New Zealand veterinary journal最新文献

Aims: To collate information on the analgesic drugs used in native bird species by wildlife facilities in Aotearoa New Zealand and to explore the rationale for the choice of dose used.

Methods: A survey was conducted to collect information regarding analgesic type and dosing in New Zealand native birds. The survey was emailed to 26 wildlife centres in New Zealand and responses were received between April and August 2021. Respondents were invited to participate in an interview after completing the survey to elaborate on their responses.

Results: Survey responses were received from 11 facilities, and four follow-up interviews were conducted. The 11 facilities treated 42 different species of native birds. The most frequently reported analgesic used for the treatment of native birds was meloxicam, but butorphanol, buprenorphine and gabapentin were also reported to be commonly used. A variety of responses were received about the method used to determine the analgesic dose. Administration of analgesia to birds in these facilities was via IM, IV or SC injection, orally, or topically. Of the four respondents who answered the question, 75% believed there to be insufficient information widely available on the safe and effective doses for analgesia for birds.

Conclusions and clinical relevance: Meloxicam, butorphanol and tramadol were most frequently reported as commonly used analgesic drugs for avian species endemic to NZ. We highlight the need for further research on the dose requirements for analgesic drugs in New Zealand native birds to provide optimal care to this group of patients.

Case history: A seasonal syndrome, presenting as corneal oedema and distinct from infectious keratoconjunctivitis, has been reported in sheep, goats, and camelids in New Zealand. This study details the diagnostic investigation on two properties, of multiple cases of corneal oedema in small ruminants. Outbreak 1 occurred in a mob of sheep in April/May 2023 in the Manawatū region, with 27/52 sheep affected. Outbreak 2 occurred in a group of farmed goats in February/March 2024 in the Auckland region, with 4/5 goats affected.

Clinical findings: A spectrum of corneal abnormalities, including focal and diffuse corneal oedema and bullous keratopathy/corneal hydrops, were observed in both the sheep and goats. All animals had normal menace responses and pupillary light reflexes, and there was no associated blepharospasm, epiphora or ocular discharge, except in five sheep that developed secondary ulcerative keratitis. These five sheep had severe ulceration or corneal perforation necessitating euthanasia, while the other affected sheep all recovered within 5 months. The corneal oedema in all goats improved over the following 6 months, but one required a thermokeratoplasty procedure to aid resolution of the oedema and the other three goats had residual focal oedema that did not appreciably affect vision.

Diagnosis: It is proposed that a primary corneal endothelial dysfunction was the cause of the oedema, but the aetiopathogenesis is not well understood.

Clinical relevance: This is the first peer-reviewed description of this presentation in New Zealand. In contrast to other causes of corneal oedema in ruminants, seasonal corneal oedema is, in some cases, self-limiting with minimal impacts on production and welfare. However, secondary ulceration and corneal perforation may occur, which is painful and may lead to deep infections and permanent visual deficits. Topical antibiotic therapy does not appear to aid in the resolution of the oedema.

Abbreviations: MPI: Ministry for Primary Industries.

Aims: To investigate the genotypes of Chlamydia psittaci in birds associated with two clusters of disease from a zoological collection in New Zealand.

Materials and methods: Samples were collected over two time periods from birds resident at Auckland Zoo (Auckland, NZ). In 2016, two little penguins/kororā (Eudyptula minor) showed respiratory disease on admission to the zoo hospital. Post-mortem samples of liver and lung were collected from the penguins and from 10 other birds from the zoo's collection that died without clinical signs. Further, 128 conjunctival, choanal and cloacal swabs were collected from 27 different bird species, all housed within the zoo and without clinical signs.In 2019, a cluster of deaths of four diamond doves (Geopelia cuneata) and two superb parrots (Polytelis swainsonii) occurred in one mixed-species aviary. Twenty post-mortem samples were collected from these birds and other birds that died around the same time across the zoo. DNA was extracted from all samples and initially tested for C. psittaci using a high-resolution melting quantitative PCR (HRM qPCR) protocol. We applied multi-locus sequence typing (MLST) on 10 C. psittaci-positive samples from four different avian species, including one sample from 2016 (little penguin) and nine post-mortem samples from 2019.

