Use of equine chorionic gonadotropin in lactating dairy cattle: a rapid review.

AIMS: To use an evidence-based approach to evaluate the available research data on the efficacy of equine chorionic gonadotropin (eCG) to improve reproductive performance of dairy cows when added to oestrus synchronisation programmes for the treatment of cows not detected in oestrus. METHODS: A rapid literature review was conducted to summarise the existing trial data, primarily the effect of eCG on conception rate (CR) to fixed time artificial insemination (FTAI) from oestrus synchronisation programmes in lactating dairy cows. Relevant papers were identified via databases and auxiliary search strategies, then information was collected using a standardised data collection form. Similar studies were grouped together to create a descriptive summary of CR to FTAI and secondary outcome measures, with the creation of forest plots to visualise results. RESULTS: A total of 15 studies were identified for review: nine examined the administration of 400-500 IU eCG as part of an oestrus synchronisation programme based on intra-vaginal progesterone-releasing devices, gonadotropin-releasing hormone and prostaglandin (P4-GPG programme). The variable methodologies in the trials evaluated posed difficulties in grouping studies for further analysis and meant that there was insufficient data for a full meta-analysis. A single study reported a statistically significant increase in CR to FTAI from the addition to eCG to a P4-GPG programme in cows with anovulatory anoestrous. Four studies evaluated the addition of eCG to P4-GPG programmes in cows without visible oestrous signs; risk differences for CR to FTAI were between -1.7% and 28.8%, with three out of four studies reporting a positive effect of eCG on CR to FTAI, but all 95% CI values crossed the line of no effect. Two studies reported on the effect of eCG on 42-day pregnancy rate following a P4-GPG programme; one reported a risk difference of -4.9% (95% CI = -10.6-0.8%), while the other reported a risk difference of 7.9% (95% CI = 0.8-15%). CONCLUSIONS: The results of published studies describing the effect of eCG in P4-GPG programmes on CR to FTAI are inconsistent and further well-designed, adequately powered studies with standardised outcome measures are required to investigate its effect.

Widening access to veterinary education: descriptive analysis of ethnicity, societal representation and educational background of applicants to veterinary education in Aotearoa New Zealand.

AIMS: To describe the ethnicity of domestic applicants for selection into the professional phase of veterinary education in Aotearoa New Zealand from 2003 to 2019, and to compare this with the ethnic composition of New Zealand society. This study also aims to explore whether there are differences in the demographic features and educational background of Maori applicants compared to non-Maori applicants that may be relevant to widening access to veterinary education. METHODS: This study was conducted with a Kaupapa Maori research methodology. Data for all applicants to the Bachelor of Veterinary Science programme at Massey University (Palmerston North, NZ) from 2003 to 2019 were retrieved from the university's Student Management System and the School of Veterinary Science selection application databases. Self-identified ethnicity was analysed in four time periods (2003-2006, 2007-2012, 2013-2016, 2017-2019) defined by factors that might influence whether an individual chose to apply for selection into the veterinary programme. Gender, age, previous university experience, decile and type of high school, and being first in family to attend university were compared between Maori and non-Maori. RESULTS: From 2003 to 2019, 3,819 individuals submitted 4,802 applications for selection into the veterinary programme. Across all time periods, applicants who identified as Maori (274/4,802; 5.7%) or Pacific (56/4,802; 1.2%) were underrepresented compared to the New Zealand population (Maori 16.5%; Pacific 8.1%), while applicants who identified as European (4,035/4,802; 84%) were over-represented (70.2% of the New Zealand population). The proportion of Maori (p = 0.82) and Pacific (p = 0.31) applicants did not change over time, while the proportion of European applicants decreased from 853/968 (88.1%) to 823/977 (84.2%; p < 0.001). Compared to non-Maori, Maori applicants were more likely to have attended a lower decile school (p < 0.001), have attended a state rather than private or overseas school (p = 0.003) and to have been the first in their family to attend university (p = 0.001). CONCLUSIONS: Maori are underrepresented in the veterinary applicant pool and veterinary profession in comparison to the New Zealand population. Additionally, Maori applicants differed from non-Maori applicants in pre-university factors that are barriers to university attendance. Implementing activities and processes aimed at widening veterinary programme access with the eventual goal of improving the ethnic representation of the veterinary workforce needs to be a priority for the university and profession.

Indicators of dehydration in healthy 4- to 5-day-old dairy calves deprived of feed and water for 24 hours.

