Farm management and husbandry practices associated with spontaneous humeral fractures in New Zealand dairy heifers.

AIMS: To use a farm-based survey to identify characteristics of the New Zealand dairy system associated with the risk of spontaneous humeral fracture in dairy heifers. METHODS: A questionnaire was designed and made available in print and online to collect information from dairy farmers and/or veterinarians, across New Zealand, about the management and nutrition of cows from birth to first lactation. Data were collected from July 2019 to March 2020 from farms that either had recorded (case farms) or not recorded (control farms) cases of humeral fractures in dairy heifers. RESULTS: A total of 68 completed questionnaires were returned, with 35 responses from case farms and 33 responses from control farms. Twenty-six responses (38%) were from the South Island (13 case farms and 13 control farms) and 38 responses (56%) were from the North Island (20 case farms and 18 control farms). For four questionnaires (6%) farm location was not given. Adjusting for the effect of age when calves accessed pasture, case farms had increased odds of having Holstein-Friesian Jersey crossbreed cows as the predominant breed (OR = 9.7; 95% CI = 3.1-36.0; p < 0.001). Adjusting for the effect of breed, allowing calves access to pasture a week later decreased the odds of being a case farm (OR = 0.68; 95% CI = 0.47-0.90; p = 0.006). CONCLUSIONS: Cows being Holstein-Friesian Jersey crossbreed was identified as a possible risk factor associated with spontaneous humeral fracture in dairy heifers in New Zealand. Given the small sample size, the likely multifactorial aetiology for humeral fractures, and the non-randomised survey, this risk factor, and the possible association between age at turn out and herd production with humeral fractures, all require further investigation.

Preliminary examination of the perceptions of sustainable horse feeding practices in the Netherlands.

The purpose of this study was to determine the perception of sustainability among horse owners in the Netherlands and their willingness to switch to more sustainable feeding practices. A survey was distributed to a target group of horse owners in the Netherlands via social media channels. Data (n = 338 valid responses) were stratified based on yard type and size (small (<20), medium (20-50), and large (>50 horses). Most of the yards were livery yards (68 %) and they were small in size (66 %). The term most commonly associated with sustainability was low environmental impact (61.8 %). All participants (338/338) indicated that they were willing to switch to more sustainable feeding practices. Of the six options offered, the most popular was the use of plastic-free packaging products (60.5 %). This study identified that numerically the greatest change in behavior for the Dutch equestrian community would be achieved by small livery yards (P < 0.001). The potential to modify certain practices might be limited by the size of the equestrian operation, such as the available land for altering pasture management, and the financial aspects of the enterprise. Future research should investigate how the scale and economic considerations of the equestrian business influence its capacity and willingness to adopt more sustainable feeding practices.

Biochemical profile of heifers with spontaneous humeral fractures suggest that protein-energy malnutrition could be an important factor in the pathology of this disease.

CASE HISTORY: Serum and liver samples from 35, 2-year-old dairy heifers that had fractured one or both humeri post-calving between July and December 2019 were submitted to a diagnostic laboratory for analysis. Serum samples were analysed for albumin, ß-hydroxybutyrate (BHB), creatinine, Ca, Mg, phosphate, non-esterified fatty acids (NEFA), and serum Cu concentration. Liver samples were analysed for liver Cu concentration. Data were compared to published reference intervals. Data values for heifers that prior to fracture had grazed fodder beet were also compared to values for those that had grazed pasture. CLINICAL FINDINGS: Sixty-nine percent of heifers with humeral fracture had serum creatinine concentrations below the lower value of the reference range (55-130 µmol/L). In 3/32 (9%) heifers, serum NEFA concentrations were increased above the reference value indicating body fat mobilisation (≥1.2 mmol/L for peri-partum cows) and in 20/35 (57%) heifers BHB serum concentrations were above the reference value indicating subclinical ketosis (≥1.1 mmol/L for peri-partum cows). In 24/35 (69%) heifers, liver Cu concentration was low (≤ 44 µmol/kg) or marginal (45-94 µmol/kg). The concentration of Cu in serum was low (≤ 4.5 µmol/L) in 2/33 (6%) heifers and marginal (4.6-7.9 µmol/L) in 5/33 (15%) heifers. There was moderate positive correlation between the logged concentrations of Cu in paired liver and serum samples, r(31) = 0.43; (95% CI = 0.1-0.79; p = 0.014). One heifer had a serum phosphate concentration below the lower limit of the reference range (< 1.10 mmol/L). For all heifers, the concentrations of albumin, Ca, and Mg in serum were within the reference intervals (23-38 g/L, 2.00-2.60 mmol/L, and 0.49-1.15 mmol/L respectively). Over winter, 15/35 (43%) heifers grazed predominantly pasture, 14/35 (40%) grazed fodder beet and 6/35 (17%) had a mixed diet. CLINICAL RELEVANCE: In some of these heifers with humeral fractures, there was evidence for protein and/or energy malnutrition in the form of elevated NEFA and BHB concentrations and low creatinine concentrations in serum. Liver Cu concentrations were also reduced in most affected heifers. However, the absence of a control group means it is not possible to determine if these are risk factors for fracture or features common to all periparturient heifers. Clinical trials and molecular studies are needed to determine the true contribution of Cu and protein-energy metabolism to the pathogenesis of spontaneous humeral fractures in dairy heifers. ABBREVIATIONS: BHB: ß-hydroxybutyrate; NEFA: Non-esterified fatty acids.

