New Zealand veterinary journal最新文献

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 Manawatū-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 Manawatū-Whanganui regions) age-matched with 14 control bone samples (all from the Manawatū-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.

Aims: To determine the major causes of mortality in weka (Gallirallus australis), and to investigate associations between causes of mortality and captivity status, age, sex, decade of submission, and season.

Methods: Necropsy records were obtained from the Massey University School of Veterinary Science/Wildbase Pathology database (Palmerston North, NZ) for weka submitted between 1 January 1995 and 22 March 2022. Causes of mortality were classified into categories based on aetiology. Frequency of diagnosis was tested for association with region of submission, captivity status, age, sex, decade, and season of death.

Results: A total of 156 necropsy reports were included in this study, of which 96 (61%) were from wild weka, 57 (36.5%) were captive, and three (1.9%) were of an unspecified captivity status. Weka were submitted from 12 regions across New Zealand. There were 65 (41.7%) adults, 16 (10.3%) juveniles, and 75 (48.1%) weka of an undetermined age among the 156 submissions. Of the weka with a known sex, there was a similar distribution between sexes with 27 (17.3%) males and 29 (18.6%) females. A cause of death was determined in 132/156 (84.6%) cases, with 24/156 (15.4%) cases having an unknown diagnosis. The leading cause of mortality in weka was traumatic injury, which occurred in 65/156 (41.7%), followed by infectious and/or inflammatory diseases in 26/156 (16.7%), and degenerative and/or nutritional conditions affecting 20/156 (12.8%) cases. The distribution of the primary causes of death was found to be dependent on captivity status (p < 0.001). Traumatic and toxic causes of death were more frequent in wild than captive weka. The cause of death was also dependent on season (p < 0.001). There was a significant difference in cause of death between summer and all other seasons (spring p =0.008; autumn p < 0.001; winter p < 0.001) and between autumn and winter (p = 0.008).

Conclusion: Trauma was identified as the most significant cause of mortality in the free-living weka necropsied. The inherent and uncertain submissions biases, and low case numbers over a long period of time, means that temporal patterns and the effect of captivity status on causes of mortality should be interpreted with caution.

This review summarises up-to-date research on the diagnosis of gastrointestinal nematode (GIN) infection in livestock and anthelmintic resistance in GIN. It was commissioned to assist funding bodies to prioritise and guide research and extension efforts to improve the health, welfare and productivity of grazing ruminants in the face of challenge with GIN. A comprehensive review of published articles from journals, books and websites was undertaken, with a focus on peer-reviewed articles published between 2000 and 2024 involving genera of GIN in grazing sheep and cattle with economic importance to New Zealand. Suggestions for articles to include were received from 14 experts in GIN diagnostics. This review is a summary of a longer report submitted to the sponsoring organisation. Clinical signs of GIN infection in grazing ruminants in temperate grazing systems are inadequate as triggers for management interventions including anthelmintic treatment as they are visible only after economically significant pathological changes have occurred. Livestock producers benefit from monitoring GIN burdens using faecal egg counts (FEC) or associated signals such as weight gain. In future, they may use remote monitoring devices for activity in animals, as well as estimating pasture larval contamination. Methods of diagnosing GIN infections using automated FEC devices have improved the convenience of monitoring parasite burdens compared with traditional laboratory methods. However, a lack of quality control measures and a gap in training of skilled technicians for larval differentiation may lead to a shortage of diagnostic capability. Current methods of diagnosing anthelmintic resistance, particularly FEC reduction tests, are not likely to be replaced by laboratory assays in the near future and attention should be focused on facilitating application of new FEC technologies for both animal monitoring and resistance diagnosis. Extension and application of currently available methods and technology will improve animal health and productivity in ruminant grazing systems in the short term. Adoption of novel technologies for remote animal monitoring, practical tools for estimating pasture larval contamination and promoting genetic selection for immunity and resilience to GIN in both sheep and cattle will further enhance productivity in the long term.

