CASE HISTORY:On two occasions, increased perinatal losses were reported in two beef cattle herds under extensive rearing conditions in Buenos Aires province, Argentina, during the winter calving season of 2025. CLINICAL FINDINGS:Affected calves were born weak, unable to stand and suckle, and died within 1-3 days of birth. Cumulative incidences of 10% (33/330) and 3.9% (12/305) were recorded, with 100% case fatality. PATHOLOGICAL AND LABORATORY FINDINGS:Necropsies were performed on three calves: two from Outbreak 1 (one calf died within 1 day of birth and one within 3 days) and one calf that died within 1 day of birth from Outbreak 2. Grossly, in all three calves, pelvic limbs and sublumbar muscles exhibited multifocal-to-coalescent pale whitish discolouration, interspersed with haemorrhage. Microscopically, skeletal muscles presented polyphasic degeneration and necrosis of myofibres with calcified deposits within the sarcoplasm. Low Se concentrations (<0.75 mg/kg) were detected in the livers of all three calves, while Cu and Zn concentrations were within reference ranges. No evidence for the involvement of infectious agents was detected. Low Se concentrations were observed in serum samples from 18 dams from Outbreak 1 and nine from Outbreak 2. Mineral analysis of available feed from both farms showed low Cu concentrations in both outbreaks and elevated S concentrations in Outbreak 2. DIAGNOSIS:Nutritional myopathy (NM) in beef calves, presumed to be associated with Se deficiency in calves born to Se-deficient dams. CLINICAL RELEVANCE:Se deficiency was the most likely cause of NM, but high dietary SO4-2 and S concentration in Outbreak 2 may have interfered with dietary Se absorption. Our study highlights that NM should be considered as a potential cause of perinatal losses.
AIM:To evaluate the efficacy of an inactivated, whole-cell Leptospira borgpetersenii serovar Tarassovi vaccine for prevention of urinary shedding of L. borgpetersenii strain Pacifica, in naturally challenged cattle. METHODS:Three dairy farms in Northland, NZ, endemically infected with Pacifica, participated in a randomised controlled trial. Female calves (n = 291), aged 3-7 weeks, were randomly allocated in equal proportion to vaccinated and control groups. Two doses of test vaccine or saline were administered 4 weeks apart, then booster doses at 6 and 18 months. Blood and urine samples were collected once or twice between weeks 71 and 93, for determination of Tarassovi serology and shedding of pathogenic Leptospira by urine PCR, with subsequent amplicon sequencing of PCR-positive samples. For each farm separately, and pooled results from Farms 1 and 2, the proportion of animals shedding Leptospira in each group was compared statistically, and vaccine efficacy (VE) calculated. RESULTS:A strong serological response to Tarassovi was demonstrated following two vaccine doses. Between weeks 81 and 93, when study heifers were 17-20 months old, a high proportion of unvaccinated controls were seropositive to Tarassovi (100%, 89% and 83% on Farms 1-3, respectively), consistent with exposure to Pacifica on each farm. On Farm 1, 13/30 (43%) controls and 0/29 vaccinates were shedding pathogenic Leptospira in urine, representing VE of 100% (95% CI = 73-100%; p < 0.001); Pacifica was confirmed in eight control animals, also representing efficacy of 100% (95% CI = 49-100%; p = 0.005). On Farm 2, 6/73 (8%) controls and 1/72 (1%) vaccinates were shedding pathogenic Leptospira; however, the difference was not significant (p = 0.116). On Farms 1 and 2 combined, 19/103 (18%) controls and 1/101 (1%) vaccinates were shedding pathogenic Leptospira, representing VE of 95% (95% CI = 70-100%; p < 0.001). On Farm 3, one unvaccinated control was found to be shedding, and no vaccinates. No other serovars of Leptospira were identified on any farm by urine PCR. CONCLUSIONS:The Tarassovi vaccine conferred a very high level of protection (95-100% efficacy) against urinary shedding of L. borgpetersenii strain Pacifica in cattle, following two doses in calves and booster vaccinations at 6 and 18 months. CLINICAL RELEVANCE:Given the serious zoonotic risk of leptospirosis, and the emergence of Pacifica as an important strain in NZ cattle, incorporation of an effective Tarassovi vaccine in standard leptospiral vaccination programmes is highly recommended.
