised the model ' s ability to correctly predict whether Lucilia spp. were present or not for the 2019 - 2020 catch data, and the sensitivity, specificity, accuracy, and area under the curve (AUC) of the model calculated. The final model included just 3 significant variables, mean weekly 10 cm soil temperature, mean weekly soil moisture index, and mean weekly wind speed at 10 m. Mean weekly 10 cm soil temperature accounted for 64.7% of the variance explained by the model, mean weekly soil moisture index 34.7% and mean weekly wind speed at 10 m only 0.6%. The results showed that the predictive model had a sensitivity of 0.93 (95% CI = 0.80 - 0.98) and a specificity of 0.75 (95% CI = 0.62 - 0.85), using a cut point for the probability of Lucilia spp. being present on farm = 0.383. This model provides New Zealand farmers with a tool which will allow them to know when Lucilia spp. flies will likely be present and thus more accurately plan their interventions to prevent flystrike.

Aims: To determine whether evidence for infection with Theileria orientalis (Ikeda) could be identified in samples of commercial red deer (Cervus elaphus), horses, and working farm dogs in New Zealand. Methods: Blood samples were collected during October and November 2019 from a convenience sample of red deer (n = 57) at slaughter. Equine blood samples (n = 50) were convenience-sampled from those submitted to a veterinary pathology laboratory for routine testing in January 2020. Blood samples, collected for a previous study from a convenience sample of Huntaway dogs (n = 115) from rural regions throughout the North and South Islands of New Zealand between August 2018 and December 2020, were also tested. DNA was extracted and quantitative PCR was used to detect the T. orientalis Ikeda major piroplasm surface protein (MPSP) gene. A standard curve of five serial 10-fold dilutions of a plasmid carrying a fragment of the T. orientalis MPSP gene was used to quantify the number of T. orientalis organisms in the samples. MPSP amplicons obtained by end-point PCR on positive samples were isolated and subjected to DNA sequencing. The resulting sequences were compared to previously published T. orientalis sequences. Results: There were 6/57 (10%) samples positive for T. orientalis Ikeda from the deer and no samples positive for T. orientalis Ikeda from the working dogs or horses. The mean infection intensity for the six PCR-positive deer was 5.1 (min 2.2, max 12.4) T. orientalis Ikeda organisms/mu L. Conclusions and clinical relevance: Red deer can potentially sustain low infection intensities of T. orientalis Ikeda and could act as reservoirs of infected ticks. Further studies are needed to determine whether na & iuml;ve ticks feeding on infected red deer can themselves become infected. Abbreviations: Cq: Quantification cycle; LOQ: Limits of quantification; MPSP: Major piroplasm surface protein; qPCR: Quantitative polymerase chain reaction

CASE HISTORY:Over a period of 2 months in the spring and early summer of 2021, 13 cases of sudden death in cull ewes due to aortic rupture were diagnosed at a small number of New Zealand abattoirs. CLINICAL FINDINGS:In 12/13 (92%) cases, a large blood clot was present in the thorax, and in one case the blood clot was seen in the tissues dorsal to the heart. There were no obvious signs of external trauma. The pluck (heart and lungs) or fixed aorta was submitted for histological examination in seven cases and in all of these, a tear in the aorta was found. Comparing the microscopic appearance of the proximal aorta in these seven cases to three clinically normal ewes from unaffected farms, the aortic wall thickness appeared thinner in the case ewes than the unaffected ewes. Subjectively, there was increased collagen in the tunica media in 3/7 and decreased elastin fibres in 5/7 case ewes compared to the control ewes. Further investigations on the index farm (where the first cases originated), found that the mean liver and serum Cu concentrations in 10 similarly aged, clinically normal ewes were within the normal reference range for New Zealand sheep. Similarly, the liver Cu concentrations of the seven case ewes were within the normal reference range. DIAGNOSIS:Aortic rupture due to an unknown aetiology. CLINICAL RELEVANCE:Clinicians should be aware of this condition as a differential diagnosis for sudden death in older sheep and to assist the Ministry for Primary Industries in establishing the extent of this problem in New Zealand.

