Australian veterinarians who work with horses: an analysis

OBJECTIVE: To define and describe the population of Australian veterinarians who work with horses. METHOD: Questionnaires were mailed to 866 veterinarians who had been identified as working with horses, and 87% were completed and returned. Data were entered onto an Excel spreadsheet, and analysed using the SAS System for Windows. RESULTS: About 12% of Australia's veterinarians were doing all the veterinary work with horses, and about 3% worked exclusively (> 90%) with horses, but did more than half (58%) of the horse work. Veterinarians working with horses included more males (80%) than the veterinary population as a whole (approximately 60%). Males had an average age of 47 years, females 35. Almost all (94%) worked in private practice, with 31% being employees, 28% partners and 41% sole owners. Females were more likely to be employees than males. Males reported working 55 hours/week; females 49. More females (44%) than males (16%) had worked less than full-time for more than a year. Males expected to work for another 12 years in full-time equivalents, and females for 16. One quarter (24%) saw only horses, but treated 58% of total horse cases. One-half had < 25% horses, and 29% had < 10% of horses in their caseloads. More of the older (54% of those aged > 60) than younger respondents (27% of those < 40) had grown up on farms with animals. One-quarter (24%) decided to become a veterinarian while in primary school, and females decided at a younger age than males. Overall, younger respondents decided at a younger age than did their older counterparts. A veterinarian contributed to the decision for 21% of these veterinarians. CONCLUSION: In this survey, Australian veterinarians who work with horses were found to be typically male, and advanced in their careers. As these older veterinarians retire, there may not be enough veterinarians who are committed to and competent with horses to take their places.     

Cross-sectional study of antimicrobial-resistant bacteria in horses. Part 1: Prevalence of antimicrobial-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus

Reasons for performing study: The increasing prevalence of antimicrobial‐resistant bacteria such as methicillin‐resistant Staphylococcus aureus (MRSA) and antimicrobial‐resistant Escherichia coli represents a significant problem. However, the carriage of such bacteria by horses in the UK has not been well characterised. Objectives: To estimate the prevalence of nasal carriage of MRSA and faecal carriage of antimicrobial‐resistant E. coli amongst horses in the general equine community of the mainland UK. Methods: A cross‐sectional study of horses recruited by 65 randomly selected equine veterinary practices was conducted, with nasal swabs and faecal samples collected. Faecal samples were cultured for antimicrobial‐resistant E. coli. Nasal swabs were cultured for staphylococcal species; methicillin‐resistant isolates identified as S. aureus were characterised by SCCmec and spa gene typing. Multilevel logistic regression models were used to calculate prevalence estimates with adjustment for clustering at practice and premises levels. Spatial variation in risk of antimicrobial resistance was also examined. Results: In total, 650 faecal samples and 678 nasal swabs were collected from 692 horses located on 525 premises. The prevalence of faecal carriage of E. coli with resistance to any antimicrobial was 69.5% (95% CI 65.9–73.1%) and the prevalence of extended‐spectrum β‐lactamase (ESBL)‐producing E. coli was 6.3% (95% CI 4.1–9.6%). The prevalence of nasal carriage of MRSA was 0.6% (95% CI 0.2–1.5%). Spatial analysis indicated variation across the UK for risk of carriage of resistant and multidrug‐resistant (resistant to more than 3 antimicrobial classes) E. coli. Conclusions and potential relevance: Carriage of MRSA by horses in the community appears rare, but the prevalence of antimicrobial‐resistant E. coli (including ESBL‐producing E. coli) is higher. A high prevalence of antimicrobial‐resistant bacteria could have significant health implications for the horse population of the UK.     

Australian veterinarians who work with horses: attitudes to work and career

OBJECTIVE: To describe the attitudes to their work and career of those Australian veterinarians who work with horses. METHOD: Questionnaires were mailed to 866 veterinarians who had been identified as working with horses, and 87% were completed and returned. Data were entered onto Excel spreadsheets, and analysed using the SAS System for Windows. RESULTS: The main attractions of veterinary work with horses were the horses themselves and the equine industries, but working outdoors and with rewarding clients, and the satisfaction of successful outcomes were attractions for many. The list of disadvantages was longer, and included unreasonable and disagreeable clients as well as those who provided inadequate facilities, could not control their horses or did not care for them. The physical demands and risks of injury, the amount of time required, low rates of return and difficulties in collecting payment, were other major disadvantages. Some mentioned concerns about litigation, unethical behaviour, and recruiting and retaining veterinarians competent with horses. For many in mixed practice, the difficulties in affording modern equipment, and of developing and maintaining their own competence with horses, was a real concern. More than three-quarters of the respondents reported that their careers had lived up to expectations and that they would become veterinarians again; 70% of equine veterinarians would become an equine veterinarian again. Almost all (93%) of the respondents were either very glad, or 'generally glad though with some misgivings' that they had done the veterinary course. Older veterinarians reported suffering less stress, and being more content with their career, than younger colleagues. CONCLUSIONS: The advantages of doing veterinary work with horses outweigh the disadvantages for most veterinarians, especially those well advanced in their careers.     