Aims: To characterise the prevalence, severity, and anatomical location of bruising in surplus unweaned calves following commercial transport to meat processing plants and to compare these findings with calves slaughtered on-farm prior to transport. Despite bruising being a recognised welfare concern, data describing its occurrence under commercial New Zealand conditions remain limited.Methods: In 2023, carcasses (n = 5,476) of unweaned calves were assessed at two meat processing plants in New Zealand, one in the North Island (MP1) and one in the South Island (MP2), and one New Zealand pet-food processor (PP1) where calves were slaughtered on-farm. All carcasses were scored by a single trained technician using a standardised protocol that classified bruises ≥ 1.5 cm in diameter by size and anatomical location.Results: Overall, 71% of transported calves had at least one bruise ≥ 1.5 cm in diameter. Calves slaughtered on-farm had markedly lower odds of bruising than transported calves (OR = 0.12; 95% CI = 0.08-0.16), and bruises were generally smaller, with only 4/71 > 5 cm in diameter. Stifle bruising was the most prevalent lesion in transported calves (70% of all carcasses at MP1; 68% at MP2). Among transported calves, the proportion of carcasses with multiple bruises (≥ 4 bruised locations) was lower at MP1 than MP2 (OR = 0.32; 95% CI = 0.19-0.55), indicating between-premises variation in handling or transport conditions.Conclusions and clinical relevance: The inclusion of an on-farm slaughter comparison group provides strong evidence that most bruising arises after calves leave the farm of origin. The high prevalence and consistent localisation of bruising, particularly at the stifle, suggest that transport-related factors such as flooring type, stocking density, and loading or unloading events contribute to traumatic injury in surplus calves. These findings highlight the need for targeted welfare interventions during calf transport, including the evaluation of practical mitigation strategies such as non-slip flooring and increased space allowance, to reduce bruising and improve welfare outcomes for surplus calves.
Johne's disease (JD) is a common endemic gastrointestinal disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). With no effective treatment or vaccine preventing infection, control is currently based on the identification of infected animals and prevention of the spread of infection. The aim of this review is to critically assess the diagnostic tests currently used to detect MAP infection in NZ dairy cattle and to evaluate the current understanding of the host's genetics in preventing the disease. Multiple diagnostic tests for MAP infection, such as ELISA and faecal quantitative PCR, are currently available in NZ, but none are close to a gold-standard test. The lack of new tests in NZ has resulted in the development of multiple testing strategies such as parallel and serial testing with combinations of tests to improve specificity and sensitivity, pooling samples to reduce costs, whole herd testing to optimise culling before drying off, or selection of cows to produce replacements. However, these strategies need further testing to confirm their cost-benefit, especially in relation to varying infection pressures at the individual cow and herd levels. There is limited understanding of how the host's genetic variation contributes to the range of responses - the JD phenotype - seen in animals in contact with MAP. Canonically, this is described in terms of susceptibility, resistance and resilience. However, within field studies, it is very difficult to identify animals with these characteristics. For example, the combination of repeated and combined diagnostic testing, together with longitudinal production data required to identify resilient animals, can be very expensive. This review shows that more NZ-based research is required around strategies that optimise the use and value of what are inevitably imperfect diagnostic tests. Such work should be undertaken alongside a focus on identifying the genetic differences behind the JD phenotypes.
The Paris Agreement requires New Zealand to reduce its overall greenhouse gas (GHG) emissions. As a consequence, there is increased interest in reducing enteric methane (CH4), a major emission source from ruminants such as cattle and sheep. Reducing CH4 is crucial not only for climate commitments but also to meet sustainability demands from global buyers of NZ's agricultural exports. This review summarises current and future technologies for CH4 mitigation, focusing specifically on their applicability to pastoral grazing systems.Enteric CH4 is a natural microbial by-product of feed fermentation in the rumen, formed by methanogenic archaea that use hydrogen and other simple compounds to form CH4. Current mitigation strategies include chemical inhibitors like 3-nitrooxypropanol (3-NOP), bromoform, and naturally brominated compounds in red seaweed (Asparagopsis spp.). These inhibit methanogenesis but require continuous dosing to be most effective, which is challenging in grazing systems. Feed additives such as probiotics and essential oils can reduce CH4 by altering the rumen microbiome, although large-scale application faces logistical hurdles. Forage-based approaches such as high-digestibility or tannin-containing plants can reduce methane yield and excreta GHG emissions. While these may represent a more suitable mitigation strategy for NZ's pastoral systems, research is required into improving their broad-scale adoption across a wide range of climates and soil types. Animal breeding offers a permanent option to reduce methane emissions by selecting for traits that lower CH4 yield or intensity. Early-life interventions during rumen development in calves can potentially induce lasting microbial and physiological changes that reduce methane emissions, although sustained benefits beyond 12 months of age require further investigation.Future solutions include vaccines to produce antibodies targeting methanogens to inhibit methane production, offering a practical and globally applicable mitigation method. Advances in forage genetics, such as tannin-rich clover or lipid-enhanced ryegrass, also show promise but require further research and regulatory changes prior to commercialisation. Concurrently, ongoing improvement of the overall nutritional status of our flocks and herds, to reduce the lifetime GHG footprint, is also required.There is no single mitigation strategy for enteric CH4 that is universally applicable to NZ's pastoral systems. Achieving NZ's sustainability targets while preserving production efficiency and export competitiveness will require an integrated portfolio of mitigation options. This stackable approach should combine dietary interventions, genetic selection, microbial management, and adaptive management practices to jointly reduce emissions without compromising productivity or market access.