The liver fluke Fasciola hepatica is a trematode parasite of farmed livestock with worldwide distribution, causing chronic production losses and possible death from hepatobiliary damage. The effective management of liver fluke infection requires diagnostic tests which can accurately identify infected animals at both the individual and herd level. However, the accuracy of liver fluke diagnostic tests performed on individual New Zealand cattle is currently unknown. The aim of this study was to use a Bayesian latent class model (LCM) to estimate the test characteristics of three liver fluke diagnostic tests, the Coproantigen ELISA, the IDEXX antibody ELISA and the faecal egg count. One hundred and twenty dairy cows each from two dairy farms were blood and faecal sampled in April 2021. The samples were transported to Massey University, Palmerston North, and the three diagnostic tests completed following the respective manufacturer instructions. A Bayesian LCM model, adapted from the original Hui and Walter 2 tests 2 populations model, was built to estimate the test characteristics of the three diagnostic tests in the two dairy herds. The model was implemented in JAGS using Markov chain Monte Carlo sampling. The first 30,000 iterations were discarded as burn-in, and the next 200,000 iterations were used to construct the posterior distributions. Uninformed priors, beta (1,1), were used as the prior distributions for the prevalence estimation and informed beta priors, based on published results, were used as the prior distributions for estimating the sensitivity and specificity of each diagnostic test. Model convergence was confirmed by inspection of trace plots and examination of the results of the Gelman and Rubin test. The results found that the coproantigen ELISA test was the most accurate for diagnosing liver fluke infection in individual animals with a sensitivity = 0.98 (95% CI 0.95 -1.00) and specificity = 0.95 (95% CI 0.81 -1.00) compared to the IDEXX antibody ELISA test, sensitivity = 0.39 (95% CI 0.32 -0.47) and specificity = 0.86 (95% CI 0.75 -0.96) or the FEC, sensitivity = 0.23 (95% CI 0.17-0.30) and specificity = 0.92 (95% CI 0.86 -0.97). Based on these results clinicians should be encouraged to use the coproantigen ELISA test to diagnose liver fluke infection in individual cattle.

CASE HISTORY:A line of 25 cull cows were all found to have ulcerative lesions of the tongue at post-mortem inspection in a New Zealand slaughter plant. A further 9 of 10 cows inspected at the farm of origin had similar oral lesions. There were no other clinical signs or indicators of ill-health observed at ante-mortem inspection in the abattoir or on the farm. The cows had been fed baleage for 3 weeks prior to slaughter, made from pasture in paddocks heavily contaminated with yellow bristle grass (Setaria pumila).CLINICAL FINDINGS:There was extensive and deep transverse linear ulceration in the lingual fossa immediately rostral to the torus linguae. At histological examination, full-thickness ulceration of the stratified squamous epithelium was observed with a bed of disorganised collagenous tissue and extensive mixed inflammatory infiltrate extending into the sub-epithelial connective tissue and skeletal muscle. Barbed plant fragments were embedded in both the superficial and deeper areas of inflammation. Detailed examination of the baleage also found that yellow bristle grass seedheads were present.DIAGNOSIS:Based on the presence of barbed plant material in the tongue and yellow bristle grass seeds in the baleage, a diagnosis of ulcerative stomatitis associated with yellow bristle grass was made.CLINICAL RELEVANCE:Clinicians should be aware of the potential for hay or baleage contaminated with yellow bristle grass to cause oral lesions in cattle.