Infrared spectroscopy of serum fails to identify early biomarker changes in an equine model of traumatic osteoarthritis.

OBJECTIVE: to determine the accuracy of infrared (IR)-based serum biomarker profiling to differentiate horses with early inflammatory changes associated with a traumatically induced model of equine carpal osteoarthritis (OA) from controls. METHOD: unilateral carpal OA was induced in 9 of 17 healthy Thoroughbred fillies, while the remainder served as sham operated controls. Serum samples were obtained before induction of OA (Day 0) and weekly thereafter until Day 63 from both groups. Films of dried serum were created, and IR absorbance spectra acquired. Following pre-processing, partial least squares discriminant analysis (PLSDA) and principal component analysis (PCA) were used to assess group and time differences and generate predictive models for wavenumber ranges 1300-1800 â€‹cm-1 and 2600-3700 â€‹cm-1. RESULTS: the overall correct classification rate when classifying samples by group (OA or Sham) was 52.7% (s.d. â€‹= â€‹12.8%), while it was 94.0% (s.d. â€‹= â€‹1.4%) by sampling Day. The correct classification results by group-sampling Day combinations with pre-intervention serum (Day 0) was 50.5% (s.d. â€‹= â€‹21.7%). CONCLUSION: with the current approach IR spectroscopic analysis could not differentiate serum of horses with induced carpal OA from that of controls. The high classification rate obtained by Day of sampling may reflect the effect of exercise on the biomarker profile. A longer study period (advanced disease) or naturally occurring disease may provide further information on the suitability of this technique in horses.

Risk factors for horse falls in New Zealand Thoroughbred jumps racing.

This study aimed to determine the incidence of, and risk factors for race-day horse falls in Thoroughbred jumps (hurdle and steeplechase) racing in New Zealand. Incidence rates for race-day horse falls in jumps races from 2005/6 - 2018/19 racing seasons (n = 13,648 race day starts) were calculated per 1000 starts. Univariable and multivariable analyses of race-, horse- and jockey-level risk factors for horse falls were conducted using Poisson regression in a generalised linear mixed model. The incidence rate of horse falls in jumps races was 42 (95 % confidence intervals [CI], 39 - 45) per 1000 starts. Horse falls in steeplechase races were 1.6 (95 % CI, 1.4 - 1.9) times more likely than hurdle races. The incidence rate ratio (IRR) for horses falling at the last three jumps in comparison with the first three jumps was 3.1 (95 % CI, 2.8 - 3.5) for hurdle and 4.4 (95 % CI, 3.9 - 5.0) for steeplechase races. Greater jockey (age, P = 0.02) and horse experience (P = 0.001) were associated with a lower IRR of falls (P = 0.05). Longer races (P = 0.02) and those held in autumn compared to winter (IRR 1.4; 95 % CI, 1.0 - 1.8; P = 0.05) were associated with a higher rate of falling in steeplechase races. A regulatory change enhancing discretionary ability of jockeys to pull up 'in-race' was associated with reduced horse falls (IRR 0.65; 95 % CI, 0.51 - 0.82; P = 0.001). Pragmatic rule changes within the industry can have a positive effect on reducing risk and improving equine welfare.

A retrospective descriptive analysis of race-day injuries of greyhounds in New Zealand.