CASE HISTORY:Two male, neutered, Domestic Shorthair cats, aged 5 and 8 years, were presented to the University of Florida for evaluation and correction of rectal perforations that occurred during faecal sample collection with faecal loops at their primary care hospitals. CLINICAL FINDINGS:One cat presented with a fever, neutropenia, and lymphocytosis, while the other had a fever, thrombocytopenia, hyperglycaemia, and was approximately 5% dehydrated. In both cases, radiography identified a heterogeneous soft tissue and gas opacity adjacent to the rectum, and CT scans identified a defect in the rectal wall with associated pocketing, subcutaneous faecal material, and subcutaneous emphysema. The rectal defects were repaired surgically in both cats using a lateral perineal approach. Both surgical sites were treated with open wound management and left to heal by second intention. DIAGNOSIS:Iatrogenic rectal perforation. CLINICAL RELEVANCE:There are risks associated with the use of instruments, such as faecal loops or thermometers, in the rectum. Associated trauma can lead to potentially life-threatening complications. Early detection of rectal perforation is vital to reduce further complications and improve clinical outcomes.
AIMS:To evaluate how frequently radiographs, taken during the follow-up period (4-8 weeks) after uncomplicated surgery for the internal fixation of simple transverse or short oblique radius and ulna fractures in small dogs (< 15 kg), resulted in a change to the post-operative management plan, and to evaluate the long-term owner-reported outcomes. METHODS:Medical records of dogs (n = 121) undergoing internal fixation of radius and ulna fractures in a private veterinary referral hospital in Quebec (Canada) were reviewed. Cases with no intra-operative complications, an unremarkable post-operative recovery, and follow-up orthopaedic and radiographic examinations between 4 and 8 weeks post-operatively were included. Data collected included demographic information, fracture details, owner-reported concerns and orthopaedic examination findings at follow-up, radiographic evaluation, and changes in post-operative management with underlying reasons. Long-term owner-reported outcome was also evaluated using the Liverpool Osteoarthritis in Dogs questionnaire. RESULTS:Follow-up radiographs were obtained at a median of 6 (min 4, max 8) weeks post-operatively. At the time of follow-up, 82/121 (67.8%) cases had no owner-reported concerns and no unsatisfactory findings on orthopaedic examination. Radiographic findings led to changes in post-operative recommendations in 2/82 (2.4%) of these dogs. In the 39 cases with owner-reported concerns and/or unsatisfactory orthopaedic findings, radiographic findings led to changes in recommendations in five (12.8%) cases. Major complications at short-term follow-up occurred in 2/121 (1.7%) dogs; both were presented with owner concerns and unsatisfactory findings on orthopaedic evaluation. Based on questionnaire responses, 86/88 (97.7%) dogs had normal function or a very mild impairment 12 months or more after surgery. CONCLUSION:In this population, the findings from follow-up radiography resulted in a change to the post-operative management plan in only a small proportion (2.4%) of cases that did not have concerns identified by clinical examination or reported by the owner. Follow-up radiography did contribute to a more comprehensive understanding of bone abnormalities such as osteopenia. A greater impact of radiographic findings was observed in cases with clinical or owner-reported concerns. CLINICAL RELEVANCE:These findings provide data on the frequency with which radiographic findings alter post-operative management and may inform individualised, clinically driven decisions regarding follow-up imaging.
CASE HISTORY:In summer 2024, an outbreak of Serratia marcescens mastitis occurred in a pedigree Jersey and Friesian herd in the Manawatū region of New Zealand. Before the herd investigation, the farmer reported clinical mastitis (CM) cases that responded poorly to treatment, together with an increase in bulk milk somatic cell count. Initial milk samples collected before the herd visit identified isolates of S. marcescens in three of four cows. Herd records also showed an increase in the monthly percentage of cows treated for CM from 0.8% in December 2023 to 2.9% in January 2024 and 2.1% in February 2024. CLINICAL FINDINGS:A herd investigation was conducted in February 2024. The farmer was using a chlorhexidine-based teat spray system. Cows were selected for sampling on the basis of a very high individual somatic cell count and/or farmer-identified persistent CM, and quarter milk samples were collected aseptically from selected cows after screening using the rapid mastitis test. Additional samples of diluted teat spray, undiluted teat spray, and bore water were also collected for culture. The diluted teat spray was stored in a container in which the withdrawal tube passed through an old teat liner without a water-tight seal, leaving a visible gap around the opening and creating a risk of contamination. LABORATORY FINDINGS:Among the 41 milk samples collected during the herd investigation, S. marcescens was identified in 4/41 samples, Bacillus licheniformis in 15/41 samples, and Streptococcus uberis in 5/41 samples. In addition, 3/41 samples were reported as "no peak found" and 5/41 as "no organism identification possible." Including the three cows with positive pre-visit milk samples, S. marcescens was isolated from seven cows in total. S. marcescens was also identified in the diluted teat spray sample, but not in the bore water or undiluted teat spray samples. DIAGNOSIS:These findings were considered consistent with an outbreak of S. marcescens mastitis, most likely associated with contamination of the in-shed diluted teat spray system. CLINICAL RELEVANCE:Following replacement of the contaminated teat spray and storage container, no new cases were identified. This case highlights the importance of milk sampling, accurate pathogen identification, and prompt investigation of hygiene-related sources when atypical mastitis pathogens are detected.