Reports of neoplasia in deer remain rare (Hill and Staples 1999), despite the conviction that as deer farming became more common, a greater number of pathological processes, including tumours, would be recognised in deer (Pérez et al. 1998). Skin tumours are among the most common neoplasms reported in red deer (Cervus elaphus) and are usually papillomavirus-associated dermal fibropapillomas and papillomas (Erdélyi et al. 2009; Vaatstra et al. 2014; Garcês et al. 2020). Additional reports of cutaneous and subcutaneous tumours in red deer include malignant schwannoma and dermal malignant melanoma (Pérez et al. 1998; Scandrett and Wobeser 2004). In related deer species, subcutaneous dermoid cysts have been described in caribou (Rangifer tarandus) (Wobeser et al. 2009) and cutaneous fibromas in predominantly male white-tailed deer (Odocoileus virginianus) (Berry 1925; Friend 1967; Sundberg and Nielsen 1982). A 17-year-old, 187-kg, castrated, male red deer was examined at the Massey University (Palmerston North, NZ) deer unit on 27 January 2022, with a spherical, deep dermal mass about 3 cm in diameter, raised above the surrounding skin level. The mass was identified on the upper left neck about 7 cm below the base of the left ear, at the angle of the mandible (Figure 1a). At re-examination 1 week later, the mass had almost doubled in size. The mass appeared discrete from the underlying tissue, so a decision was made to remove it that day, while the size of the mass was still manageable. The deer had been abandoned by its mother after dystocia and was hand reared. It had been castrated at a very young age and has resided at the deer unit ever since and been in good health. The deer had been paddocked alone most of its life, excluding short periods when it was paddocked with other deer that had undergone surgical or medical procedures and needed to be separated from the main herd. The animal was placed in a Heenan hydraulic crush (Farmquip Ltd., Napier, NZ) and lightly restrained during the surgery. The sides of the crush were manipulated to give good access to the surgery site. The deer was sedated with 0.2 mg/kg of 5% xylazine (Phoenix Pharm Distributors Ltd., Auckland, NZ) given IM into the neck, and a local anaesthetic block using SC 2% lignocaine (Nopaine 2%; Phoenix Pharm Distributors Ltd.) was placed around the mass. The site was surgically scrubbed and prepared while the local anaesthetic block took effect. An elliptical skin incision was made, and the mass was removed via blunt dissection, with a 1-cm margin (Figure 1b). The wound was closed using simple interrupted suture pattern with 4 metric PDS absorbable suture (Ethicon, Somerville, NJ, USA). Bleeding was minimal and there were no complications during the procedure, although the deer lay down once the crush was opened. The sedation was reversed using 0.2 mg/kg yohimbine IV (Reversal Injection; Phoenix Pharm Distributors Ltd.). Post-operative analgesia was administered using 0.5 mg/kg SC meloxicam (Metacam; Boehringer Ingelheim (NZ) Ltd., Auckland, NZ). No antibiotics were given. The excised mass was placed in 10% buffered formalin and submitted for histology to Massey University (Palmerston North, NZ) Pathobiology Department. The deer recovered well from the surgery. There was slight post-surgical swelling on day 5, which rapidly improved, with no swelling evident 2 weeks after surgery. The mass was sectioned into four and fixed in 10% neutral buffered formalin for 48 hours, processed and embedded into paraffin blocks. Routine H&E stains were performed on multiple 5-μm sections of tissue cut from the formalin-fixed, paraffin-embedded blocks. One section of the mass was additionally stained with Masson’s trichrome and phosphotungstic acid haematoxylin (PTAH). Histological examination revealed an unencapsulated but generally well demarcated deep dermal proliferation of muscle bundles below the overlying haired skin. Muscle bundles were generally of small to medium uniform size, well differentiated, and surrounded and separated by an extensive collagen stroma (Figures 2A and B), confirmed by Masson’s trichrome staining (Figures 2C and D). PTAH staining did not reveal the presence of obvious cross-striations

Aims: To compare the performance of two predictive models for the survival of downer cows. Methods: The first model had been developed in 1987 using a dataset containing missing values, while the second, new model was developed on the same dataset but using modern data imputation and analytical methods. Missing data were imputed using multiple imputation by chained equations and a logistic regression model fitted to the imputed data, with survival or not as the outcome variable. The predictive ability of the model built on the imputed data was contrasted with the original prognostic model by testing them both on a second smaller but complete data set, collected contemporaneously with the development of the original model but from a different region of New Zealand. Sensitivity, specificity, accuracy, and cut point for the two models were calculated. Results: The original 1987 model had a slightly higher accuracy than that of the new one with a sensitivity of 0.85 (95% CI = 0.72-0.94) and a specificity of 0.82 (95% CI = 0.7-0.91), using a cut point for the probability of survival = 0.313. Conclusions: The original prognostic formula published by Clark et al. in 1987 performed as well as a modern model built on an imputed data set.