Results: C. psittaci was detected in 14/140 (0.10; 95% CI = 0.061-0.161) of the samples from 2016 from seven species. A penguin sample was sequenced aligning with ompA genotype B and was later characterised by MLST as C. psittaci strain ST27. With the exception of the sample from the sick penguin, the positive results yielded very low DNA copy numbers in the HRM qPCR, potentially indicating latent infections. In the 2019 cluster, C. psittaci was detected in 9/20 post-mortem samples from three bird species (diamond dove, superb parrot, and zebra finch (Taeniopygia guttata)). All nine sample sequences aligned with ompA genotype B and were characterised by MLST as C. psittaci strain ST27.

Conclusions and clinical relevance: C. psittaci was present within the zoological collection in a variety of bird species associated with two disease clusters. Most of these infections were asymptomatic, but a cluster of deaths due to avian chlamydiosis in 2019 affecting three species of birds was due to a single genotype, ST27, that was also present in a wild penguin in 2016. This provides evidence of pathogenicity in birds for this genotype.

Abbreviations: C-C-C: Conjunctival, choanal slit and cloacal swabs; Cq: Cycle threshold; HRM qPCR: High resolution melting quantitative PCR; MLST: Multi-locus sequence typing; ompA: Outer membrane protein A; ST: Sequence type; WGS: Whole genome sequencing.

Aims: To assess the effectiveness of testing young calves using an ELISA for antibodies to Neospora caninum with adjusted cut-off values to account for the presence of maternal antibodies, as an aid in decision-making during calf-rearing, with the purpose of eradicating neosporosis from endemically infected dairy herds.Methods: Replacement heifer calves on two dairy farms with endemic neosporosis were blood sampled at approximately 1-4 weeks of age. Sera were tested with an ELISA for antibodies to N. caninum, with the thresholds increased (based on unpublished data) to account for colostrum intake. The sample/positive (S/P) cut-off value for seronegative animals was increased from the manufacturer's recommendation of S/P < 30 to < 70; the S/P value for seropositive was increased from ≥ 40 to ≥ 100; and S/P values 70-100 were considered inconclusive. Calves with inconclusive results were retested using standard thresholds at approximately 4 months of age (after colostral antibodies had waned). Seropositive calves were removed from the replacement herd. This protocol was first implemented in 2016. From 2018 onwards, parentage testing was carried out, and the calves' results were extrapolated to their dams. Dams of seropositive calves were bred predominantly to beef semen. The proportion of seronegative calves in each cohort from 2016 to 2023 was calculated, and the reproductive performance of seronegative replacement calves (% producing a calf at approximately 24 months of age) was analysed.Results: The proportion of seropositive replacement calves peaked in 2017 (19.5%) and by 2023 had reduced to 1.2%. The odds of a heifer being seronegative in 2023 compared to 2016 were 14.0 (95% CI = 4.12-87.56) times higher. Compared to 2014/2015 when replacement heifers' serostatus was unknown, after 2016 (the first year when replacement heifer serostatus was established) at least 12.9% more heifers produced a calf at approximately 24 months of age; compared to 2014 the odds were at least 2.88 (95% CI = 1.75-4.88) times higher.Conclusions and clinical relevance: Combining early testing of replacement heifers with the identification and breeding management of dams of seropositive replacement heifers reduced the proportion of seropositive heifer calves in subsequent years and improved the reproductive performance of heifer cohorts. Further research is required to establish optimal ELISA cut-off values, but this strategy is likely to be a useful tool to reduce the N. caninum seroprevalence in endemically infected dairy herds.Abbreviations: BVDV: Bovine viral diarrhoea virus; S/P: Sample/positive ratio.