There is a large and growing body of literature proposing that there are benefits to employees and workplaces when pets are allowed to accompany their owners to work. This article reports a scoping review of research that is workplace-based and that provides information on the reported benefits or problems of allowing employees' pets at work. The databases Scopus, Discover and Google Scholar were searched with the initial search terms "pets AND workplace AND research." Results were reviewed initially by title to remove items where, for instance, "PET" was used as an acronym. Studies were included if they provided information on research into human well-being and/or work or task performance and pets at work. This included research into the presence of pets while working from home, as the home can be considered a workplace in this situation. A total of 189 papers on pets at work were identified from the searches. The abstracts were reviewed and papers that did not report research into the benefits and challenges of employees' pets at work were excluded, leaving 31 results. The majority of studies used survey methods and did not include validated psychometric measures of key variables including stress. Findings indicated that the presence of employees' pets at work may reduce stress and lead to more positive work-related attitudes, but these findings may not apply to all employees or all workplaces. Negative aspects of pets in the workplace include health risks to humans and animals, cultural concerns and dislike or fear of some animals, and the proportion of participants who raised these concerns or agreed with them varied widely between studies. However, there is little evidence on the prevalence of risks or how they are addressed, and there was no data on how work performance, absenteeism or staff turnover were related to pet-friendly policies at work. More research is required, and some directions for future research are suggested.

Case history: A 4-month-old male Shih Tzu dog (Case 1) and an 11-month-old female Devon Rex cat (Case 2) were referred to specialist veterinary hospitals for evaluation of right thoracic lameness and growth abnormality in the distal aspect of the forelimb.

Clinical findings: Non-weight-bearing lameness and decreased range of motion were noted in the affected limbs of both cases. Case 1 had a plantigrade stance, and a cleft separation between the first and second digits extending upwards to the distal third of the antebrachium. There was no pain on palpation, and the affected limb was shorter than the contralateral. Radiographic examination revealed cleft separation between metacarpal bones I and II, and carpal bone fusion (I, II, III), and the distal radius ended freely and was attached to the first metacarpal bone.Case 2 had a small cleft medial to metacarpal III. The limb was consistently held in abduction and had marked carpal varus. The limb had never been used for weight bearing. Radiographic examination showed agenesis of metacarpal bone II and separation of metacarpals I and III. The radius and ulna were separated and the radial head did not articulate normally at the elbow, leading to marked elbow incongruity.

Diagnosis: Ectrodactyly in both cases.

Treatment and outcome: Amputation of the radius followed by ulnocarpal arthrodesis were performed in both cases. Follow-up evaluations up to 1 year (Case 1) and 10 weeks (Case 2) after surgery indicated satisfactory arthrodesis fusion, owner satisfaction, and a good clinical outcome.

Clinical relevance: Ectrodactyly is a rare congenital deformity of the forelimb with a heterogeneous character, requiring an individualised treatment plan. These are the first cases reported in the literature of ectrodactyly in small animals that were treated successfully with ulnocarpal arthrodesis. This case series therefore provides evidence in support of this treatment option for this heterogeneous congenital deformity.

Case history: In 2023, the New Zealand Department of Conservation seized 63 endemic reptiles that were being held without a permit. This group included three adult female West Coast green geckos (Naultinus tuberculatus) that had been illegally removed from the wild 2 years earlier. They had been held in an outdoor enclosure with a pair of goldstripe geckos (Woodworthia chrysosiretica).

Clinical findings: On physical examination, all three geckos had at least two soft palpable masses in the coelom. Repeated ultrasonographic examination over several months confirmed the diagnosis of pre-ovulatory follicular stasis (POFS) in each gecko, and in subsequent weeks, more ovarian follicles developed in each animal.

Laboratory findings: All three geckos were negative on culture of cloacal swabs for Salmonella spp., and negative on PCR assay of a cloacal flush for Cryptosporidium spp., despite other reptiles in the seized group showing positive results for multiple Salmonella spp., and one other gecko being positive for Cryptosporidium parvum, subtype IIcA5G3.

