New Zealand veterinary journal最新文献

{"title":"Tetanus prophylaxis in horses: guidelines for New Zealand and Australia based on a critical appraisal of the evidence.","authors":"A L Lovett, C B Riley, V Chapman, B Bell, B Bishop, A Grierson, L J Johnstone, B W Sykes","doi":"10.1080/00480169.2024.2365283","DOIUrl":"10.1080/00480169.2024.2365283","url":null,"abstract":"<p><p>Horses are exquisitely sensitive to tetanus neurotoxin and are exposed to the risk of infection with <i>Clostridium tetani</i> throughout life. The vaccine against tetanus is highly effective at preventing disease, whereas tetanus in unvaccinated populations is associated with high mortality rates. Current guidelines in New Zealand and Australia for the available vaccine contain contradictions and limitations surrounding the optimal tetanus immunisation protocols for both adult horses and foals. This review critically evaluates the scientific literature on tetanus prophylaxis in horses within the context of equine practice and available products in New Zealand and Australia. The review was conducted by a panel of industry and specialist veterinarians to obtain agreement on nine equine tetanus prophylaxis guidelines for practising veterinarians. The primary protocol for tetanus toxoid (TT) immunisation consists of a three-dose series IM for all horses ≥ 6 months of age, and a four-dose series IM is proposed if commencing vaccination in foals between 3 and 6 months of age. Tetanus prophylaxis in foals < 3 months of age relies on passive immunity strategies. Following the completion of the primary protocol, a TT booster dose IM should be administered within 5 years, and every 5 years thereafter. When followed, these protocols should provide adequate protection against tetanus in horses. Additional tetanus prophylaxis guidelines are provided for veterinarians attending a horse experiencing a known \"risk event\" (e.g. wound, hoof abscess, surgery, umbilical infection). When a correctly vaccinated horse experiences a risk event, pre-existing immunity provides protection against tetanus. When an unvaccinated horse or one with unknown vaccination status, or a foal born to an unvaccinated dam, experiences a risk event, TT IM and tetanus antitoxin (TAT) 1,500 IU SC should be administered simultaneously at separate sites, and the TT primary immunisation protocol should subsequently be completed for the horse's respective age. In previously immunised pregnant broodmares, a TT booster dose administered 4-8 weeks prior to parturition optimises the transfer of passive immunity against tetanus to the newborn foal via colostrum; provided that post-natal IgG concentration in serum is > 800 mg/dL (8 g/L), such foals should be passively protected against tetanus up to 6 months of age. Survivors of clinical tetanus must still receive the primary protocol for vaccination against tetanus. In summary, all horses in New Zealand and Australia should be vaccinated against tetanus with protection maintained throughout life via TT booster doses, facilitated by accurate medical record keeping and client education.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"241-255"},"PeriodicalIF":1.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141443149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction.","authors":"","doi":"10.1080/00480169.2024.2362959","DOIUrl":"10.1080/00480169.2024.2362959","url":null,"abstract":"","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"iii"},"PeriodicalIF":1.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141238298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of recovery of sheep, goats, and calves from reversible electrical head-only and head-to-body stunning for halal meat production.","authors":"N J Beausoleil, M M Farouk, J Webster, C B Johnson, S Dowling, A Q Sazili, C Cameron","doi":"10.1080/00480169.2024.2367532","DOIUrl":"10.1080/00480169.2024.2367532","url":null,"abstract":"<p><strong>Aims: </strong>To compare the recovery of lambs, goats, and calves from head-only (HO) or high-frequency head-to-body stunning and evaluate the complementary use of behaviour and electroencephalography (EEG) to assess return to consciousness after electrical stunning in these species.</p><p><strong>Methods: </strong>Six-month-old lambs, adult goats and calves (< 7 days old) were subjected to reversible head-only stunning (50 Hz, 1 A, 2 seconds) or reversible high-frequency head-to-body stunning (RHTB: HO followed by 2,000 Hz, 2 A, 4-second stun to body). Following stunning, behavioural recovery was assessed in 21 lambs, 22 goats, and 20 calves. Latencies to first perform behaviours (end of convulsions, head lift, attempt to right, successful righting, attempt to stand, successful standing) after stunning were scored from video recordings. Recovery of electrical brain activity indicative of consciousness was assessed using EEG in a separate cohort of minimally-anaesthetised lambs, goats and calves (n = 20 per species). EEG traces collected before and after stunning were classified as normal, epileptiform, isoelectric, or transitional activity. Following stunning, the duration of epileptiform and isoelectric activity combined (states of brain activity incompatible with conscious awareness) was calculated, as was latency to return of normal (pre-stun) EEG.