OBJECTIVES: To describe the distribution, and determine the incidence, of veterinary reported injuries experienced by greyhounds during racing in New Zealand. MATERIALS AND METHODS: This retrospective cohort study utilised data obtained on all greyhound race starts and all racing injuries sustained in New Zealand between 10 September 2014 and 19 June 2019. Greyhound injuries were described by the number and percentage of the type, location, and presumed cause of injuries. The overall incidence of injuries per 1000 racing starts was calculated and stratified incidence rates were calculated for race year, racetrack, race number, sex of the greyhound, country of origin of the greyhound, starting box number, race type, race class and race distance. Poisson regression was used to calculate incidence rate ratios for the outcome of injury and race exposure variables. RESULTS: There were 213,630 race starts and 4100 injuries. The incidence of injury was 19.2 per 1000 starts, while the number of fatalities at the track was 1.3 per 1000 race starts. Most injuries experienced by greyhounds on race-day were minor (soft-tissue). Most injuries affected the limbs of the greyhounds (82.8%, n = 3393/4100). The rate of injuries was higher in Australian dogs compared with New Zealand dogs, the incidence rate of injury increased with advancing age group and the incidence rate varied among racetracks. CONCLUSION: The injury rates were similar to those previously reported for racing greyhounds in New Zealand. This study highlighted the need for greater uniformity and conciseness around the classification of injuries to permit comparisons across jurisdictions.

Cross-sectional survey of parasite control practices on Thoroughbred and Standardbred training yards in New Zealand.

REASONS FOR PERFORMING STUDY: There is growing concern worldwide regarding anthelmintic resistance in equine parasites. In order to improve parasite control practices and reduce the selection for resistant parasites, baseline data are required. OBJECTIVES: To describe the current parasite management and control practices used for racehorses. STUDY DESIGN: Cross-sectional survey. METHODS: Thoroughbred and Standardbred trainers were surveyed online regarding demographics, parasite control methods, grazing management and quarantine, and the use of faecal egg counts (FEC), with questions stratified by horse type, i.e. racehorses (horses in training) and spellers (racehorses on a break from training), and industry (Thoroughbred and Standardbred). Multivariable logistic regression was used to examine associations with FEC use. RESULTS: In total, 234 respondents completed the survey for an estimated response rate of 16%. In total, 50.5% of trainers treated horses on an interval treatment strategy and treated a median of 6 (interquartile range (IQR) 4-7) and 6 (IQR 4-8) times annually for Thoroughbred and Standardbred racehorses, respectively. A total of 62.5% (130/208) of respondents reported seeking veterinary advice for deworming products, and FEC had been done by 20.1% (39/194) of respondents. The odds of a trainer doing FEC were 4 times higher if the trainer had consulted a veterinarian, compared with those that had not. CONCLUSIONS: This study has highlighted an industry-wide overuse of anthelmintic products and few trainers were using surveillance-based control strategies. The relationship between veterinarians and trainers should be explored further to enhance information dissemination and implement effective control strategies, to maintain horse health and delay the advance of anthelmintic resistance.

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.

Sub-optimal efficacy of ivermectin against Parascaris equorum in foals on three Thoroughbred stud farms in the Manawatu region of New Zealand.

AIM: To ascertain whether resistance was present in Parascaris equorum to the macrocyclic lactone anthelmintic ivermectin, using faecal egg count reduction tests. METHODS: Thirty-nine foals aged between 11 and 28 weeks on three Thoroughbred stud farms (Farms A; n=20, B; n=5 and C; n=14) were treated with ivermectin (Day 0) and faecal egg counts (FEC) were monitored before and for 21 (Farms A and B) or 14 (Farm C) days after treatment. On Farms A and B, the foals were treated with a macrocyclic lactone/benzimidazole/praziquantel combination on Day 21 and FEC assessed on Day 35. The three farms were all in the Manawatu region in the southern half of New Zealand's North Island. RESULTS: Of the 39 foals, 15 were not shedding P. equorum eggs on the day they were treated with ivermectin, but all 15 did so post-treatment. The FEC on Farms A and B showed no evidence of a reduction at any time between Day 7 and 21; egg output increased steadily over this period. Following combination treatment FEC were reduced by 94% on farm A and 100% on Farm B. On Farm C, there was a 69% reduction in P. equorum FEC on Day 14. Twelve of the 14 foals on Farm C were shedding strongylid eggs on Day 0 and on Day 14 FEC were reduced by 84%. CONCLUSIONS: Without comparison to untreated control animals, these results do not allow a reliable estimation of the exact level of efficacy of ivermectin against P. equorum, but they nevertheless show that, within the farms studied, ivermectin no longer achieved a complete kill of egg-laying adults and that foals treated with this drug may continue to shed considerable numbers of eggs after treatment. The results also indicate that ivermectin had sub-optimal efficacy against strongylid nematodes on one of the farms.