CASE HISTORY:This retrospective case series describes 15 dogs that developed post-operative complications following open surgical management of pyothorax at four referral centres in Belgium, France, Italy and the United Kingdom that were identified among 34 dogs that underwent surgical treatment for pyothorax from 2015-2023. The study population included a variety of breeds, with mixed-breed dogs (3/15; 20%), English Springer Spaniels (2/15; 13.3%) and Malinois (2/15; 13.3%) most frequently represented. Males (8/15; 53.3%) slightly outnumbered females (7/15; 46.7%). The median age at presentation was 5.7 (min 1.5, max 9) years, and the median body weight was 24.0 (min 11, max 54) kg. All dogs had received medical management for pyothorax before referral, including antibiotic therapy and, in most cases, thoracic drainage. CLINICAL FINDINGS:Computed tomography demonstrated bilateral pleural effusion in 14/15 (93.3%) dogs, with a suspected or confirmed migrating foreign body in three cases. Diffuse pleural inflammation was identified intra-operatively in 13 dogs, fibrinous adhesions in 12 dogs, and necrotic pulmonary or mediastinal tissue in 8 dogs. Intra-operative complications occurred in nearly half of the dogs (7/15; 46.7%), including intra-operative hypotension in five and iatrogenic lung injury in two. TREATMENT AND OUTCOME:Surgery was performed via median sternotomy alone or in combination with cranial celiotomy, and in one dog, it included a concurrent cervical exploration due to the extent of disease present. Post-operative complications were classified using a modified Clavien-Dindo system: six dogs experienced minor complications, six experienced major complications, and three experienced catastrophic complications. Major complications included recurrent pyothorax or persistence of pleural infection in six dogs and a chest wall abscess in one dog, all of which required revision surgery. Two dogs died from catastrophic complications, and one additional dog died following a second revision surgery, resulting in an overall mortality rate of 20%. The median hospitalisation period was 5 (min 4, max 38) days, and no recurrence was reported among surviving dogs at long-term follow-up. CLINICAL RELEVANCE:Post-operative complications following surgery for pyothorax are relatively common and may require intensive management or repeat thoracotomy. These risks should therefore be considered during pre-operative discussions with owners, and warrant careful post-operative monitoring. Despite post-operative morbidity, 12/15 dogs that experienced complications survived and remained free of recurrence during long-term follow-up, indicating that favourable outcomes can be achieved when complications are recognised early and managed appropriately.
AIMS:To explore, using a narrative approach, the experiences of Māori veterinarians and veterinary nurses in their journey into and within the veterinary sector in Aotearoa, New Zealand. METHODS:Seven veterinarians and six veterinary nurses who identify as Māori were interviewed using a snowball sampling method. Semi-structured interviews explored participants' haerenga (journey) into the sector, their experiences within the sector, and their perspectives on opportunities for improvement. Interviews were transcribed and analysed using inductive reflexive thematic analysis. Participants were then invited to review and provide feedback on the emerging themes. RESULTS:Participants shared rich narratives about their pathways into the veterinary sector, their experiences in education, and their time working in the sector. This paper focuses on experiences within the veterinary sector and the opportunities for change identified by participants. Four key themes emerged, each with three sub-themes. The first theme highlighted the minimal presence and visibility of Māori in the sector. The second identified a lack of recognition of te ao Māori, including te reo Māori, tikanga, and Te Tiriti o Waitangi partnership. While some early signs of cultural inclusion were noted, participants saw significant opportunities for improvement across all levels of the sector. The third theme addressed experiences of racism, both direct and observed, within professional settings and interactions with clients. The final theme explored a disconnect between participants' personal values and those commonly practised in the sector. All of these themes can be viewed in the context of the socio-cultural climate that exists in Aotearoa New Zealand. CONCLUSION:This study reveals a lack of cultural safety for Māori in the veterinary workforce, marking a first in sector-specific research. Systemic barriers, under-representation, and undervaluing of Māori knowledge persist. Embedding Te Tiriti and supporting kaupapa Māori leadership are essential. Co-created models of care can improve outcomes for both animals and their human caretakers. CLINICAL RELEVANCE:The findings offer practical guidance for the veterinary sector to improve cultural safety and responsiveness. By increasing awareness of te ao Māori, integrating te reo Māori and tikanga, and embedding Te Tiriti o Waitangi into organisational practices, veterinary professionals and businesses can better serve Māori communities. These changes have the potential to improve client relationships, animal health outcomes, and staff retention - benefiting Māori and non-Māori alike.