</p><p><strong>Results: </strong>The RHTB stun was reversible in all three species, although one sheep failed to recover and was euthanised. Both methods caused tonic and clonic convulsions in all species. Behavioural recovery of sheep and calves was similar for both methods while goats took longer to recover from RHTB than HO stunning. There was no evidence of differences between methods in the duration of EEG incompatible with consciousness or the latency to recovery of normal EEG.</p><p><strong>Conclusions: </strong>Head-to-body stunning as applied here produced a reversible electrical stun in lambs, adult goats and young calves, although the benefits in terms of meat quality and operator safety are uncertain. Goats took longer to recover behaviourally from head-to-body stunning, possibly due to disrupted motor function, but there was no indication that post-stun unconsciousness lasted longer than following head-only stunning in any species. The normal behaviour for the animals' developmental age should be considered when deciding on behavioural indicators of recovery. The minimal anaesthesia model provided excellent quality EEG data that was valuable for interpretation of the behavioural responses.</p><p><strong>Clinical relevance: </strong>For the purposes of pre-slaughter stunning of sheep, goats and young calves, recovery appears comparable between the two methods, with all but 1/63 animals in the behaviour study recovering normal function.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"288-299"},"PeriodicalIF":1.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141469759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding psychological outcomes following exposure to potentially morally injurious events in animal care: development of the Moral Distress-Posttraumatic Growth Scale for Veterinary Professionals.","authors":"C E Connolly, K Norris","doi":"10.1080/00480169.2024.2342903","DOIUrl":"10.1080/00480169.2024.2342903","url":null,"abstract":"<p><strong>Aims: </strong>To generate a taxonomy of potentially morally injurious events (PMIE) encountered in veterinary care and develop an instrument to measure moral distress and posttraumatic growth following exposure to PMIE in the veterinary population.</p><p><strong>Methods: </strong>Development and preliminary evaluation of the Moral Distress-Posttraumatic Growth Scale for Veterinary Professionals (MD-PTG-VP) employed data from veterinary professionals (veterinarians, veterinary nurses, veterinary technicians) from Australia and New Zealand across three phases: (1) item generation, (2) content validation, and (3) construct validation. In Phase 1 respondents (n = 46) were asked whether they had experienced any of six PMIE and to identify any PMIE not listed that they had experienced. In Phase 2 a different group of respondents (n = 11) assessed a list of 10 PMIE for relevance, clarity and appropriateness. In Phase 3 the final instrument was tested with a third group of respondents (n = 104) who also completed the Short Post-Traumatic Stress Disorder Rating Interview (SPRINT), a measure of posttraumatic stress, and the Stress-Related Growth Scale-Short Form (SRGS-SF) a measure of perceived posttraumatic growth. Spearman's correlation coefficients were calculated between respondent scores on each of the MD-PTG-VP subscales, the SPRINT, and the SRGS-SF to assess construct validity.</p><p><strong>Results: </strong>A 10-item taxonomy of PMIE encountered in veterinary care was generated in Phase 1. Items were deemed relevant, clear and appropriate by veterinary professionals in Phase 2. These were included in the developed instrument which measures frequency and impact of exposure to 10 PMIE, yielding three subscale scores (exposure frequency, moral distress, and posttraumatic growth). Assessment of construct validity by measuring correlation with SPRINT and SRGS-SF indicated satisfactory validity.</p><p><strong>Conclusions: </strong>The MD-PTG-VP provides an informative tool that can be employed to examine professionals' mental health and wellbeing following exposure to PMIE frequently encountered in animal care. Further evaluation is required to ascertain population norms and confirm score cut-offs that reflect clinical presentation.