Our objective was to identify practical indicators of calf dehydration that could be used in an industry context. Eleven healthy 4-d-old commercial dairy calves were fed 2 L of mixed colostrum, then deprived of food and water for 24 h. Total body water was determined in the fed state using the deuterium dilution method. Body weight, along with a range of behavioral and physiological variables, was recorded 1 h after feeding, then at 90-min intervals through to 24 h. Blood samples were collected at every second sampling to assess changes in plasma hemoglobin, hematocrit, and osmolality. Linear mixed-effects models were used to explore associations between hydration status (% body water) and outcome variables. All calves remained bright and alert with good suckling reflexes throughout the 24-h period. After 24 h, total body water had decreased by an average of 8.4% (standard error 1.18), consistent with mild to moderate dehydration. Skin tent return time, capillary refill time, and detectable enophthalmos were associated with hydration status. Calves with skin tent return times of 3 s or longer were 4.4 percentage points less hydrated than those with return times of less than 3 s. Similarly, a capillary refill time of 3 s or longer was associated with a 4.3 percentage point reduction in hydration compared with refill times of less than 3 s. Calves with detectable enophthalmos (≥1 mm) were 3.5 percentage points less hydrated than those without enophthalmos. The skin tent, capillary refill, and enophthalmos tests are all relatively simple to perform and, although requiring the calf to be briefly restrained, can easily be performed by a single operator. The outcome of these tests was relatively consistent, in that calves above the threshold in any test were 3.5 to 4.5% less hydrated than calves below the threshold. As such, these tests may be of practical utility to identify calves with mild to moderate dehydration in an industry setting.

Noncatastrophic and catastrophic fractures in racing Thoroughbreds at the Hong Kong Jockey Club.

BACKGROUND: Reports of fractures in racehorses have predominantly focused on catastrophic injuries, and there are limited data identifying the location and incidence of fractures that did not result in a fatal outcome. OBJECTIVE: To describe the nature and the incidence of noncatastrophic and catastrophic fractures in Thoroughbreds racing at the Hong Kong Jockey Club (HKJC) over seven racing seasons. STUDY DESIGN: Retrospective cohort study. METHODS: Data of fractures sustained in horses while racing and of race characteristics were extracted from the HKJC Veterinary Management Information System (VMIS) and Racing Information System (RIS), respectively. The fracture event was determined from the first clinical entry for each specific injury. The incidence rates of noncatastrophic and catastrophic fractures were calculated per 1000 racing starts for racetrack, age, racing season, sex and trainer. RESULTS: One hundred and seventy-nine first fracture events occurred in 64,807 racing starts. The incidence rate of noncatastrophic fractures was 2.2 per 1000 racing starts and of catastrophic fractures was 0.6 per 1000 racing starts. Fractures of the proximal sesamoid bones represented 55% of all catastrophic fractures, while the most common noncatastrophic fractures involved the carpus and the first phalanx. Significant associations were detected between the incidence of noncatastrophic fractures and sex, trainer and racing season. MAIN LIMITATIONS: The first fracture event was used to calculate the incidence rate in this study and may have resulted in underestimation of the true incidence rate of fractures in this population. However, given the low number of recorded fracture events compared with the size of the study population, this underestimation is likely to be small. CONCLUSIONS: There were 3.6 times as many noncatastrophic fractures as catastrophic fractures in Thoroughbreds racing in Hong Kong between 2004 and 2011. Noncatastrophic fractures interfere with race training schedules and may predispose to catastrophic fracture. Future analytical studies on noncatastrophic racing fractures should be a priority for the racing industry.

An epidemiological investigation of an idiopathic myopathy in hunting dogs in New Zealand.

AIM: To conduct an epidemiological investigation of an idiopathic myopathy, known as "Go Slow" (GSM), which was initially recognised in dogs used for pig hunting. A secondary aim was to describe the hunting activities, diet and health of dogs used for pig hunting in New Zealand. METHODS: A retrospective cohort study was conducted between June 2014-June 2017. Cases of GSM in dogs were diagnosed by veterinarians using a combination of clinical history, physical examination findings, serum biochemistry and/or skeletal muscle histology. A telephone interview was conducted with the owner or primary veterinarian to provide information regarding the dog's diet and exercise over the 7 days preceding the onset of clinical signs. In August 2015, a separate online survey of owners of dogs used for pig hunting was conducted to characterise the normal hunting activities, diet and health of these dogs. RESULTS: A total of 86 cases of GSM were recruited, of which 58 (67%) were pig hunting dogs, 16 (19%) pet dogs and 12 (14%) working farm dogs. Cases were most commonly reported in the upper North Island, and 65 (76 (95% CI=67-85)%) were from the Northland region. Processed commercial dog food had been fed to 93 (95% CI=88-98)% of affected dogs. Ingestion of raw, frozen or cooked wild pig in the preceding week was reported for 76 (88 (95% CI=82-95)%) dogs with the myopathy. In the survey of owners of healthy pig hunting dogs, 203 eligible responses were received; pig hunting was reported to most commonly occur in Northland (20.2%), Waikato (22.3%) and Bay of Plenty (23.2%) regions. Commercial dog food was fed to 172 (85 (95% CI=80-90)%) of the dogs included in this survey, and 55 (27 (95% CI=20-33)%) had eaten wild pig in the preceding week. The most common reported health problem in pig hunting dogs was traumatic wounds. CONCLUSIONS: Cases of GSM were most commonly recognised in dogs used for pig hunting, but also occurred in pet and working farm dogs. The disease was most frequently reported in the upper North Island of New Zealand and ingestion of wild pig was a consistent feature in cases of this myopathy. CLINICAL RELEVANCE: To minimise the risk of dogs developing this myopathy, it would seem prudent to avoid feeding any tissues from wild pigs to dogs in areas where the disease is known to occur.