CASE HISTORY:A juvenile bottlenose dolphin (Tursiops truncatus) was first observed among a group of approximately 12 dolphins on 10 December 2024, repeatedly breaching off Riverhead, Auckland, New Zealand. On subsequent observations, material consistent with fishing debris was seen entangled around the dorsal fin and tail flukes. While most conspecifics departed the area, a larger dolphin remained in close association with the entangled individual. The pair remained within the local area for at least 29 days prior to human intervention efforts to disentangle the animal. During the interim period, the entangled dolphin exhibited progressive deterioration in body condition and reduced activity compared with the free-swimming conspecific. The animal was found dead shortly thereafter. PATHOLOGICAL FINDINGS:Within 48 hours of death, post-mortem MRI and necropsy were conducted on the cadaver, which was scored as decomposition carcass code 1 (within rigor mortis). These identified an emaciated, sexually immature female bottlenose dolphin. Gross examination revealed severe, multifocal to coalescing lacerations and abrasions affecting the dorsal fin and caudal peduncle, with associated soft-tissue loss and irregular wound margins. Histologically, sections from the dorsal fin laceration showed evidence of severe, subacute to chronic, ulcerative necrosuppurative dermatitis with secondary bacterial infection. Pulmonary tissue samples revealed an acute, severe bacterial pneumonia characterised by neutrophilic infiltration and short bacilli. The liver and spleen showed findings of hepatitis and splenitis, suggestive of bacterial septicaemia. Swab isolates from these pooled tissues identified moderate growth of Erysipelothrix rhusiopathiae and Pseudomonas spp. Collectively, in vivo evidence and post-mortem gross and histopathological findings were consistent with poor body condition resulting from a progressive wasting disease primarily associated with chronic entanglement, leading to chronic active deep infectious necrosuppurative dermatitis and subsequent fatal bacterial septicaemia. DIAGNOSIS:Bacterial septicaemia. CLINICAL RELEVANCE:This case highlights the importance of timely intervention in entanglement events to reduce the risk of secondary complications, including impaired foraging, progressive loss of body condition, and infection. Based on post-mortem findings, death was consistent with bacterial septicaemia in the context of a deep skin lesion to the dorsal fin caused by fishing gear and its subsequent pathological effects. From an animal welfare perspective, the prolonged duration of entanglement, progressive debilitation, and evidence of systemic wasting disease support a period of substantial and sustained welfare compromise prior to death. This incident would be classified as high-intensity, long-duration suffering.
Sheep milking in New Zealand has grown rapidly in the last 20 years. In the 2022-2023 season, a research project conducted on 20 commercial farms (estimated to represent approximately two-thirds of the New Zealand dairy sheep industry) established baseline parameters for udder health and milk quality. This paper synthesises findings from that project alongside relevant international dairy sheep mastitis literature to clarify what is known, what is uncertain, and what actions are most likely to accelerate progress in New Zealand. It proposes immediate, short-term, and medium-term priorities for mastitis control in New Zealand dairy sheep. We set benchmarks for clinical mastitis incidence (< 1.5%), subclinical mastitis prevalence (< 2%), and bulk-milk aerobic plate count (< 5% consignments ≥ 100,000 cfu/mL) and somatic cell count (season mean < 400,000 cells/mL) using the mean of the best 25% of farms. On-farm practices most likely to achieve these benchmarks are summarised, including milk recording, use of the rapid mastitis test, somatic cell count thresholds, milking hygiene methods, and udder conformation scoring. Research priorities include determining the factors associated with high bulk-milk aerobic plate count, clarifying mastitis identification and management when multiple milk-recording events take place within a season, extending the preliminary investigation of mastitis risk factors and treatments, confirming the value of milking hygiene practices, and developing a rapid udder-conformation scoring system.