</p><p><strong>Clinical relevance: </strong>Once fully validated this instrument may be useful to quantify the frequency and intensity of positive and negative aspects of PMIE exposure on veterinary professionals so that accurate population comparisons can be made and changes measured over time.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"201-211"},"PeriodicalIF":1.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140870017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction.","authors":"","doi":"10.1080/00480169.2024.2349344","DOIUrl":"10.1080/00480169.2024.2349344","url":null,"abstract":"","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"iii"},"PeriodicalIF":1.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140874753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An observational study of farmer-reported clinical mastitis in New Zealand dairy ewes.","authors":"G Chambers, R Laven, A Grinberg, A Ridler, N Velathanthiri","doi":"10.1080/00480169.2024.2344566","DOIUrl":"10.1080/00480169.2024.2344566","url":null,"abstract":"<p><strong>Aims: </strong>To describe the incidence, aetiology, treatment, and outcomes of farmer-reported clinical mastitis on New Zealand dairy sheep farms.</p><p><strong>Methods: </strong>A prospective cohort study was conducted on 20 spring-lambing New Zealand sheep milking farms over the 2022-2023 season. Clinical mastitis was defined as a change in the appearance of milk and/or signs of inflammation in the gland. Farmers were required to report all cases of clinical mastitis and collect information on affected ewes' demographics, clinical features, treatments (where applicable), and outcomes. Milk samples from mastitic glands were submitted for microbiological culture and identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF).</p><p><strong>Results: </strong>Partial or complete clinical mastitis data were available for 236 cases from 221 ewes on 18/20 study farms. Clinical mastitis was diagnosed in 0-6% of ewes at the farm level, with an overall incidence of 1.8 (95% CI = 1.0-3.2)% using the study data, or 2.3 (95% CI = 1.6-3.3)% using the study data and farmer estimates that included unreported cases. Cases occurred mostly in early lactation, with 59% detected during the lambing period (August-October), at a median of 7 (IQR 3, 40) days in milk. The majority of cases featured clots in the milk (59%), swelling (55%), and unevenness (71%) of the glands. Pyrexia (rectal temperature <math><mo>≥</mo></math> 40.0°C) was diagnosed in 25% of cases and depression (lethargy, inappetence, or inability to stand) in 26% of cases. Treatment was given to 46% of cases, with tylosin being the most commonly used treatment (50% of treated cases). The most common outcome was immediate drying off to be culled without treatment (32%), followed by still milking and recovered but with lasting problems (25%). Nearly half of all the milk samples submitted were culture negative. <i>Streptococcus uberis</i> (14%), non-aureus staphylococci (12%), and <i>Staphylococcus aureus</i> (11%) were the most common isolates, found on 12, 8 and 8 of the 16 farms with microbiological data, respectively.</p><p><strong>Conclusions: </strong>Clinical mastitis affected up to 6% of ewes at the farm level. Systemic signs were observed in one quarter of affected ewes, suggesting a role for supportive treatment. Clinical mastitis can be severe and challenging to fully resolve in New Zealand dairy sheep.</p><p><strong>Clinical relevance: </strong>This is the first systematic study of clinical mastitis in New Zealand dairy ewes. It provides baseline information specific to New Zealand conditions for farmers, veterinarians, and other advisors to guide the management of mastitis for the relatively new dairy sheep industry in New Zealand.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"212-224"},"PeriodicalIF":1.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140892324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ulcerative stomatitis associated with yellow bristle grass in New Zealand dairy cows.","authors":"J P O'Connell, K E Lawrence, D Aberdein, C Gans, D Schluter, H Taylor","doi":"10.1080/00480169.2024.2342910","DOIUrl":"10.1080/00480169.2024.2342910","url":null,"abstract":"<p><strong>Case history: </strong>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 (<i>Setaria pumila</i>).</p><p><strong>Clinical findings: </strong>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.</p><p><strong>Diagnosis: </strong>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.</p><p><strong>Clinical relevance: </strong>Clinicians should be aware of the potential for hay or baleage contaminated with yellow bristle grass to cause oral lesions in cattle.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"236-240"},"PeriodicalIF":1.