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.

The effect of interruptions during training on the time to the first trial and race start in Thoroughbred racehorses.

Few studies have investigated the effect of having interruptions during training on future training and racing performance in Thoroughbred racehorses. The aim of this paper was to investigate the effect of having an interruption before the first trial on starting in a trial or a race. A prospective cohort study was used to record the training activity of a cohort of Thoroughbred racehorses, over two racing seasons. Fourteen racehorse trainers recorded information on the distances worked at canter and at fast speeds (<15s/200 m) and provided reasons for horses not training, or for having interruptions (break from training). Trial and racing results were obtained from the New Zealand Thoroughbred Racing online database. A Cox proportional hazards regression model was used to investigate two outcome measures of performance: (1) time to the first trial and (2) time to the first race. The type of interruption that had occurred before the first trial was the main exposure of interest, and was grouped into: no interruption, voluntary (no known condition or disease present) and involuntary interruptions (due to the presence of a condition or disease). A total of 160/200 (80%) horses started in at least one trial and 100/205 (48%) horses started in at least one race during the study period. The median time to starting in a trial or a race differed significantly (p<0.001) with the type of interruption. The hazard of starting in a trial was lower for horses experiencing voluntary and involuntary interruptions (p<0.001) but there was no association with starting in a race, after adjusting for confounding variables. As age at the start of training increased the hazard of starting in a trial decreased. Horses accumulating longer distances at 15s/200 m had a higher hazard of starting in a trial, whilst horses accumulating fewer events at high speed and fewer trials had a reduced hazard of starting in a race. There was significant clustering at the trainer level for both the outcomes investigated. Interruptions to training had an effect on the time to, and hazard of, a trial but not a race start. The timing of these interruptions may have implications for future racing success and career longevity.

The association of 2-year-old training milestones with career length and racing success in a sample of Thoroughbred horses in New Zealand.

REASONS FOR PERFORMING STUDY: There is increasing evidence that exercise early in life has a positive effect on musculoskeletal health. At present, there is little whole population research investigating the effect of racing as 2-year-olds on future racing career. OBJECTIVES: To investigate the association between attaining training milestones as 2-year-olds with length of career and racing success in Thoroughbred horses in New Zealand. METHODS: Retrospective data were obtained of the 2001/02-born Thoroughbred foal crop. The 3 training milestones were: registered with a trainer, trialled and raced. The association of the training milestones with career length was measured using the outcomes: number of race starts and number of years raced, in a Cox regression model. Logistic regression models analysed the association of the training milestones with the outcomes: won or placed in a race. Linear regression was performed to assess the association of training milestones with total career earnings. RESULTS: Of 4683 horses in the population; 3152 horses were registered with a trainer, 2661 horses trialled and 2109 horses raced. Horses that raced as 2-year-olds had significantly (P<0.001) more race starts than those first raced as 3-year-olds or older, this was also true when the 2-year-old year data were omitted. Horses that raced as 2-year-olds had significantly (P<0.001) more years racing. Horses registered with a trainer, trialled or raced as 2-year-olds were more likely to have won or been placed in a race than those that achieved the milestones as 3-year-olds or older. Horses that first trialled and raced as 2-year-olds had greater total earnings than those that first trialled or raced at a later age. CONCLUSIONS AND POTENTIAL RELEVANCE: Two-year-old training milestones had a strong association with positive racing career outcomes. Horses in training or racing as 2-year-olds may have better musculoskeletal health throughout life than horses that are first in training or racing at a later age.

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.

Risk factors for interruptions to training occurring before the first trial start of 2-year-old Thoroughbred racehorses.