AIM:To determine the cost-benefit of a control programme that used serological testing of young heifer replacement calves to reduce Neospora caninum seroprevalence in two dairy herds. METHODS:Data were collected between 2016 and 2023 from replacement heifer calf cohorts that were tested at a young age for N. caninum antibodies, on two adjacent Waikato dairy farms with endemic neosporosis. Calf serology (ELISA) results were interpreted using cut-off values adjusted to compensate for the presence of maternal antibodies, to classify calves as seronegative, inconclusive, or seropositive. Serological testing costs to establish the N. caninum status of calves were obtained alongside rearing costs from birth up to the point at which the calves' serostatus was established or, for serologically negative animals, to 24 months of age when replacement heifers are expected to produce their first calf. A formula was developed to calculate a break-even point: when calf testing costs were equal to the financial benefit of not rearing unwanted seropositive replacement heifers. The calculation did not include any potential lifetime costs that could be attributed to abortion or decreased production, but is valid when the farmer's aim is to avoid rearing N. caninum seropositive replacement calves and to eliminate the disease from the herd over time. RESULTS:Testing young heifer replacement calves with an N. caninum antibody ELISA to identify congenitally infected calves was of economic benefit when the proportion of seropositive replacement calves was > 2.87%. A sensitivity analysis showed that the cost of heifer rearing had the greatest impact on the break-even point, followed by the cost of the initial test. CONCLUSION AND CLINICAL RELEVANCE:As the proportion of N. caninum-infected cows in the herd reduces and the proportion of infected calves drops below 3%, young-calf testing is no longer cost-effective, and targeted testing becomes a more economical alternative. For example, monitoring for vertical transmission if valuable seropositive cows are mated to produce a potential replacement calf and checking for horizontal infection by retesting animals that had seronegative results as young calves. When the herd seroprevalence is low, horizontal infection becomes the main route of infection, and biosecurity should be maintained at a high standard. Consideration should also be given to the limitations of the diagnostic tests that are used for monitoring, as these have been developed for adult cattle that have recently aborted due to N. caninum rather than persistently infected animals.
AIMS:To establish a method of measuring diclazuril concentration from kiwi (Apteryx spp.) faeces using liquid chromatography-mass spectrometry (LC-MS), to non-invasively determine drug disposition. METHODS:Daily faecal samples were collected from healthy 3- to 4-week-old captive-reared North Island brown kiwi (Apteryx mantelli) chicks (n = 6) following a single dose of 5 mg/kg bodyweight of the anticoccidial drug diclazuril for a period of 5 days. Daily pooled samples from each bird were prepared for LC-MS using dispersive solid phase extraction to isolate the drug for analysis. The LC-MS assay was validated using linear regression, inter-day and intra-day variation, and recovery analysis. Pharmacokinetic parameters were calculated using non-compartmental analysis. RESULTS:Pharmacokinetic parameters were able to be established for diclazuril from the faeces of five kiwi chicks (three male, two female). Samples from one chick were too low in drug concentration to be analysed. The standard curve for diclazuril was linear from 4 to 20 ng/mg (r2 = 0.9997). The limit of quantification for diclazuril was 1 ng/mL. Extraction recoveries were from 76.8% to 96.6%, with intra- and inter-day coefficients of variation of 3-3.9% and 5-8.7%. The mean peak concentration of diclazuril in faeces was 260.46 (SD 335.77) ng/mg, and the highest concentration of diclazuril was detected at 24 hours following administration. Mean faecal concentrations declined to 2.29 (SD 1.13) ng/mg on Day 5 after administration, with a mean elimination half-life of 23.82 (SD 13.69) hours. The elimination constant was 0.0377 (SD 0.02) h-1, consistent with the previously reported rate in kiwi plasma. CONCLUSIONS:This study establishes that the quantification of diclazuril in kiwi faeces by LC-MS is robust and reliable. Diclazuril exhibits a prolonged elimination half-life in kiwi faeces, supporting its potential for sustained coccidiostatic activity. CLINICAL RELEVANCE:The methods developed here have the potential to be modified to analyse other target drugs from faeces of birds and can assist in the evaluation of efficacy of drug treatment regimes, in particular for drugs that target infection in the gastrointestinal tract, such as anticoccidials. This non-invasive approach will be especially valuable in wildlife species where establishing plasma pharmacokinetics for drug treatments is challenging and can have significant animal welfare consequences.
AIMS:To identify some of the risk factors for dental malocclusion and examine associations between diet, age and sex and the frequency of dental malocclusion in a convenience sample of pet rabbits (Oryctolagus cuniculus) in Lima, Peru, during the period 2021-2022. METHODS:A cross-sectional study of clinical records of 308 rabbits at a private veterinary clinic in Lima, Peru from May 2021 to May 2022 was undertaken. The χ2 test was used to determine the unadjusted associations between variables and the diagnosis of dental malocclusion. Crude prevalence ratios (cPR) and adjusted prevalence ratios (aPR) were calculated using a generalised linear model with a Poisson distribution. RESULTS:The frequency of dental malocclusion in the sample was 75/308 (24.4%). The aPR for dental malocclusion for males was 1.80 (95% CI = 1.10-2.95) times higher compared to females, 1.94 (95% CI = 1.13-3.34) times higher for rabbits > 5 years old (seniors) compared to rabbits < 1 year old (juveniles) and 0.37 (95% CI = 0.25-0.54) times lower for a diet with hay compared to a diet without hay. CONCLUSIONS:Our data and model suggest that senior, male rabbits on a diet without hay would have a higher frequency of malocclusion than female, juvenile rabbits on a diet including hay. After adjusting for age and sex, hay in the diet decreased the occurrence of dental malocclusion. CLINICAL RELEVANCE:Our results contribute to the limited studies about the dental health of pet rabbits and may be a source of information for veterinarians and pet owners who seek optimal pet health and welfare.