Aims To collect baseline data from New Zealand sheep farmers on techniques for docking and castrating lambs, their perceptions of the level of pain lambs experience following these procedures, and their opinions about the use of pain relief. Methods From a voluntary cross-sectional survey of New Zealand sheep farmers, descriptive statistics were provided for quantitative study variables. Thematic analysis was performed on the free-text comments. Univariable logistic regression was used to assess factors associated with farmers indicating they would consider using a device allowing administration of pain relief simultaneously with castration and tail docking. Results There were 432 survey responses containing sufficiently complete data for analysis. Of the 340 individuals (77.5%) always or sometimes performing castration of ram lambs, 242 (72.2%) used rubber rings for complete castration, 23 (6.9%) used the short scrotum method for cryptorchid castration, and 75 (22.4%) used a combination of both methods. Of the 423 individuals (97.9%) who indicated that they always or sometimes performed tail docking, 245 (57.9%) used a hot iron only, 148 (35.0%) used a rubber ring only, 26 (5.8%) used both methods, 3 (0.7%) used a surgical knife, and 1 (0.2%) provided no response. Less than 2% of respondents always or sometimes used pain relief for these procedures. Of the 432 respondents, 139 (32.2%) and 180 (41.7%) strongly agreed that castration and tail docking do not cause sufficient pain to warrant using pain relief, respectively. Time and cost were identified as major barriers to providing pain relief. In the unadjusted logistic regression analyses, respondents who were female, had high levels of education, had been farming < 20 years, who believed lambs experienced high levels of pain following the procedures, and who believed pain lasted longer than 6 hours, were more likely to indicate willingness to use pain control devices.

Case history Serum and liver samples from 35, 2-year-old dairy heifers that had fractured one or both humeri post-calving between July and December 2019 were submitted to a diagnostic laboratory for analysis. Serum samples were analysed for albumin, beta-hydroxybutyrate (BHB), creatinine, Ca, Mg, phosphate, non-esterified fatty acids (NEFA), and serum Cu concentration. Liver samples were analysed for liver Cu concentration. Data were compared to published reference intervals. Data values for heifers that prior to fracture had grazed fodder beet were also compared to values for those that had grazed pasture. Clinical findings Sixty-nine percent of heifers with humeral fracture had serum creatinine concentrations below the lower value of the reference range (55-130 mu mol/L). In 3/32 (9%) heifers, serum NEFA concentrations were increased above the reference value indicating body fat mobilisation (>= 1.2 mmol/L for peri-partum cows) and in 20/35 (57%) heifers BHB serum concentrations were above the reference value indicating subclinical ketosis (>= 1.1 mmol/L for peri-partum cows). In 24/35 (69%) heifers, liver Cu concentration was low (<= 44 mu mol/kg) or marginal (45-94 mu mol/kg). The concentration of Cu in serum was low (<= 4.5 mu mol/L) in 2/33 (6%) heifers and marginal (4.6-7.9 mu mol/L) in 5/33 (15%) heifers. There was moderate positive correlation between the logged concentrations of Cu in paired liver and serum samples, r((31)) = 0.43; (95% CI = 0.1-0.79; p = 0.014). One heifer had a serum phosphate concentration below the lower limit of the reference range (< 1.10 mmol/L). For all heifers, the concentrations of albumin, Ca, and Mg in serum were within the reference intervals (23-38 g/L, 2.00-2.60 mmol/L, and 0.49-1.15 mmol/L respectively). Over winter, 15/35 (43%) heifers grazed predominantly pasture, 14/35 (40%) grazed fodder beet and 6/35 (17%) had a mixed diet. Abbreviations BHB: ss-hydroxybutyrate; NEFA: Non-esterified fatty acids

Aims: To investigate the effect of parenteral vitamin B-12 supplementation on the growth rate of dairy heifer calves over the summer and autumn on seven farms from the Central Plateau of New Zealand, an area historically associated with low cobalt levels in grazing pasture.Methods: This was a controlled clinical trial conducted on a convenience sample of seven farms with young female calves randomly assigned to three vitamin B-12 treatment groups and followed through a grazing season. Two treatment groups received either monthly SC injections of a short-acting (SA) B-12 formulation or 3-monthly injections of a long-acting (LA) B12 formulation and the third group received no treatment (NT). No additional parenteral vitamin B12 was given; however, all calves received additional cobalt (0.04-0.4 mg Co/kg liveweight) in the mineralised anthelmintic drenches given orally every month. Liveweight was recorded in December/January and at the end of the trial in May/June/July depending on farm. Pasture cobalt concentrations (mg/kg DM) were measured every month using 500-g herbage samples from 100-m transects in the area about to be grazed by the trial groups.Results: There was evidence for a difference in growth rate between groups with mean final weight of 228 (95% CI = 212-243) kg for the LA groups, 224 (95% CI = 209-239) kg for the SA groups and 226 (95% CI = 211-241) kg for the NT groups respectively, (global p-value = 0.014). Calves given SA vitamin B-12 were 3.77 (95% CI = 0.71-6.82) kg lighter than calves given LA vitamin B-12 (p = 0.011). There was no evidence for a change in pasture cobalt concentrations (p = 0.32).Conclusions and clinical relevance: The results of this trial raise the question as to whether the routine use of vitamin B-12 supplementation in young cattle from areas traditionally thought to be cobalt deficient is necessary, and further raise the possibility that vitamin B(12)supplementation by repeated injection of SA products may negatively impact growth rates.