Case history: Three dogs with adrenal masses scheduled for adrenalectomy were prospectively enrolled into a study to investigate the effectiveness of a 1:1-scale, three-dimensional (3D) printed model of neoplastic adrenal glands to aid surgical planning and provide intra-operative assistance during adrenalectomy in dogs.Case 1 presented with anorexia, lethargy and a distended abdomen; Case 2 with loss of appetite, behavioural changes, and vocalisation; and Case 3 with mild inappetence during the previous 15 days.Clinical and imaging findings: On physical examination, mild abdominal pain was noted in all cases. Case 1 was consistently mildly hypertensive over repeated measurements. All cases had mild or moderate elevations in the activities of alanine aminotransferase and aspartate aminotransferase, and the concentration of C-reactive protein. Cases 1 and 2 also had mild leucocytosis. Abdominal CT revealed a left-sided adrenal tumour with caval invasion in Case 1, and right-sided adrenal tumours without caval invasion in Cases 2 and 3. 3D-printed models were created from the CT scan. Different colours were assigned to anatomical structures for better visualisation. Measurements of six anatomical landmarks were made on CT images and on the 3D-printed model. The median absolute difference in measurements taken from the model and the CT scan was 0.75 (min 0, max 3.2) mm.Treatment and outcome: All dogs underwent surgical removal of the adrenal tumour via sterno-pubic celiotomy. Placing the 3D model on the operating table in the same orientation as the patient allowed for precise pre-planning of the dissection depth. Printed without the fat, and fibrous and capsular tissues that typically cover the retroperitoneal space, the model helped the surgeon to visualise vascular structures that were still covered by connective tissue in the patient. Subjectively, the use of 3D models improved surgical planning and execution by enhancing the understanding of anatomical relationships and enabling the accurate identification of surgical landmarks.No major intra-operative complications were reported. Post-operative outcomes were favourable, with no significant complications observed.Clinical relevance: The use of 3D-printed models in adrenal surgeries for dogs may enhance the surgeon's spatial awareness and intra-operative confidence. We recommend that these models are used in conjunction with CT imaging for effective pre-operative planning. Further research with larger sample sizes and a control group would allow a fuller exploration of the benefits of 3D-printed models in veterinary surgical practices.Abbreviations: ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; CRP: C-reactive protein; CVC: Caudal vena cava; 3D: Three-dimensional.

Aims: To estimate prevalence and incidence of intramammary infections (IMI) using herd test somatic cell counts (SCC) or quarter-level microbiology in a single pasture-based, seasonal calving dairy herd.

Methods: Over four seasons (2010/11-2013/14) milk samples were collected for microbiology from quarters of all cows at four times; calving, MID1 (mean 116 (SD 21) days in milk (DIM)), MID2 (mean 204 (SD 21) DIM), and at drying off (DO; mean 266 (SD 30) DIM). SCC was determined every 1-4 (median = 2) weeks. Quarters were defined as having a new IMI if a bacterium was isolated that was not present at the preceding milk sampling and a cow was defined as having a new IMI where one or more quarters had a new IMI. Cows were defined as having a new high SCC where SCC increased to ≥ 200,000 cells/mL. Binary logistic regression and Poisson models were used to estimate prevalence and incidence rate (IR) of new infections. Cow-level IR estimates from bacteriology and SCC were compared using χ² analyses, and the sensitivity and specificity were estimated for SCC to estimate IR, assuming bacteriology was the gold standard.

Results: The prevalence of cows with a high SCC was 12.7 (95% CI = 12.3-13.1)% and quarter-level prevalence of IMI was 10.7 (95% CI = 10.2-11.1)%. The unadjusted IR for a new cow-level high SCC was 2.2 (95% CI = 2.0-2.4)/1,000 cow-days and for a new quarter-level IMI was 0.82 (95% CI = 0.71-0.95)/1,000 quarter-days at risk. Prevalence and IR were associated with DIM (p < 0.001), age (p < 0.001), and season (p < 0.001). The agreement between the IR based on herd test SCC and microbiology at cow-level was 77.1% (p < 0.001), with the level of agreement highest in mid-lactation. The sensitivity and specificity of an increase in SCC were 29.8% and 88.9%, respectively.