Evaluation of the Control Strategy for the 2010 Foot-and-Mouth Disease Outbreak in Japan Using Disease Simulation.

In 2010, Japan experienced a foot-and-mouth disease (FMD) epidemic where 292 premises were infected over a period of 75 days. The epidemic was controlled by stamping-out and vaccination, applied 5 weeks after the first confirmation of disease within a 10 km radius of identified infected places. This study aimed at identifying the role of emergency vaccination to epidemic control while adjusting for the dynamic pattern of local spread, and assessing alternative vaccination strategies, using a disease simulation model. Our results indicate that the overall hazard of local spread remained high throughout the silent spread phase and the first two weeks post-detection, with significant reduction occurring from week 3 onwards. The estimated effectiveness of emergency vaccination quantified as reduction in the hazard of infection was at most 81% and 44% for cattle and pig farms, respectively. The vaccination strategy reduced the simulated median number of IPs by 22%, epidemic duration by 64% and culling duration by 52%, but increased the total number of infected or vaccinated premises subject to culling by 144% compared with no vaccination. The simulation indicated that vaccination starting 2 weeks earlier (3 weeks post-first detection) with a smaller vaccination radius (3 km) was more effective for eradication of the epidemic compared with the actually implemented strategy.

Criteria and indicators for foot and mouth disease control strategy decision-making in Asia-Oceania countries.

The objective of this study is to identify the relative importance of criteria that could be used to evaluate control strategies for foot and mouth disease (FMD). A questionnaire was distributed to 21 Chief Veterinary Officers (CVOs), or their representatives, at the 28th Conference of the Regional Commission for Asia, the Far East and Oceania of the World Organisation for Animal Health (OIE), held on 18-22 November 2013 in Cebu, the Philippines. The CVOs/CVO representatives were present on behalf of 21 of the 31 OIE Member Countries in the region, and the questionnaire evaluated the importance of epidemiologic, economic and social- environmental criteria in the FMD control strategy decision-making process. Within the epidemiologic criterion, the size of an FMD outbreak area, with a median relative importance score of 90 (range 45-100), was viewed as the most important indicator, while the direct cost of FMD control measures was considered to be the most important economic indicator, with a median relative importance score of 80 (range 30-100). Finally, within the social-environmental criterion, the mental health of FMD-affected farmers was viewed as the most important indicator, with a median relative importance score of 70 (range 5-100). With respect to the FMD status of a country, the economic criterion was considered more important in 'FMD-free' countries (countries where an FMD outbreak had not been reported to the OIE in the ten years prior to the survey) than in 'FMD-experienced' countries (countries where an FMD outbreak had been reported to the OIE within the same period). The median relative importance scores of FMD-experienced countries and FMD-free countries were 80 (range 50-95) and 95 (range 40-100), respectively. Regarding the percentage contribution of the agriculture sector to a country's gross domestic product, a statistically significant difference was not found between countries and indicators. In the future, the current survey of the relative importance of criteria and indicators should facilitate a transparent discussion on the implications of FMD control strategies and rapid response during an FMD outbreak.

Les auteurs présentent les résultats d'une étude visant à déterminer l'importance relative des critères utilisés pour évaluer les stratégies de lutte contre la fièvre aphteuse. À cet effet, un questionnaire a été distribué à 21 Chefs des Services vétérinaires (ou leurs représentants), lors de la 28e Conférence de la Commission régionale de l'Organisation mondiale de la santé animale (OIE) pour l'Asie, l'Extrême-Orient et l'Océanie, qui s'est tenue du 18 au 22 novembre 2013 à Cebu (Philippines). Au total, 21 des 31 Pays membres de l'OIE de la région étaient représentés lors de la conférence ; le questionnaire avait pour but d'évaluer l'importance des critères épidémiologiques, économiques et socioenvironnementaux dans le processus de décision sur les stratégies de lutte à adopter contre la fièvre aphteuse. Parmi les critères épidémiologiques, la dimension de la zone affectée par un foyer de fièvre aphteuse a été considérée comme l'indicateur relatif le plus important, avec un score médian de 90 (dans une fourchette comprise entre 45 et 100). Parmi les critères économiques, le coût direct des mesures de lutte contre la fièvre aphteuse a été considéré comme l'indicateur relatif le plus important, avec un score médian de 80 (fourchette comprise entre 30 et 100). Enfin, parmi les critères socio-environnementaux, le moral des éleveurs affectés par un foyer de fièvre aphteuse a été considéré comme l'indicateur relatif le plus important, avec un score médian de 70 (fourchette comprise entre 5 et 100). L'analyse des réponses en fonction du statut des pays au regard de la fièvre aphteuse a fait apparaître que l'importance attribuée aux critères économiques était plus élevée dans les pays indemnes de fièvre aphteuse (c'est-à-dire les pays n'ayant notifié aucun foyer de fièvre aphteuse à l'OIE au cours des 10 années précédant l'enquête) que dans les pays ayant notifié un ou plusieurs épisodes de fièvre aphteuse au cours de cette même période. Les scores relatifs médians étaient respectivement de 80 (fourchette comprise entre 50 et 95) dans les pays ayant notifié un ou plusieurs épisodes de fièvre aphteuse et de 95 (fourchette comprise entre 40 et 100) dans les pays indemnes de fièvre aphteuse. Aucune corrélation significative au plan statistique n'a été constatée entre les pays et les indicateurs d'une part et la part de la production agricole dans le produit intérieur brut des pays, d'autre part. Cette enquête sur l'importance relative des critères et des indicateurs dans les processus de décision devrait faciliter à l'avenir l'examen transparent des conséquences des stratégies envisagées pour lutter contre la fièvre aphteuse ainsi que la mise en place rapide de mesures de contrôle en cas de foyers de fièvre aphteuse.