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140857660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics and challenges of companion animal rescue organisations in New Zealand.","authors":"C Roseveare, M C Gates","doi":"10.1080/00480169.2024.2344560","DOIUrl":"10.1080/00480169.2024.2344560","url":null,"abstract":"<p><strong>Aims: </strong>To describe the characteristics of companion animal rescue organisations (CARO) in New Zealand; to describe current capacity, resource limitations and challenges of CARO with a particular focus on cats and dogs; and to explore support for creating a national database of CARO in New Zealand.</p><p><strong>Methods: </strong>A cross-sectional survey was administered to CARO in New Zealand in May 2022. The survey asked about organisational characteristics, types and numbers of animals cared for, services provided, policies, staffing, funding sources, challenges, and attitudes towards a national database for rescue organisations. Descriptive statistics were provided for all quantitative study variables and free-text comments were analysed for common themes.</p><p><strong>Results: </strong>The survey was completed by 106/208 (51%) known CARO distributed across the country. These CARO provided services to an estimated 59,874 homeless animals annually with 86/106 (81%) providing services to cats and/or dogs. Primary services provided by CARO who cared for cats or dogs included rehoming (72/86; 84%) and housing (70/86; 81%) animals. Intake was managed through a combination of strategies. Donations (72/86; 82%) were the main funding source. The 62 registered charities were more likely to report being funded by grants than the 23 non-charities (39/62 (63%) <i>vs</i>. 1/23 (4%); p < 0.001), and non-charities were more likely to self-fund (18/23 (78%) <i>vs.</i> 20/62 (32%); p < 0.001). Nearly half of the CARO that provided workforce information (35/72; 49%) had a workforce of 10 or fewer including volunteers. A total of 5,699 people worked for 86 CARO that care for cats or dogs of whom 4,847 (85%) were part-time volunteers. Of the 72 cat and dog CARO who provided workforce information, 57/72 (79%) relied solely on volunteers.The majority of all 106 CARO respondents (78/106; 73%) indicated they were likely to register on a national database of CARO, subject to addressing concerns about time required and information security.CARO respondents described challenges of insufficient funding, access to veterinary services, and a shortage of volunteers and foster homes, with additional concerns including a lack of public awareness, supportive legislation, and resources. Financial support (90/106; 85%) and policy change (76/106; 72%) were preferred support options.</p><p><strong>Conclusions: </strong>This study highlights the significant role played by CARO in New Zealand and the challenges they face, emphasising the need for financial support, legislation, and initiatives extending beyond the rescue sector to reduce the number of animals being surrendered. The findings also suggest a willingness among CARO to participate in a national database.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"225-235"},"PeriodicalIF":1.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140892282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Farm-level risk factors and treatment protocols for lameness in New Zealand dairy cattle.","authors":"W A Mason, K R Müller, L J Laven, J N Huxley, R A Laven","doi":"10.1080/00480169.2024.2345257","DOIUrl":"10.1080/00480169.2024.2345257","url":null,"abstract":"<p><strong>Aims: </strong>To identify farm-level risk factors for dairy cow lameness, and to describe lameness treatment protocols used on New Zealand dairy farms.</p><p><strong>Methods: </strong>One hundred and nineteen farms from eight veterinary clinics within the major dairying regions of New Zealand were randomly enrolled into a cross-sectional lameness prevalence study. Each farmer completed a questionnaire on lameness risk factors and lameness treatment and management. Trained observers lameness scored cattle on two occasions, between October-December (spring, coinciding with peak lactation for most farms) and between January-March (summer, late lactation for most farms). A four-point (0-3) scoring system was used to assess lameness, with animals with a lameness score (LS) ≥2 defined as lame. At each visit, all lactating animals were scored including animals that had previously been identified lame by the farmer. Associations between the farmer-reported risk factors and lameness were determined using mixed logistic regression models in a Bayesian framework, with farm and score event as random effects.