Conclusions: Prevalence and IR varied by season, age and DIM. While the IR estimates differed between estimates based on a high SCC at the cow-level, and quarter-level microbiology, the level of agreement was 77% suggesting utility of cow-composite SCC data as a mastitis monitoring tool. However, the sensitivity of incidence based on elevated SCC was only approximately 30% relative to quarter-level microbiology as the gold standard.

Clinical relevance: This study provides the first estimates of prevalence and incidence of IMI in pasture-based dairy cows.Abbreviations: DIM: Days in milk; DO: Dry Off; EMM: Estimated marginal mean; IMI: Intramammary infection; IR: Incidence rate; NAS: Non-aureus staphylococci; SCC: Somatic cell count; TAR: Time at risk.

Case history: Two dogs, a 10-year-old male Siberian Husky cross and an 11-year-old male Cocker Spaniel were referred to a specialist veterinary hospital in Melbourne, Australia, for treatment of metastatic anal sac apocrine gland adenocarcinoma (ASAGAC) and concurrent hypercalcaemia (concentration of ionised calcium in serum > 1.5 mmol/L) of malignancy.

Clinical findings: Case 1 had a left anal sac mass approximately 5.5 cm in diameter, enlarged sub-lumbar lymph nodes palpable on rectal examination and a concentration of ionised calcium in serum of 2.45 (reference range 1.2-1.32) mmol/L. Soft tissue opacities suspicious for metastatic pulmonary nodules were observed on thoracic radiographs. CT of Case 2 revealed bilateral anal gland masses (left: 4.7 × 3.2 cm; right: 2.8 × 2.1 cm) and a large, ill-defined, intrapelvic mass (7.0 × 6.0 cm) encompassing the medial iliac and internal iliac lymph nodes and intimately associated with the aortic blood vessels. Cytology of fine-needle aspirates of the anal gland masses of both dogs was consistent with ASAGAC. The owners of both dogs declined surgical intervention and medical management with toceranib phosphate was initiated in the gross disease setting.

Treatment and outcome: Toceranib was initially administered at a dose of 2.5 mg/kg orally every other day in both dogs. Due to side effects from this medication, including hypocalcaemia, the dosing schedule was adjusted to Monday, Wednesday, and Friday with a dose range of 2.25-2.5 mg/kg. Both dogs remained alive, Case 1 after 519 days and Case 2 after 477 days, and were normocalcaemic at the time of writing. Both dogs experienced resolution of hypercalcaemia of malignancy while being treated with toceranib alone: hypercalcaemia was controlled for a total of 12 months in Case 1 and 15 months in Case 2. During treatment the anal sac mass of Case 1 remained approximately 5 cm in diameter and the sub-lumbar lymph node remained subjectively stable though no objective measurements were taken. Case 2's anal sac masses and intrapelvic lymph node mass subjectively reduced in size based on palpation.

Clinical relevance: This case series highlights two instances where toceranib monotherapy effectively managed hypercalcaemia of malignancy secondary to metastatic ASAGAC. Despite the presence of extensive macroscopic neoplastic disease, both dogs achieved durable control of hypercalcaemia with toceranib treatment.Abbreviations: ASAGAC: Anal sac apocrine gland adenocarcinoma; cRECIST: Canine response evaluation criteria in solid tumours; HHM: Humoral hypercalcaemia of malignancy; OST: Overall survival time; PFS: Progression-free survival; PTH: Parathyroid hormone; PTHrP: Parathyroid-related hormone peptide; RTK: Receptor tyrosine kinase; TKI: Tyrosine kinase inhibitor.

Case history: Between June 2017 and April 2019, three captive tuatara from a zoological facility in the South Island of New Zealand were found unwell and admitted to veterinary care. One other tuatara from the same facility was found dead from misadventure in May 2019.