Los autores describen un estudio encaminado a determinar la importancia relativa de los criterios que cabría emplear para evaluar las estrategias de lucha contra la fiebre aftosa. Con ocasión de la 28ª Conferencia de la Comisión Regional para Asia, Extremo Oriente y Oceanía de la Organización Mundial de Sanidad Animal (OIE), celebrada del 18 al 22 de noviembre de 2013 en Cebú (Filipinas), se repartió un cuestionario entre los 21 jefes de los Servicios Veterinarios nacionales, o sus representantes, que asistieron en representación de 21 de los 31 Países Miembros de la OIE de la región. En dicho cuestionario se evaluaba la importancia de criterios epidemiológicos, económicos y socioambientales a la hora de decidir sobre estrategias de lucha contra la fiebre aftosa. Por lo que respecta a los criterios epidemiológicos, el indicador considerado más importante, con un valor mediano de importancia relativa de 90 (intervalo: 45­100), fue el de la superficie afectada por un brote de fiebre aftosa. El indicador económico juzgado más importante fue el costo directo de las medidas de lucha, con un valor mediano de importancia relativa de 80 (intervalo: 30­100). Por último, en el apartado de criterios socioambientales, el indicador considerado más importante, con un valor mediano de 70 (intervalo: 5­100), fue el de la salud mental de los productores afectados por la fiebre aftosa. Consideradas las cosas desde el ángulo de la situación sanitaria de un país con respecto a la enfermedad, el criterio económico revestía más importancia en los países «libres de fiebre aftosa¼ (aquellos que no habían notificado a la OIE brote alguno en los diez años anteriores al estudio) que en los países «con experiencia¼ en la fiebre aftosa (aquellos que habían notificado a la OIE algún brote en el curso del mismo periodo). Los valores medianos de importancia relativa de los países «con experiencia¼ y de los países libres de la enfermedad fueron, respectivamente, de 80 (intervalo: 50­95) y de 95 (intervalo: 40­100). Al considerar la contribución porcentual del sector agrícola al producto interior bruto del país no se observaron diferencias estadísticamente significativas entre países o indicadores. En el futuro, este estudio de la importancia relativa de criterios e indicadores debería facilitar un debate transparente sobre las repercusiones de las estrategias de lucha contra la fiebre aftosa y las medidas de respuesta rápida en el curso de un brote.

The incidence and risk factors for shipping fever in horses transported by air to Hong Kong: Results from a 2-year prospective study.

A 2 year prospective study was performed between February 2011 and January 2013 to determine the incidence and risk factors for shipping fever (SF) in horses transported by air to Hong Kong (HK). Using a questionnaire, data were collected from professional flying grooms regarding the journey to HK and horses in the shipment. Horses were monitored in quarantine for 2 weeks after arrival in HK, and clinical signs of SF recorded. Poisson and logistic regression models were used to identify risk factors for SF at the horse and shipment levels. The study analysed data from 869 horses on 81 flights arriving from Australia (n = 24), New Zealand (NZ; n = 18), the United Kingdom (UK; n = 33) and the United States of America (USA; n = 6). The incidence risk of SF was 10.8 per 100 horses and the proportion of shipments with at least one horse that developed SF was 49/81 (60%). The study identified that the rate per shipment of SF in shipments of horses originating from NZ, the USA and the UK was 2.40 (95% confidence interval [CI] 1.22-4.71), 2.43 (95% CI 0.66-8.89) and 3.08 (95% CI 1.60-5.93) times the rate of SF compared to Australia. Shipments arriving in HK during March and May were 5.61 (95% CI 1.55-20.31) and 4.51 (95% CI 1.43-14.26) times more likely to contain horses that developed SF compared to shipments arriving in January. The identification of these risk factors and the recognition of at-risk shipments will help focus attention on preventative strategies.

Evaluating the Effectiveness of Strategies for the Control of Equine Influenza Virus in the New Zealand Equine Population.