Treatment and outcome: For all three geckos, para-midline ventral coeliotomy was performed under general anaesthesia, and folliculectomy of degenerate ovarian follicles was performed. Post-operative complications were seen in all three animals, which developed suture-line infections following disruption of normal skin shedding and entrapment of shed keratin in the surgical sites. A second surgery was undertaken to remove impacted keratin and caseous inflammatory material from the surgical wounds of all three animals and buried sutures were placed to close the coelomic wounds. The geckos were treated with 20 mg/kg ceftazidime IM every second day for 2 weeks post-operatively. Subsequent ecdysis (skin shedding) occurred without complication and the geckos were released back to the wild 10 months after admission.

Clinical relevance: The recommended treatment for POFS in reptiles is ovariectomy, which is not appropriate for wild animals. The use of folliculectomy to resolve preovulatory follicular stasis should be considered for animals where retaining reproductive ability is essential.

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.

Aims: To assess agreement of bacterial culture results from samples taken from nasal discharge, the nasal cavity and nasal biopsy from dogs and cats with nasal disease.

Methods: Nineteen dogs and 21 cats with different nasal diseases (chronic rhinitis, n = 30; neoplasia, n = 7; sinonasal aspergillosis, n = 3) were prospectively enrolled in the study. Nasal swabs were taken bilaterally from nasal discharge at the nares, the nasal cavity, and one nasal mucosal biopsy per side. All samples were subjected to aerobic bacterial culture. Kappa statistics were used to evaluate agreement for the most prevalent bacterial species between sampling sites.

Results: A positive culture result for at least one bacterial species was detected in 80% of samples from nasal discharge/nares, 92% of nasal cavity samples, and 75% of biopsy samples. The mean agreement between the three sampling sites for positive vs. negative culture results was never greater than moderate and the precision of the estimates of agreement varied widely.The most frequently isolated bacterial species in dogs were Staphylococcus pseudintermedius, Staphylococcus spp. and Streptococcus spp. In cats, Pasteurella spp. and Staphylococcus felis were the bacterial species cultured most frequently.For the most prevalent cultured species, Staphylococcus spp., mean agreement between sites was never greater than fair and the precision again varied widely.

Conclusion: This study indicates that bacterial culture results in feline and canine nasal disease are site-specific and there was no evidence from this study for consistency between sites within a patient for many bacterial species. Consequently, if bacterial culture results from nasal swabs are used to guide therapeutic antimicrobial choice, different treatments may be selected depending on the site of culture. As a consequence, there is no evidence from this study that nasal bacterial cultures should be recommended as a routine diagnostic measure.

Aims: To obtain preliminary data on changes in gait from the use of a green-lipped mussel (Perna canaliculus) extract product in working farm dogs with musculoskeletal abnormalities using accelerometry.Methods: New Zealand working farm dogs (n = 32) with signs of musculoskeletal abnormalities were enrolled in a double-blinded, placebo-controlled cross-over study. Each dog was allocated to one of six groups to receive three trial substances (180 mg full fat green-lipped mussel extract (GLME₁₈₀); 220 mg full fat green-lipped mussel extract (GLME₂₂₀); placebo) in one of the six possible different orders. Each trial substance was administered orally once a day for an 8-week period, with a 4-week washout in between each. Dogs wore a collar-mounted triaxial accelerometer for the study duration. Diet and activity were not controlled. Accelerations were recorded continuously and analysed (n = 27) in 10-second activity epochs partitioned into daytime and night-time periods. Analysis of activity during the daytime period was limited to epochs when dogs were gaiting faster than a walk. The median and IQR of activity were determined for the daytime and night-time. Additionally, the 75th and 90th percentiles of daytime activity for each 24-hour period were determined. Mixed effects linear regression models were constructed to determine if each trial substance altered the response variables.