AIM: To quantify the time from the start of training to the first interruption and to identify horse and training risk factors for voluntary interruptions and interruptions due to musculoskeletal injury occurring before the first trial. METHODS: A prospective cohort study was used to collect data on the training activity of 2-year-old racehorses, from 14 trainers in the Northern and Central Districts of New Zealand, over two racing seasons (2008/09 and 2009/10). Daily training data were recorded for each horse, including, distances worked at canter (>15 seconds/200 m), three measures of high-speed exercise (15, 13, and <12 seconds/200 m) and reasons why horses were not working. Competing risks survival analysis was used to investigate associations between risk factors and voluntary interruptions (no known condition or disease present), or interruptions due to musculoskeletal injury occurring before the first official trial. RESULTS: A total of 205 horses spent 11,051 training days at risk of an interruption before the first trial. There were 134/205 (65.4%) cases of interruptions, of which 115/134 (85.8%) were voluntary interruptions and 19/134 (14.2%) were due to musculoskeletal injury. In the final multivariable models, the risk of voluntary interruptions decreased with increasing age at the start of training, and increased with the number of days off during training, but was not associated with gender. Females had a decreased risk of interruptions due to musculoskeletal injury compared with males. There was no association between the number of high-speed events and either voluntary interruptions or interruptions due to musculoskeletal injury. CONCLUSIONS AND CLINICAL RELEVANCE: The study highlighted horse and training risk factors associated with two types of interruptions occurring during training. Identification of modifiable risk factors may help to reduce the proportion of horses experiencing an interruption before the first trial start, reducing the number of lost training days and the associated cost.

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.

Gestation length and occurrence of daytime foaling of Standardbred mares on two stud farms in New Zealand.

AIMS: To examine the gestation lengths and occurrence of daytime foaling of Standardbred mares foaling outdoors at stud farms in Southland, New Zealand (latitude 45˚S). METHODS: Data were collected prospectively at two commercial Standardbred stud farms (Farms A and B), during the 2008/9 and 2009/10 breeding seasons (October to February). For each foaling, the identity of the mare, date and time of foaling, gender of foal, time the mare passed the fetal membranes, time the foal stood, and foaling problems including dystocias, were recorded. The effect of farm, season, gender of foal, month of artificial insemination (AI) or foaling, age and parity of mare on gestation length, percentage of mares foaling during daylight hours, and percentage of foalings recorded as dystocia, were examined. RESULTS: A total of 614 foaling records were obtained from 507 mares. For 594 foalings with complete records, mean gestation length was 349 (SE 0.5) days. Mean gestation length was shorter for fillies (347.8 (SE 0.6) days) than colts (350.3 (SE 0.6) days) p = 0.021) and decreased with month of AI, from October to February (p = 0.001). The time of foaling was bimodally distributed with the primary peak around 0200 hours and a secondary smaller peak around 1300 hours. The percentage of mares foaling in daylight was lower on Farm A (69/285 (24%)) than Farm B (128/313 (41%)) (p = 0.001). Colt foals were less likely to be born during the day than fillies (OR = 0.63; (95% CI = 0.44-0.88); p = 0.008), but there was no effect of age or parity of mare or month of foaling (p>0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Mean gestation length of mares in this study was longer than that previously reported from other countries. Longer gestation length decreases the time available for these mares to get back into foal in the same season. It is important that managers take this into account and ensure optimum conditions for conception; breeding at the first postpartum oestrus may be essential. There were more mares foaling in daylight hours on one stud than has previously been reported. Under these conditions mares should be monitored for foaling during daytime as well as at night.

Exercise in Thoroughbred yearlings during sales preparation: a cohort study.

REASONS FOR PERFORMING STUDY: There is increasing evidence suggesting that early exercise in Thoroughbred racehorses may be beneficial to the development of the musculoskeletal system. At present, information on the exercise programmes and health problems of individual yearlings during a sales preparation is scant. OBJECTIVES: To describe the exercise and health problems of Thoroughbred yearlings during preparation for sales, and to identify variations in exercise between and within farms. METHODS: A prospective cohort study was used to collect exercise and health information from 18 farms across New Zealand. Daily exercise records for individual horses were recorded during the studfarms' preparation for the annual national yearling sales in January 2009. RESULTS: Data were collected from 319 yearlings, of which 283 (88.7%) were exercised (hand walking, mechanical walker and lungeing) during their preparations. Sales preparation lasted a median of 69 days (interquartile range 61-78) and differed significantly between farms (P<0.001). The median exercise time performed differed significantly by gender (P<0.001), farm (P<0.001) and month of the preparation (P<0.001), but not by type of sale (P = 0.14) or category of sales price (P = 0.12). Within certain farms, daily exercise differed between horses as did total exercise by gender and the number of days spent in the sales preparation. Lameness was the most common condition affecting yearlings and the overall incidence rate of lameness was 0.08 per 100 horse days (95% confidence interval 0.05-0.13). Incidence rates of lameness varied significantly between farms (P = 0.02), but not by age (P = 0.77), sales type (P = 0.58) or month of the preparation (P = 0.53). CONCLUSIONS AND POTENTIAL RELEVANCE: Yearling exercise programmes varied between and within farms. Since exercise is already being tailored for each individual horse, there may be an opportunity to allow for modifications to sales preparation with the future career in mind.