New Zealand has never experienced an equine influenza (EI) outbreak. The 2007 outbreak of EI in Australia showed that in a naïve population EI spreads rapidly and substantial efforts (in terms of movement restrictions, mass vaccination and post-vaccination surveillance) were required to achieve eradication. To control EI, it is essential that animal health authorities have well-defined strategies for containment, control and eradication in place before an incursion occurs. A spatially explicit stochastic simulation model, InterSpread Plus, was used to evaluate EI control strategies for the New Zealand situation. The control strategies considered were movement restrictions alone and movement restrictions in combination with one of three vaccination strategies beginning on day 14; suppressive, protective or targeted. The suppressive strategy involved vaccination in a 3 km radius around infected properties, while the protective strategy involved vaccination in a 7-10 km ring around infected properties. Targeted vaccination involved the vaccination of all breeding and racing properties within 20 km of an infected property. Simulations were carried out to determine the impact of timing of vaccination and earlier detection on the size of and duration of the outbreak. All three vaccination strategies implemented on day 14 resulted in between 1028 and 2161 fewer infected properties (P < 0.001), and an epidemic that was between 42 and 90 days shorter (P < 0.001) compared with movement restrictions alone. Any vaccination strategy implemented on day 7 resulted in fewer infected properties, compared with vaccination implemented on days 14 or 21. Overall, the suppressive vaccination strategy resulted in fewer infected properties. Our findings indicate that any vaccination strategy, if combined with complete movement restrictions could be effective for the control of EI, if an outbreak was to occur in New Zealand. If an outbreak were to occur, a simulation model has now been created to assist in decision-making using data from the actual outbreak.

Analysis of horse movements from non-commercial horse properties in New Zealand.

AIMS: To investigate property-level factors associated with the movement of horses from non-commercial horse properties, including the size and location of the property, number and reason for keeping horses. METHODS: Using a cross-sectional survey 2,912 questionnaires were posted to randomly selected non-commercial horse properties listed in a rural property database. The survey collected information about the number of horses, and reasons for keeping horses on the property, and any movement of horses in the previous 12 months. Three property-level outcomes were investigated; the movement status of the property, the frequency of movement events, and the median distance travelled from a property. Associations were examined using logistic regression and Kruskal-Wallis analysis of variance. RESULTS: In total 62.0% (488/791) of respondents reported at least one movement event in the year prior to the survey, for a total of 22,050 movement events. The number of movement events from a property varied significantly by the number of horses on the property (p<0.02), while the median distance travelled per property varied significantly by both region (p<0.03) and property size (p<0.01). Region, property size, the number of horses kept, and keeping horses for competition, recreation, racing or as pets were all significantly associated with movement status in the multivariable analyses (p<0.001). CONCLUSION AND CLINICAL RELEVANCE: This study showed that there are characteristics of non-commercial horse properties that influence movement behaviour. During an exotic disease outbreak the ability to identify properties with these characteristics for targeted control will enhance the effectiveness of control measures.

An investigation of the movement patterns and biosecurity practices on Thoroughbred and Standardbred stud farms in New Zealand.

Utilising a face-to-face interview of stud managers, a survey was conducted to investigate the movement patterns around, and biosecurity practices on, Thoroughbred and Standardbred stud farms. Eligible stud farms (n=60) were identified from the 2009 Thoroughbred stallion register and 2009 Standardbred stallion register, and stud managers were asked to participate in the interview. In total, 27 stud managers agreed to participate in the study, and participating stud farms included 38% of Thoroughbred and 60% of Standardbred mares bred in 2009. All stud managers reported the movement of horses to and from their stud farm. The median number of movement events per year was 127 (interquartile range 83-300). The frequency of movement events from a stud farm was not associated with the breed of horse managed on the stud farm, however Thoroughbred horses travelled further than Standardbred horses during these movement events (P<0.001). The movement patterns of horses around stud farms showed a strong seasonality associated with the commercial breeding season of each breed. While 26 (96%) of stud managers reported having procedures in place for checking newly arriving horses, only 6 (22%) stud managers reported isolating horses on arrival as a standard protocol. The main reason for isolating horses on properties, where isolation was not a standard procedure, was in response to strangles outbreaks on other stud farms (n=10). Only 2 (7%) stud managers reported implementing visitor protocols, and these protocols only applied to visiting veterinarians, but not to farriers. These findings have important implications for the control of both endemic and exotic infectious disease outbreaks within the New Zealand breeding population as the high frequency of movement around stud farms, the high number of visitors to stud farms and the lack of effective biosecurity practices or visitor protocols will be critical factors in the spread of equine influenza during an outbreak.

Cohort study examining long-term respiratory health, career duration and racing performance in racehorses that undergo left-sided prosthetic laryngoplasty and ventriculocordectomy surgery for treatment of left-sided laryngeal hemiplegia.