Aims To evaluate the effect of sporidesmin toxicity on production outcomes and serum biochemistry analytes in mixed age Romney ewes, using a standardised measure of liver damage. Methods This was a prospective longitudinal study following 46 mixed age Romney ewes from sporidesmin intoxication in April 2019, to slaughter 8 months later. The ewes were blood-sampled up to eight times, with a panel of serum biochemistry tests performed on the final six samples. However, only gamma-glutamyl transferase (GGT) activity was measured in the first two samples collected at the end of sporidesmin intoxication and 2 weeks later. Body condition score, ewe weight and production data were also recorded. Using a standardised liver score, based on histology of liver samples collected at slaughter, ewes were assigned to one of three liver disease categories (LDC); low, middle, and high. These were then used as the outcome or predictor variables for statistical analyses. Finally, two separate decision tree models, using recursive partitioning (RP), were fitted to the biochemistry data and to the GGT data collected at FE outbreak, to predict ewes in the low LDC. Results There was no evidence of a difference for the effect of LDC on ewe weight (p = 0.86) with ewes, on average, gaining weight to weaning. Weaning percent, lamb rearing percent and ewe flock efficiency were lower in ewes with high LDC, and scanning-to-weaning lamb loss was significantly higher in sheep with high LDC (p = 0.02). Serum activities of GGT and glutamate dehydrogenase and concentration of globulin were significantly lower in sheep with low LDC than in sheep with middle or high LDC (p < 0.05). However, there was no evidence of a difference for the effect of LDC on other biochemistry variables (p > 0.05). The final RP model for the biochemistry data categorised ewes as low LDC if their GGT was <122 IU/L, 3 months after sporidesmin intoxication, or if their GGT was <514 IU/L,