AIMS:To evaluate whether landmarks used to measure digital phalanx bone development using micro-CT could be used to measure bone development in digital photographs, and the association in pasture-based cows, between bone development, age and lameness history. METHODS:160 distal phalanges (from the hind feet of 40 cows) were collected post-mortem, photographed, and measured at four sites (A-D) near the flexor tuberosity. Associations between age and lameness history, and the average sum of A-D for the two lateral and two medial claws within a cow (BD-Ave) and the highest sum of A-D for an individual claw (BD-Max) were modelled. RESULTS:Median age of enrolled cows was 8 (min 3, max 12) years and 34/40 had a history of lameness in the lactation before culling. Only minor modifications to the measurement landmarks were needed to account for the differences between micro-CT scans and digital photographs. Age was associated with BD-Max and BD-Ave: a 1-year increase in age increased geometric mean BD-Max by 1.12 (95% CI = 1.03-1.21) times and geometric mean BD-Ave by 1.09 (95% CI = 1.04-1.14) times. Prior lameness was compatible with an increase and decrease in geometric mean BD-Max and BD-Ave. Compared to cows with no history of lameness in the previous lactation, for previously lame cows, BD-Max was 1.61 (95% CI = 0.88-2.95) and BD-Ave, 1.25 (95% CI = 0.89-1.78) times greater, equivalent to a 5- and 3-year age effect, respectively. Most of the measurement differences between claws were in D (abaxial caudal bone development), as 136/160 claws recorded zero for A, B and C but all claws had values > 0 mm for D. In all claws where only D was > 0 mm, bone development was smooth. In these claws, an additional year in age increased D measurements by 1.09 (95% CI = 1.05-1.11) times - similar to the effect on BD-Max, while the effect on the sum of the remaining measurements was compatible with both a moderate increase or decrease. These observations indicate the principal effect of age was on measurement D. CONCLUSIONS:Photography may provide an economical alternative to micro-CT for studying digital phalanx bone development in ex-vivo samples. Our data suggest lameness and age may affect bone development in pasture-based cows. However, these are preliminary data; further research is needed comparing CT and photography measurements, and to better understand the association between age, lameness and bone development in pasture-based dairy cows.
AIMS:To evaluate, in a sample of cows on a New Zealand dairy farm, whether different methods of oral supplementation with zinc were effective in raising serum Zn concentrations ≥ 18 μmol/L, the target threshold for protection from facial eczema. METHODS:From November to May, three different methods of oral supplementation of ZnSO4.7H2O were investigated for Friesian/Jersey cross cattle that had calved in July: (1) Individual daily dosing, where the amount of Zn added was based on individual estimated body weights; (2) small group dosing, where the amount of Zn added for the current day was based on the estimated mean bodyweight and the water consumption of the group the previous day; and (3) large group dosing, where the amount of Zn added was based on the estimated mean bodyweight and administered via a dosing pump attached to the drinking troughs' water supply. For this scenario, the herd's ZnSO4.7H2O requirement was calculated at 17 kg ZnSO4.7H2O/day. For Weeks 0-1, 8.5 kg ZnSO4.7H2O was added, with the full dose at Week 2, and continuing for the rest of the facial eczema season (approximately 16 weeks). Semi-quantitative analysis of the water consumption of the group over the previous day(s), plus subjective impressions of the effect of the current weather on the cows' drinking behaviour, were used to adjust the quantity of Zn mixed with the current day's water supply. For all scenarios, serum samples were taken periodically from study cows to monitor the serum Zn concentrations. RESULTS:Daily drenching increased serum Zn concentration: 12/15 cows (80%; 95% CI = 55-93%) reaching ≥ 18 μmol/L on Days 3 and 6. Under trough dosing, the half dose achieved a mean serum Zn concentration of 20.7 μmol/L and up to 60% (95% CI = 26-82%) of cows ≥ 18 μmol/L: at full dose the mean concentration was 16.3 μmol/L with 30% of cows (95% CI = 7-65%) ≥ 18 μmol/L. Supplementation using the dosing pump did not increase mean serum Zn concentration to ≥ 18 μmol/L at any timepoint (maximum proportion of cows ≥ 18 μmol/L: 44%). CONCLUSIONS AND CLINICAL RELEVANCE:Apart from individual dosing, Zn supplementation via drinking water did not reliably increase serum Zn concentrations. This is probably related to the great variability in both group and individual water consumption. Water-based Zn supplementation should not be recommended to prevent facial eczema.