REASONS FOR PERFORMING STUDY: The risk of respiratory conditions, such as inflammatory airway disease (IAD) and exercise-induced pulmonary haemorrhage (EIPH), are thought to be higher in racehorses that undergo prosthetic laryngoplasty with ventriculocordectomy (PLVC) surgery to treat left-sided laryngeal hemiplegia (LLH) than in racehorses with normal laryngeal function. However, this has not been investigated formally owing to the difficulty of obtaining reliable follow-up data. OBJECTIVES: To determine the incidence of respiratory conditions (IAD and EIPH), duration of racing career, number of starts and number of starts for which stakes money was earned in racehorses that had undergone PLVC surgery to treat LLH, compared with racehorses that did not have LLH or undergo any laryngeal surgery. METHODS: A retrospective cohort study design was used, with surgical, clinical and race data of Thoroughbred racehorses obtained from the time of importation until retirement. The surgical cohort consisted of racehorses that had undergone PLVC for LLH and met specific inclusion criteria. Every surgical case was matched, according to trainer, year of import into Hong Kong and pre-import international handicap rating, to 2 unexposed racehorses. RESULTS: Respiratory conditions, such as excessive tracheal mucus and epistaxis due to severe EIPH, were significantly increased in the surgical cohort, compared with the matched unexposed cohort (P values <0.001 and <0.004, respectively). Racing career duration in the surgical cohort was significantly shorter than in the unexposed cohort, which was primarily due to retirement because of epistaxis. The number of race starts was fewer in the surgical than in the unexposed cohort after surgery/matching, but the number of starts for which stakes money was earned was not significantly different. CONCLUSIONS AND POTENTIAL RELEVANCE: Owners and trainers should be advised that racehorses with LLH that undergo PLVC surgery are at an increased risk of respiratory conditions (IAD and severe EIPH), which is likely to shorten their racing career compared to racehorses with normal laryngeal function. Racing performance in terms of race starts was significantly less in racehorses that had undergone PLVC surgery; however, the number of starts for which stakes money was earned was similar to those racehorses that were unexposed.

A description of the demographic characteristics of the New Zealand non-commercial horse population with data collected using a generalised random-tessellation stratified sampling design.

We conducted a cross-sectional survey to determine the demographic characteristics of non-commercial horses in New Zealand. A sampling frame of properties with non-commercial horses was derived from the national farms database, AgriBase™. Horse properties were stratified by property size and a generalised random-tessellated stratified (GRTS) sampling strategy was used to select properties (n=2912) to take part in the survey. The GRTS sampling design allowed for the selection of properties that were spatially balanced relative to the distribution of horse properties throughout the country. The registered decision maker of the property, as identified in AgriBase™, was sent a questionnaire asking them to describe the demographic characteristics of horses on the property, including the number and reason for keeping horses, as well as information about other animals kept on the property and the proximity of boundary neighbours with horses. The response rate to the survey was 38% (1044/2912) and the response rate was not associated with property size or region. A total of 5322 horses were kept for recreation, competition, racing, breeding, stock work, or as pets. The reasons for keeping horses and the number and class of horses varied significantly between regions and by property size. Of the properties sampled, less than half kept horses that could have been registered with Equestrian Sports New Zealand or either of the racing codes. Of the respondents that reported knowing whether their neighbours had horses, 58.6% (455/776) of properties had at least one boundary neighbour that kept horses. The results of this study have important implications for New Zealand, which has an equine population that is naïve to many equine diseases considered endemic worldwide. The ability to identify, and apply accurate knowledge of the population at risk to infectious disease control strategies would lead to more effective strategies to control and prevent disease spread during an exotic, infectious disease outbreak, but could also highlight groups within the population that require targeted surveillance.

The implementation of biosecurity practices and visitor protocols on non-commercial horse properties in New Zealand.

A survey was conducted to investigate biosecurity practices on non-commercial horse properties, to describe the number of visits by horse professionals and any protocols that visitors were required to follow before interacting with resident horses. Data were collected in November 2009 during a cross-sectional study of non-commercial horse properties, in New Zealand, selected using generalised random-tessellated stratified design and a self-administered postal questionnaire. Data were described and the associations between property-level factors and biosecurity practices were analysed using logistic regression analysis. In total there were 791 respondents from non-commercial horse properties, of which 660 (83%) answer at least one question relating to biosecurity practices. Of the respondents, 95% had at least one biosecurity practice for arriving horses. Only 31% of properties isolated horses for more than four days, and few respondents checked for pyrexia or other clinical signs of infectious disease in new horses. Moving horses from a property was associated with the implementation of biosecurity practices and practices specific to the clinical signs of respiratory disease. Overall, 79% of properties had horse professional's visit, but only 33% of respondents reported biosecurity protocols for these visitors. Most properties had some knowledge about newly arriving horses, but the effectiveness of these practices for biosecurity were questionable, as few practices would stop disease spread to resident horses. Horse professionals are likely candidates for disease spread due to contact with horses, limited visitor protocols and the frequency of visits. The development of a plan to improve biosecurity for endemic and exotic disease is recommended.

A retrospective study of gastric dilatation and gastric dilatation and volvulus in working farm dogs in New Zealand.