The relationship of training milestones with racing success in a population of Standardbred horses in New Zealand.

AIM: To investigate the association between attainment of training milestones by 2-year-old horses with racing outcomes in a population of Standardbred racehorses in New Zealand. METHODS: Retrospective records of the 2001/2002-born Standardbred foals were obtained. The three training milestones used were: registered with a trainer, entered in a trial, and competed in a race. The racing outcomes were length of career in years raced and number of race starts, and total earnings. Cox regression analysis was used to assess the association between attainment of the three milestones by 2-year-olds and the number of race starts and years raced. Logistic regression models were used to determine the association between attainment of the milestones by 2-year-olds and the outcomes won and placed in a race. Linear regression was used to model the association between attainment of the milestones by 2-year-olds and annual earnings and total earnings (transformed using Ln (earnings+NZ$100)). RESULTS: Of 3,032 horses in the population, 1,018 (33.6%) registered with a trainer, 609 (20.1%) trialled, and 272 (9.0%) raced as 2-year-olds. Horses that first raced as 2-year-olds had a longer racing career and more race starts than those that that did not race as 2-year-olds (p<0.001); this was also true when starts in the 2-year-olds were omitted from analyses. Horses that were registered with a trainer, trialled or raced as 2-year-olds were more likely to have won or placed in a race than those that did not achieve the milestones as 2-year-olds (p<0.001). Linear regression showed horses that trialled and raced as 2-year-olds had greater total earnings than those that did not, and male horses had a greater total earnings than female horses. CONCLUSION: Only one third the Standardbred racehorses born in 2001/2002 registered with a trainer as 2-year-olds, but the results of this study indicate that horses that began training, trialling, or racing as 2-year-olds had longer and more successful careers than those that did not achieve the milestones as 2-year-olds. Further investigation is required to quantify the management practices of these horses to determine the factors that may be associated with a successful racing career.

The use of allied health therapies on competition horses in the North Island of New Zealand.

AIM: To obtain data on the use of allied health therapy within competitive equestrian sport in the North Island of New Zealand. METHODS: Data were collected during January 2010 by survey at show jumping and dressage championships in the North Island, and from racing yards in the Central Districts of New Zealand. The survey consisted of 30 open, closed and multiple-choice questions, and was conducted face-to-face, by the same interviewer. Information on the demographics of riders or trainers and horses in each discipline (show jumping, dressage, and Thoroughbred racing), the use of allied health therapy (physiotherapy, chiropractic and equine sports massage) on horses, and knowledge of training and qualifications of the allied health therapists was obtained. Univariable and multivariable logistic regression were used to examine relationships between demographic variables and the use of allied health therapists. RESULTS: In total, 110 riders or trainers participated in the survey. The relative contribution of responses across disciplines was 39/110 (36%), 41/110 (37%) and 30/110 (27%) for show jumping, dressage, and Thoroughbred racing respectively. Allied health therapists were used by 68/110 (62%) respondents to treat their horses. The most common types of allied health therapy used were chiropractic (25/68; 37%) and physiotherapy (16/68; 24%). The main reasons for using allied health therapies were for back pain (22/68; 32%) and lameness (17/68; 25%). Only 5/68 (7%) respondents chose a type of allied health therapy based on veterinary advice, and 49/68 (72%) stated that their veterinarian and allied health therapist did not work together when treating their horses. The final multivariable model for use of allied health therapists included the explanatory variables discipline of the rider or trainer and the number of horses in training per season. CONCLUSIONS AND CLINICAL RELEVANCE: The use of allied health therapies for the treatment of competition and racehorses was widespread. Many riders or trainers perceived allied health therapy to be beneficial, however many therapists and veterinarians do not work together and therefore the integrative treatment approach to rehabilitation is lost.