</p><p><strong>Results: </strong>A lameness prevalence of 3.5% (2,113/59,631) was reported at the first LS event, and 3.3% (1,861/55,929) at the second LS event. There was a median prevalence of 2.8% (min 0, max 17.0%) from the 119 farms. Most farmers (90/117; 77%) relied on informal identification by farm staff to identify lame animals. On 65% (75/116) of farms, there was no external provider of lame cow treatments, with the farmer carrying out all lame cow treatments. Most farmers had no formal training (69/112; 62%). Animals from farms that used concrete stand-off pads during periods of inclement weather had 1.45 times the odds of lameness compared to animals on farms that did not use concrete stand-off pads (95% equal-tailed credible interval 1.07-1.88). Animals from farms that reported peak lameness incidence from January to June or all year-round, had 0.64 times odds of lameness compared to animals from farms that reported peak lameness incidence from July to December (95% equal-tailed credible interval 0.47-0.88).</p><p><strong>Conclusions: </strong>Lameness prevalence was low amongst the enrolled farms. Use of concrete stand-off pads and timing of peak lameness incidence were associated with odds of lameness.</p><p><strong>Clinical relevance: </strong>Veterinarians should be encouraging farmers to have formal lameness identification protocols and lameness management plans in place. There is ample opportunity to provide training to farmers for lame cow treatment. Management of cows on stand-off pads should consider the likely impact on lameness.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"171-182"},"PeriodicalIF":1.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140892355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concurrent use of two dual-combination drenches containing monepantel/abamectin and oxfendazole/levamisole in sheep: effect on marker residues 21 and 28 days after administration.","authors":"C H McKay, K E Baker, K J VanHoff, C Smith, S D George","doi":"10.1080/00480169.2024.2314494","DOIUrl":"10.1080/00480169.2024.2314494","url":null,"abstract":"<p><strong>Aims: </strong>To determine the concentration, in comparison with the maximum residue limit (MRL), of anthelmintic marker residues in the target tissues (liver and fat) of sheep treated concurrently with two oral drenches, one containing monepantel and abamectin and the other oxfendazole and levamisole.</p><p><strong>Methods: </strong>On day 0 of the study, 12 sheep (six male and six female; 8-9-months old) were dosed according to individual body weight determined the day prior. Zolvix Plus (dual-active oral drench containing 25 g/L monepantel and 2 g/L abamectin) was administered to all animals prior to administration of Scanda (dual-active oral drench containing 80 g/L levamisole hydrochloride and 45.3 g/L oxfendazole). Six sheep (three male and three female) were slaughtered 21 and 28 days after treatment and renal fat and liver samples were collected.Using validated methods, analyses for monepantel sulfone, abamectin, levamisole and oxfendazole (expressed as total fenbendazole sulfone following conversion of the combined concentrations of oxfendazole, fenbendazole and fenbendazole sulfone) were performed on liver samples while renal fat specimens were analysed for monepantel sulfone and abamectin residues only. Detected concentrations were compared to the established MRL in sheep for each analyte determined by the Ministry for Primary Industries.</p><p><strong>Results: </strong>All residues detected in samples of liver and fat collected 21 and 28 days after treatment were below the MRL for each analyte. All liver samples collected on day 21 had detectable monepantel sulfone (mean 232 (min 110, max 388) μg/kg) and oxfendazole (mean 98.7 (min 51.3, max 165) μg/kg) residues below the MRL (5,000 and 500 μg/kg, respectively). Monepantel sulfone (mean 644 (min 242, max 1,119) μg/kg; MRL 7,000 μg/kg) residues were detected in 6/6 renal fat samples. Levamisole residues were detected in 3/6 livers (mean 40.0 (min 14.3, max 78.3) μg/kg; MRL 100 μg/kg), and abamectin residues in 1/6 livers (0.795 μg/kg; MRL 25 μg/kg) and 2/6 fat samples, (mean 0.987 (min 0.514, max 1.46) μg/kg; MRL 50 μg/kg) 21 days after treatment.</p><p><strong>Conclusion and clinical relevance: </strong>These results suggest that concurrent administration of Zolvix Plus and Scanda to sheep is unlikely to result in an extended residue profile for any of the active ingredients, with all analytes measured being under the approved New Zealand MRL 21 days after treatment. This work was not completed in line with guidance for establishing official residue profiles, nor is it sufficient to propose a new withholding period.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":" ","pages":"133-140"},"PeriodicalIF":1.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139900292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}