AIMS: To present findings from a case series of gastric dilatation (GD) or gastric dilatation and volvulus (GDV) in working farm dogs in New Zealand that were examined at veterinary clinics, and to identify possible risk factors for GD or GDV in working farm dogs in New Zealand using a case-control study. METHODS: This retrospective study included a case-series and a case-control study. The case series analysed information from 62 case records of GD or GDV in working farm dogs seen between August 2004 and September 2009 at 13 veterinary clinics throughout New Zealand. Cases were classified as GD or GDV if the diagnosis was confirmed by radiography, surgery or post-mortem examination. Details of history and treatment, as well as outcomes, were obtained for each case. For the case-control study, records of 41 working farm dogs with GD or GDV (cases) seen between April 2008 and April 2009, and 82 working farm dogs examined because of trauma over the same period and in the same 13 clinics (controls), were used to model the risk factors for GD or GDV. RESULTS: From the case-series study, 40/62 (65%) cases of GD or GDV that were examined and treated at the veterinary clinics returned to work. Of the 41 dogs where the gastric contents were recorded, 25 (61%) had predominantly food or bones in the stomach, and 26/27 dogs had a history of having eaten meat, bones or scavenged a carcass. The case-control study showed that the significant risk factors for GD or GDV, compared with control dogs presenting with trauma, were breed, age and season. The odds that a case of GD or GDV was a Huntaway, after adjusting for age and season, was 19 times higher than the odds a control was a Huntaway. Gender and bodyweight were not identified as risk factors. CONCLUSIONS AND CLINICAL RELEVANCE: A high proportion of farm working dogs with GD or GDV were successfully treated by veterinarians. The risk of a case of GD or GDV being a Huntaway was significantly higher than for a dog presenting as a trauma case. However the influences of the season of the year, climatic factors and nutritional factors on the pathogenesis need to be identified before adequate preventative measures can be recommended.

Evaluation of post-farm-gate passive surveillance in swine for the detection of foot and mouth disease in Australia.

Pigs are considered high risk for the introduction and spread of foot and mouth disease (FMD) in Australia. One of the most likely pathways of introduction of FMD into Australia would be through the illegal importation of FMD-contaminated meat, which is then fed to feral or domestic pigs. Locations where animals from different origins are commingled, such as livestock markets and abattoirs, pose a risk for disease spread. Early detection of exotic diseases at these locations is crucial in limiting the spread of an outbreak. The aims of this study were to evaluate the likelihood of exotic disease detection with current passive disease surveillance activities for pigs at saleyards and abattoirs in eastern Australia, and make recommendations for improving surveillance. Sensitivity (Se) of the current post-farm-gate passive surveillance for detection of exotic diseases was estimated using the scenario tree modelling methodology (Martin et al., 2007a). Four surveillance system components were identified: (i) domestic saleyard, (ii) export saleyard, (iii) domestic abattoir, and (iv) export abattoir. Pig farms were classified according to herd size (Small vs. Large) and subsequently into two risk categories depending on the probability of swill feeding (Swill feeding vs. Not swill feeding). A scenario tree representing the pathways by which infected animals could be detected was developed and the Se of detection in each surveillance system component was estimated. Industry statistics, information on previous exotic disease outbreaks, and interviews with pig producers were used to estimate herd category proportions and the relative risk of swill feeding. Quantitative estimates for probabilities of detection were sourced from State legislation and policies, stakeholder consultation and observational studies at saleyards and abattoirs. Results of a FMD case study showed a Se of detection at a representative location for each surveillance system component during a 2-week period of 0.19 at domestic saleyards, 0.40 at export saleyards, 0.32 at domestic abattoirs and, 0.53 at export abattoirs. This output assumed the country was infected with herd and unit design prevalences of 1% and 30%, respectively. Improving disease awareness of saleyard and abattoir stockmen, increasing the presence of inspectors at these venues and identifying those herds posing a higher risk for FMD introduction, could improve the capacity of the country for early detection of emerging animal diseases.

Herd management practices and the transmission of Johne's disease within infected dairy herds in Victoria, Australia.

A retrospective cohort study involving 137 dairy herds randomly selected from all 390 participating in the Victorian Test and Control Program for bovine Johne's disease was undertaken to gain insight into the relationships between calf rearing practices and the occurrence of bovine Johne's disease on infected dairy farms. Each study farm was visited between July 2005 and January 2006 and a structured survey examining herd management and calf rearing practices was completed. The resultant data, along with information from annual herd testing for Johne's disease and records of clinical Johne's disease diagnosed in the herd, from May 1990 to March 2008, were analysed. Factors associated with time to the birth of the animal that was the first home-bred clinical case of Johne's disease or ELISA positive animal born after the second annual whole herd test in the herd were investigated using survival analysis methods. The publicly-subsidised Test and Control Program commenced in 1996. On the 1st of July 2003 the program was modified with more rigorous and externally audited calf rearing requirements introduced for all participants. The more stringent calf rearing requirements introduced in July 2003 appear to have translated into significantly reduced disease transmission within the infected study herds.

A cross-sectional survey of biosecurity practices on Thoroughbred stud farms in New Zealand.