Clinical findings: All three unwell tuatara showed clinical signs of lethargy, mucous membrane pallor, and dehydration, with haematoma formation/swelling in dependent parts of the body. Fine needle aspiration and cytology of the swellings showed common features of peripheral blood, with variable other cytological findings. Haematology confirmed marked anaemia in Case 1 (PCV 5%; reference range 22-53%) and Case 2 (PCV 1%) and suspected mild anaemia in Case 3 (PCV 27%). Case 1 died 6 weeks after initial presentation, whereas Cases 2 and 3 died soon after presentation.

Pathological findings: Post-mortem examination showed general pallor of soft tissues in the three tuatara with clinical signs of coagulopathy. There was haemorrhage in the bladder wall of Case 1, while Cases 2 and 3 had haematomas (subcutaneous in Case 2 and peri-oesophageal in Case 3). The pathological diagnosis in Case 4 was death by asphyxiation following burrow collapse. Retrospective analysis showed brodifacoum was present in liver tissue at a concentration of 0.26 mg/kg in Case 3, and in skeletal muscle tissue at concentrations of 0.019 mg/kg in Case 2 and 0.035 mg/kg in the non-clinical case (Case 4).

Diagnosis: The clinical signs and post-mortem findings were consistent with anticoagulant poisoning in three tuatara, and tissue concentrations of brodifacoum demonstrated exposure in three animals, including one animal with no clinical signs of coagulopathy (Case 4). Definitive diagnosis was prevented, however, by inconsistent toxicology testing and a limited understanding of toxicity thresholds in reptiles in general, and tuatara specifically.

Clinical relevance: This case series suggests that tuatara are susceptible to anticoagulant poisoning and this has implications for both the captive management of tuatara, and also the use of rodenticides in tuatara habitat, such as offshore islands and mainland sanctuaries.

Abbreviations: AR: Anticoagulant rodenticide; LD50: Median lethal dose; SGAR: Second generation anticoagulant rodenticide.

Current paradigms and practices impede the ability of practitioners to fully utilise clinical pathology results from blood and other body fluids to recognise and manage disease in veterinary patients. These issues include analyser bias, the suitability of population reference intervals, and "grey areas" around individual results. Analyser bias gives rise to different results for the same sample determined on different analysers (even of the same model at commercial laboratories). Such bias is often not accurately accounted for by using reference intervals specific for the different analysers. The ideal solution would be harmonising analysers so that results are equivalent regardless of the analyser they were determined on. Without harmonisation, results from different analysers should not be compared. Population-based reference intervals may not reflect the local population and, for most analytes, are much wider than an individual patient's normal fluctuation of results. This means that clinically relevant changes that remain within the population reference interval may be missed. Rather than assessing results in relation to a patient's cohort, results can be assessed in relation to a patient's prior results, expected analyser variation and expected physiological fluctuation. Such fluctuations are known as biological variation. Biological variation enables individualised reference intervals to be determined from prior results obtained when a patient is clinically stable. Such reference intervals are not yet readily available; however, assessing prior results and comparing them to expected variation (see Supplementary Tables 1 and 2) to recognise the significance of any change could be used as an interim measure. A single laboratory result represents a range of possible values. This range is known as dispersion and is also determined from biological and analyser variation. Dispersion creates grey areas around individual results and thresholds such as reference interval limits and staging of disease. Therefore, any threshold should not be taken as definitive and apparent changes may be within expected physiological fluctuation and therefore not significant.This review assesses the background and science behind these issues and offers ideal solutions for how they may be addressed in the future and practical approaches that can be immediately incorporated by clinicians into daily practice. Addressing these issues can help improve clinical pathology acuity and thus improve outcomes for veterinary patients.Abbreviations: CKD: Chronic kidney disease; CV_A: Analyser variation; CV_G: Inter-individual (group) variation; CV_I: Intra-individual variation; HSP: Homeostatic set point; IRIS: International Renal Interest Society; RCV: Reference change value; SDMA: Symmetric dimethylarginine.