Results: During the daytime, the 90th percentile was higher when dogs were given GLME₂₂₀ compared with the placebo (β coefficient 2.6; 95% CI = 0.25-4.94; p = 0.03). Dogs that started the trial with the GLME products had a higher 90th percentile activity compared with dogs that began with the placebo (β coefficient 26.26; 95% CI = 0.45-52.06; p = 0.046). The 75th percentile for activity was not affected by the GLME product. The daytime IQR was larger when dogs were given the GLME₁₈₀ product compared with the placebo (β coefficient 1.25; 95% CI = 0.12-2.37; p = 0.03). Night-time median activity and the IQR was greater in dogs that started the trial with the GLME products than in dogs that began with the placebo. The night-time IQR for activity was greater for GLME₁₈₀ than for the placebo.

Conclusions: Administration of a low dose of the GLME-containing product increased peak activity in working farm dogs with signs of musculoskeletal abnormalities and may improve their performance.

Clinical relevance: Even mildly affected working farm dogs might benefit from support of their musculoskeletal abnormalities, and this particular GLME-based product shows promise as an adjunct to other management strategies.

Aims: To investigate the effect of injection of trace mineral supplement (TMS) 14-28 days before calving on white blood cell count (WBCC) and function, serum antioxidant capacity (SAC) and reactive oxygen species (ROS) in pasture-fed cattle after calving.

Methods: On each of two South Island, seasonally calving, pastoral dairy farms,1 month before dry-off, a random sample of 150 multiparous cows predicted to calve within 7 days of the herd's planned start of calving (PSC) were stratified on individual somatic cell count, age, breed and expected calving date. On each farm, 14-24 days before PSC, 60 selected cows were randomly assigned for TMS (Zn, Mn, Se, Cu) injection, and 60 were controls. All 240 cows were contemporaneously injected with hydroxocobalamin, and controls with Se. Blood samples were collected pre-injection and 3, 12 and 40 days after calving. Phagocytic activity, count and proportion of neutrophils, lymphocytes and monocytes, WBCC, ROS, SAC were measured. Plasma concentrations of Se, Cu and glutathione peroxidase (GPx) were monitored from a random subset of animals. Differences attributable to TMS were estimated using mixed-multivariable Bayesian analysis, expressed as mean and highest density interval (HDI).

Results: Three and 40 days after calving, TMS-treated cows had 0.36 (90% HDI = 0.00-0.77) x 10⁹ and 0.25 (90% HDI = 0.00-0.55) x 10⁹ fewer neutrophils/L. Neutrophils comprised 6 (90% HDI = 0-11)% and 4 (90% HDI = 0-8)% less of the WBCC, and the neutrophil count was 14 (90% HDI = 0-27)% and 9 (90% HDI = 0-18)% less than controls. However, 3 days after calving, there were 7 (95% HDI = 2-12)% more cells phagocytosing and 2,900 (95% HDI = 2,600-3,200) more bacteria ingested/cell. Twelve and 40 days after calving, TMS-treated cows had 0.65 (95% HDI = 0.17-1.17) x 10⁹ and 0.28 (95% HDI = 0.00-0.59) x 10⁹ more lymphocytes/L. Lymphocytes comprised 10 (95% HDI = 3-18)% and 5 (95% HDI = 0-9)% more of the WBCC, and the lymphocyte count was 30 (95% HDI = 11-51)% and 9 (95% HDI = 0-9)% more than controls. There were no meaningful differences in ROS, SAC, ROS/SAC, other white blood cells, or WBCC. Plasma Cu, Se and GPx concentrations were above recommended thresholds.

Conclusions: Pre-calving TMS injection was associated with differences in white blood cell population and function that may reduce the risk of disease.

Abbreviations: BHOB: Beta-hydroxybutyrate; GPx: Glutathione peroxidase; HDI: Highest density interval; MESF: Molecules of equivalent soluble fluorophore; OSi: Oxidative stress index; PSC: Planned start of calving; ROPE: Region of probable equivalence; ROS: Reactive oxygen species; SAC: Serum antioxidant capacity; THI: Temperature humidity index; TMS: Trace mineral supplement; WAIC: Widely applicable information criterion; WBCC: White blood cell count.