Osseous sequestration is a common orthopaedic condition of horses and cattle (Firth 1987), and is frequently associated with trauma that results in cortical ischemia and bacterial invasion (Huber 2011). Although deer were introduced into New Zealand in the nineteenth century (Husheer et al. 2003), commercial deer farming itself only became legal in New Zealand in 1969 following the introduction of the New Zealand government’s Noxious Animals Amendment Act 1967 and the Deer Farming Regulations 1969 (Challies 1991). Interest in deer farming increased rapidly in the early 1970s (Pollard and Wilson 2002), with exports of venison, antler, and by-products now worth around NZD$240 million for the year ended September 2020 (B+LNZ 2021). Most of the deer farmed in New Zealand are Cervus elaphus, including the European red deer, North American wapiti, and their hybrids, with a smaller number of fallow deer (Dama dama) also farmed (Mason 1994). There have been a small number of reports of musculoskeletal problems in New Zealand deer including fractures (Wilson 1981; Audigé et al. 2001), osteochondrosis secondary to copper deficiency (Thompson et al. 1994; Audigé et al. 1995), angular limb deformities (Beatson et al. 2011), epiphysitis and osteomyelitis (Badger 1982), foot abscesses (Wilson 1981), polydactyly in red and sika deer (Daniel 1967; Davidson 1971) and outbreaks of lameness associated with Bacteroides nodosus (Skerman 1983) and Fusobacterium necrophorum (Ingram and Gill 2010). However, there have been no reports of bone sequestra in deer in New Zealand, and a literature search conducted using the search terms “deer AND sequestrum AND lameness” in Web of Science on 12 January 2022, found no further results from overseas. On 13 August 2021 a rising 1-year-old (R1) red deer hind weighing 86 kg with a body condition score (BCS) of 2.5/5 presented with severe lameness of the right rear leg. The hind was part of a group of 55 weaned R1 deer, grazing at pasture. Examination of the leg identified a soft, painful swelling on the medial aspect of the metatarsal bone, mid-way between the hock and fetlock. The swelling was not freely movable and seemed adherent to the underlying bone, no crepitus or mobility was noticed on palpation or manipulation of the metatarsus. Differential diagnoses included osteomyelitis with or without bone sequestration, incomplete fracture, and neoplasia although this was less likely due to the patient’s signalment. Radiographic imaging of the leg was sought to confirm the diagnosis. However, the SARS-CoV-2 lockdown response mandated by the New Zealand Government (https://www.health.govt.nz/) meant this had to be postponed until after restrictions were lifted. The deer was treated with 20 mg/kg S/C oxytetracycline (Bivatop 200 Injection, Boehringer Ingelheim (NZ) Ltd., Auckland, NZ). One month later, lockdown restrictions eased, and imaging could be conducted. Two views of the right metatarsus were obtained while the hind was standing and minimally restrained, including mediolateral and plantarodorsal views centred at the mid-diaphyseal region. In addition, there was now a discharging fistula present (Figure 1A). The firm swelling and pain response had increased markedly since first examination, consistent with the periosteal reaction. The results of the radiograph confirmed the presence of an osseous sequestrum, and osteomyelitis (Figure 1B) and arrangements were made to perform a sequestrectomy. The hind was treated again with 20 mg/kg S/C oxytetracycline and this was repeated 3 days later. One week after the radiograph was taken, the hind was sedated with 0.8 mg/kg 5% xylazine (Phoenix Xylazine 5% injection; Phoenix PharmDistributors Ltd.), Auckland, New Zealand) given by I/M injection into the neck. Once recumbent a tourniquet was placed just below the hock, and the leg clipped. The tourniquet remained in position throughout the surgery. Intravenous regional anaesthesia using 5 mL 2% lignocaine (Nopaine 2%, Phoenix Pharm Distributors Ltd.), diluted to 20 mL with sterile water, was injected under pressure into a superficial vein identified on the anterior lateral aspect of the metatarsus, using a 19-gauge butterfly needle. A total of 15 mL of diluted lignocaine was injected. The site was surgically scrubbed and prepared whilst the I/V regional anaesthesia took effect. An elliptical skin incision was made longitudinally around the fistula using a number 15 scalpel blade. Blunt dissection was then used to extend the incision to the periosteum, using the fibrous tissue surrounding the fistula as a guide to locate the sequestrum. The skin edges were retracted using a small Gelpi retractor. A mallet and 6-mm osteotome were then used to remove sufficient periosteal new bone from the cloaca (the cavity in the bone surrounding the sequestrum) to allow removal of the sequestrum using haemostats (Figure 1C). The bone sequestrum measured 30.0 mm × 11.2 mm× 4.9 mm (Figure 1D). The operation site was then flushed with sterile normal saline (Baxter Sodium Chloride for Irrigation; Baxter Healthcare Ltd, Auckland, NZ) and the edges of the wound loosely opposed using Glycolide & eCaprolactone (SilverGlide Pty Ltd, Castle Hill, NSW, Australia) gauge 1–0 suture material. A Robert Jones pressure bandage was then placed over the surgery site, encompassing the whole lower limb, including the foot, and removed 4 days later. At completion of

Theileria orientalis is a tick‒borne intracellular parasite of red blood cells that causes severe and mild infections in various ruminants worldwide. To date there have been 11 types identified within this species, of which 4 types are presently found in New Zealand cattle. Since 2012, New Zealand has suffered a substantial epidemic of infectious bovine anaemia in both dairy and beef cattle associated with the Ikeda type. The speed at which the disease spread through the North Island suggested that other species could have been involved in transmission. The aim of a series of related experiments was to test the null hypothesis that sheep cannot maintain T. orientalis Ikeda type infection or infect ticks that feed on them. Several studies were conducted over 2 years to address this hypothesis which together showed that sheep can have detectable levels of T. orientalis Ikeda type infection in both the acute and chronic phase and that Haemaphysalis longicornis larvae can become infected when feeding on sheep. No anaemia, weight loss or clinical disease was recorded in the sheep in the acute phase of infection. The levels of infection recorded in the sheep were much lower than those found in cattle, consistent with the sheep being asymptomatic carriers of T. orientalis Ikeda type infection.