AIM: To examine the on-farm biosecurity practices of a group of commercial Thoroughbred stud farms in the North Island of New Zealand, in the absence of an exotic disease outbreak. METHODS: A cross-sectional survey of biosecurity practices was conducted during the 2006/2007 Thoroughbred breeding season, and consisted of data from commercial Thoroughbred farms in the North Island of New Zealand standing a stallion. Data were collected on-farm by a single interviewer, using 17 open, closed and multiple-choice questions examining general farm/operation size and features, general animal health and biosecurity practices, biosecurity practices in relation to breeding stock, and opinions about the application of on-farm quarantine measures. Data were examined for differences in biosecurity practice between farms with and without shuttle stallions, and differing in size. RESULTS: Data were collected from 28/34 selected farms during the 2006/2007 breeding season. Thirteen farms were classified as small, 10 medium, and five large; shuttle stallions were present on 12 farms. Commercial transporters were responsible for the delivery of 79% (3,116/3,945) of the mares. On arrival non-resident mares were rarely isolated though they were screened for cough (25/28; 89%) or nasal discharge (28/28; 100%); constraints on implementing arrival quarantine protocols for such mares were time (5/28; 18%), space (11/28; 39%), and staff workload (4/28; 14%). In the absence of disease, few farms (3/28; 11%) implemented protocols between cohorts of horses. However, focal points of high interaction between horses, such as foaling paddocks, isolation yards and crushes, were regularly cleaned and/or disinfected. In the presence of disease, the vast majority of farms (92-100%) implemented control measures such as changing clothes and washing hands between cohorts. Stallions were rarely quarantined on arrival. If the stallion was imported many considered pre-importation quarantine to be sufficient. Farms with shuttle stallions were more likely to have an arrival protocol in place than those that did not (92% vs 50%; p<0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Most stud managers were aware of the need for on-farm biosecurity; management constraints meant that protocols might not always be followed. The absence of an exotic disease outbreak and the overwhelming confidence of stud managers in the Ministry of Agriculture and Forestry (MAF) in preventing an exotic disease incursion were reasons for a lack of implementation of on-farm biosecurity protocols.

A survey of diseases of working farm dogs in New Zealand.

AIMS: To record the incidence of specific diseases affecting working farm dogs; identify any apparent breed predispositions; determine the most important causes of loss from death, euthanasia, or retirement of the dog; and identify potential interventions that could reduce the incidence of disease. METHODS: A national questionnaire-based cross-sectional study was conducted to identify the incidence of specific diseases, and circumstances of trauma affecting working farm dogs that presented to rural veterinary practices over a 12-month period, between April 2008 and April 2009. The practices were convenience-sampled on the basis of geography and size. RESULTS: Sixty-six practices were approached, and veterinarians from 30 practices agreed to participate, with representation from all major rural regions of New Zealand. Data were provided on 2,214 presentations, excluding revisits, of which 51% were for Huntaways and 39% Heading dogs. Trauma was identified as a cause of injury in 848 (38%) visits. Huntaways were apparently over-represented in cases of constipation, gastric dilatation-volvulus (GDV), theriogenological problems, laryngitis, hip dysplasia, and degenerative lumbosacral disease. In contrast, Heading dogs were over-represented among cases of multiple ligamentous injury of the stifle, disruption of the gastrocnemius or Achilles tendon, tarsal injuries, and hip luxation. Traumatic injury involved injury by stock (20%), automotive incidents (19%), transit across fence lines (16%), and dog bites (12%). Loss occurred following 10% of visits, of which trauma was known to be involved in 32%. The most important non-traumatic causes of loss were GDV, degenerative joint disease, mammary neoplasia and diseases involving the female reproductive tract, cardiac disease, and poisoning. CLINICAL RELEVANCE: Several important diseases appear amenable to intervention through nutrition, neutering, or behavioural modification, including constipation, GDV, theriogenological problems, dog-bite injuries, and laryngitis. Altering modes of transit across fence lines has the potential to reduce large numbers of serious orthopaedic injuries to working farm dogs.

Quantitative risk assessment for the annual risk of exposure to Trichinella spiralis in imported chilled pork meat from New Zealand to Singapore.

AIMS: To determine the annual likelihood of exposure to an infectious dose of Trichinella spiralis from consuming imported pork meat from New Zealand to Singapore. METHODS: Input values specific for chilled pork meat imported into Singapore from New Zealand were used in a quantitative risk-assessment model. The model, designed to allow any combination of importing and exporting countries, was divided into two components, viz the release assessment, and the exposure assessment that assessed the annual risk of exposure to the consumer (ARC). The former estimated the likelihood that a contaminated fresh meat product from New Zealand would arrive at Singapore's border, and took into consideration the prevalence of disease on different types of farms. The latter determined the likelihood over a year that a person in Singapore would consume one or more servings of imported fresh meat from New Zealand that contained a burden of greater than or equal to one larva(e) of T. spiralis per gram after preparation for consumption. RESULTS: The ARC for offal was 2.41 x 10(-7), which was below the pre-selected safety threshold of 1.00 x 10(-6). The ARC for lean meat was 2.39 x 10(-5), which was above the acceptable safety threshold. CONCLUSIONS: The study demonstrated that continued routine testing at slaughter is unnecessary for pig offal produced commercially, and provided a model with which to further assess management of the risk of exposure to T. spiralis in lean meat. CLINICAL RELEVANCE: The potential of Trichinella species to cause disease in humans is a public health concern, and has created adverse effects on the international trade of fresh lean meat without regard to the surveillance measures employed by particular pork-producing countries.