AIMS:To determine the bacterial contamination rate of communal mobile handheld devices (MHD) used in a small animal referral hospital before and after cleaning with commercially available antibacterial wipes, and then after 24 hours of use. METHODS:All 18 communal MHD at a small animal emergency referral hospital were swabbed following a standardised protocol at three time points: before cleaning (swab 1), immediately after cleaning (swab 2), and after 24 hours of hospital-wide use (swab 3) to assess re-contamination rates. All swabs were sent to an external commercial laboratory for aerobic bacterial culture and species identification, including methicillin-resistant Staphylococcus aureus (MRSA) and S. pseudintermedius (MRSP). Results were reported as the presence or absence of the organisms isolated but not quantified. Differences in rates of bacterial contamination before and after cleaning were assessed using Cochran's Q test and Fisher's exact test. RESULTS:Swabs at swab session 1 showed 16/18 (88.9 (95% CI = 67.2-96.9)%) MHD to be contaminated: 6/18 (33.3 (95% CI = 10.9-55.7)%) with coliform bacteria, 5/18 (22.8 (95% CI = 6.5-49.1)%) with Bacillus spp. and 5/18 (22.8 (95% CI = 6.5-49.1)%) with coagulase-negative staphylococci (CNS). No MRSA or MRSP were identified. Immediately after cleaning, contamination was found on 1/18 (5.6 (95% CI = 0-16.5)%) devices. After 24 hours, 12/18 (66.7 (95% CI = 43.7-83.7)%) devices were contaminated, with coliform bacteria on 11/18 (61.1 (95% CI = 37.9-84.3)%) and CNS on 1/18 (5.6 (95% CI 0-16.4)%); no Bacillus spp. were identified. Significant differences in contamination rates were observed across the three time points (p < 0.001). The recontamination rate was 68.8%, with a rebound rate of 70.6% among culture-negative MHD. CONCLUSIONS:Communal MHD in this study were frequently contaminated, particularly with coliforms. Cleaning was associated with a marked, short-term reduction in detectable bacteria, but re-contamination rates following 24 hours of normal use were high. CLINICAL RELEVANCE:The high colonisation rate of bacteria on MHD suggests that regular cleaning protocols are required to minimise potential bacterial spread to personnel and patients, particularly given the high rate of re-contamination 24 hours after cleaning. Further studies are required to ascertain whether the source of contamination was human or animal, and whether it leads to transmission of disease and constitutes a health risk to patients.
AIMS:To characterise practice managers' perspectives on the interplay between worker well-being and organisational health in veterinary and human healthcare contexts. METHODS:Using a convergent mixed-methods design, we analysed data from 38 Australian practice managers who completed an anonymous online survey. Participants accessed the survey via links distributed using social media and email. The survey included the General Practice-Organisational Health (GP-OH) measure, along with items on professional duties, perceptions of worker well-being, current and desired supports, and perceived interactions between the two domains of interest. Quantitative analyses were exploratory and descriptive; qualitative responses were characterised using a conventional approach to content analysis. RESULTS:Practice managers described responsibilities spanning five domains of managing a health clinic: resources, operations, leadership, strategy, and governance. They typically rated staff well-being as "neutral/normal" or "high/good," based on observations of workers' health and welfare, team and culture, formal feedback, and employee performance. Ratings of organisational health were similarly favourable, with mean scores above the mid-point of the GP-OH scale. Ratings of staff well-being were positively correlated with GP-OH scores (ρ = 0.59; p < 0.01). Practice managers described a mutually reinforcing relationship between worker well-being and organisational health, centred on team morale, workforce stability, clinical performance, operational efficiency, and financial outcomes. Current organisational strategies to support well-being were primarily reactive and policy-driven, but participants desired more holistic, proactive approaches. Themes were largely consistent across the two health sectors, with some small differences. CONCLUSIONS:Findings were generally consistent with existing models of organisational health and employee well-being, while suggesting important contextual adaptations, particularly to settings outside the USA. Parallels in accounts from veterinary and human health practice managers suggest that organisational and managerial demands are often shared across these settings, with minor variations potentially arising from structural differences between the two sectors. CLINICAL RELEVANCE:Practice managers are key drivers of organisational and employee welfare, and future efforts to strengthen veterinary workplaces will benefit from engaging them as partners in design and implementation. Interventions to improve professional well-being in veterinary and human healthcare may be most effective when they emphasise social connection, systemic reform, and regular staff check-ins.