Reports of congenital oral tumours in New Zealand cattle are extremely rare. In a review of 372 bovine neoplasms referred to Ruakura Veterinary Diagnostic Station from 1955 to 1968 only one congenital oral tumour was described (Shortridge and Cordes 1971). This was a mastocytoma of the tongue, reported as an incidental finding in a 2-week-old calf (Dodd 1964). Worldwide, reports of congenital oral tumours are equally sporadic. A literature search in Web of Science, on 3 June 2020 using the search terms “congenital AND gingiva OR mouth OR oral OR tongue AND tumour OR growth OR hamartoma AND calf OR calves” retrieved only seven peer-reviewed papers. However, when reported, the majority of these tumours tended to be vascular in origin, and were often diagnosed as vascular hamartomas, with a predilection for the rostral mandibular gingiva (Nourani et al. 2007; Doğan et al. 2013; Hashida et al. 2017). Haemangiosarcomas have also been reported, but are much rarer (Azizi et al., 2017). This case study describes the occurrence of a congenital gingival vascular hamartoma in a calf, and to the authors’ knowledge is the first report of this type of tumour in a calf in New Zealand. A female Jersey x Holstein Friesian calf, weighing approximately 50 kg, born 22 July 2019, from a 900cow commercial dairy farm in the Waikato region, was presented for veterinary examination 4 days later. At 3 days of age, the calf was observed having difficulty suckling and a gingival mass was noted by farm staff. Gross examination of the oral cavity revealed a 3 × 1.5 cm, dark pink, lobulated mass located on the left rostral side of both the buccal and lingual aspects of the mandibular gingiva (Figure 1a). Three incisor teeth were affected, with the second incisor being markedly displaced cranio-medially. Although there was no ulceration present, the mass was friable and minimal trauma resulted in copious bleeding. The calf was sedated with 0.4 mg/kg xylazine I/M (Phoenix Xylazine 2% Injection; Phoenix Pharm Distributors Ltd, Auckland, NZ) and the gingiva desensitised by local infiltration of 0.6 mg/kg lignocaine (EALopaine 2%; Ethical Agents Veterinary Marketing Ltd, Auckland, NZ). A single circumferential nylon (Supramid USP 3 + 4; Serag-Wiessner KG, Naila, Germany) ligature was placed around the base of the mass. Sedation was reversed using I/V 0.3 mg/kg tolazoline (Akorn Tolazine Injection; Caledonian Holdings Ltd, Auckland, NZ) and postoperative analgesia provided with S/C 0.5 mg/kg meloxicam (Metacam 20 mg/mL for Injection; Boehringer Ingelheim Animal Health NZ, Auckland, NZ). After the placement of the ligature, the calf recovered the ability to suckle and appeared to grow at a similar rate to its peers, as assessed visually. However, when the calf was re-visited 2 weeks later, the mass was still present, and the ligature had loosened. The calf was again sedated with xylazine and local infiltration performed as before and an attempt was made to remove the mass using portable cryotherapy (Histofreezer; OraSure Technologies Inc, Bethlehem, PA, USA), combined with surgical resection. Unfortunately, the cryotherapy proved ineffective for haemostasis and the surgery was curtailed. Instead, a decision was made to pursue the intensive use of nylon ligatures, using two ligatures instead of one, in order to decrease vascularity and size of the mass. As described previously, sedation was reversed with tolazoline, and meloxicam was given for analgesia. The two ligatures were regularly replaced every 5–7 days by a veterinarian, using the method described, to ensure that they remained tight enough to restrict blood supply. After 1 month of treatment, when the calf was 7 weeks old, it was considered that the mass had decreased sufficiently in size to attempt surgery again. Although smaller, the mass was still highly vascular and was now associated with severe lip distortion. The calf was again sedated with xylazine as described above, and a left mental nerve block performed using 0.3 mg/kg 2% lignocaine. The bulk of the tissue mass was resected using a number 22 scalpel blade and a portable thermocautery unit (Statham Instruments Inc., Oxnard, CA, USA), which provided excellent haemostasis. Sedation was reversed using tolazine, as above. Post-operatively the calf was given a single I/M dose of 2.5 mg/kg flunixin (Flunixin Injection; Norbrook NZ Ltd, Canterbury, NZ) and 24,000 IU/kg long-acting penicillin (Intracillin LA; Virbac, Hamilton, NZ) was also administered I/M which was repeated 3 days later. In addition, the calf was given I/M 3.75 mg/kg ketoprofen (KetoMax 15%; Agrihealth NZ Ltd, Auckland, NZ), daily for 4 days, commencing 24 hours after the surgery. The calf made a full recovery and no significant postoperative bleeding was observed. Over the