Molecular characterization of community‐associated methicillin‐resistant Staphylococcus aureus from pet dogs

Community‐associated methicillin‐resistant Staphylococcus aureus (MRSA) is a serious public health concern and in Australia, one that disproportionately affects Aboriginal people. Paralleling MRSA in human medicine, methicillin‐resistant S. pseudintermedius (MRSP) is an increasingly prevalent pathogen in veterinary medicine. We aimed to characterize the carriage of MRSA and MRSP in dogs and cats from predominantly Aboriginal communities in a very remote region of New South Wales (NSW), Australia. Pets (303 dogs and 80 cats) were recruited from six communities in western NSW. Three swabs were collected from each animal (anterior nares, oropharynx and perineum) and from skin lesions or wounds (if present) and cultured on selective media for methicillin‐resistant staphylococci. Human host‐adapted community‐associated MRSA representing four multilocus sequence types (ST1‐IV, ST5‐IV, ST72‐IV, ST93‐IV) were isolated from eight dogs (prevalence 2.6%, 95% confidence interval 1.3%–5.1%). Two ST5‐IV isolates from a single dog were phenotypically trimethoprim‐resistant, harbouring trimethoprim‐resistant gene dfrG within the SCCmec type IVo mobile genetic element. MRSA was not isolated from any cats and MRSP was not isolated from any dogs or cats. This study estimated a high prevalence of human host‐adapted community‐associated MRSA carriage in dogs despite an absence of MRSP. This suggests MRSA carried by dogs in remote NSW originate from human hosts. The cycle of transmission between people, dogs and common environmental sources warrants further investigation. To our knowledge, this is the first report of trimethoprim‐resistant ST5‐IV in eastern Australia and the first report of trimethoprim‐resistant ST5‐IV from a dog.     

Epidemiological Analysis of Methicillin-Resistant Staphylococcus aureus Carriage among Veterinary Staff of Companion Animals in Japan

Veterinary staff carrying methicillin-resistant Staphylococcus aureus(MRSA) can be a source of MRSA infection in animals. To identify risk factors of MRSA carriage among veterinary staff, MRSA carriage and epidemiological information (sex, career, contact with MRSA-identified animal patients and others) were analyzed from 96 veterinarians and 70 veterinary technicians working at 71 private veterinary clinics in Japan. Univariate analysis determined sex (percentage of MRSA carriage, male (29.2%) vs. female (10%); P=0.002) and career (veterinarians (22.9%) vs. veterinary technicians (10%); P=0.030) as risk factors. Multivariable analysis revealed that sex was independently associated with MRSA carriage (adjusted odds ratio, 3.717; 95% confidence interval, 1.555–8.889; P=0.003). Therefore, male veterinary staff had a higher risk of MRSA carriage than female staff.     

Low prevalence of zoonotic multidrug‐resistant bacteria in veterinarians in a country with prudent use of antimicrobials in animals

The occurrence of multidrug‐resistant zoonotic bacteria in animals has been increasing worldwide. Working in close contact with livestock increases the risk of carriage of these bacteria. We investigated the occurrence of extended‐spectrum beta‐lactamase (ESBL) and plasmidic AmpC beta‐lactamase producing Enterobacteriaceae (ESBL/pAmpC‐PE) and livestock‐associated methicillin‐resistant Staphylococcus aureus (LA‐MRSA) in Finnish veterinarians (n = 320). In addition to microbiological samples, background information was collected. Bacterial whole genome sequencing was performed to deduce sequence types (STs), spa types and resistance genes of the isolates. In total, 3.0% (9/297) of the veterinarians carried ESBL producing Escherichia coli, with one ESBL producing E. coli isolate producing also AmpC. Seven different STs, sequences of several different plasmid groups as well as several different bla_ESBL/pAmpC genes existed in different combinations. No carbapenemase or colistin resistance genes were detected. MRSA was detected in 0.3% (1/320) of the samples. The strain belonged to LA‐MRSA clonal complex (CC) 398 (ST398, spa type 011, lacking Panton‐Valentine leukocidin genes). In conclusion, this study shows low carriage of multidrug‐resistant zoonotic bacteria in Finnish veterinarians. However, finding LA‐MRSA for the first time in a sample from a veterinarian in a country with prudent use of animal antimicrobials and regarding the recent rise of LA‐MRSA on Finnish pig farms, a strong recommendation to protect people working in close contact with animals carrying LA‐MRSA CC398 is given. Further studies are needed to explain why the prevalence of LA‐MRSA in veterinarians is lower in Finland than in other European countries.     

Methicillin-resistant Staphylococcus aureus in a population of horses in Australia

Objective To evaluate if methicillin‐resistant Staphylococcus aureus (MRSA) is present in the horse population in Australia. Design A two‐part retrospective study of laboratory submissions of microbial culture results from horses. Methods Part A: medical records of 216 horses that had MRSA screening performed on nasal swabs collected over a 30‐day period at admission to the Scone Equine Hospital Clovelly Intensive Care Unit were retrieved. Part B: laboratory records from 2004 to 2009 of culture submissions to the Scone Veterinary Laboratory were reviewed and cultures that grew MRSA were identified. The MRSA isolates from Parts A and B were genotyped over an 18‐month period. Results MRSA screening of 216 horses identified eight (3.7%) positive samples. MRSA was isolated from cultures of 80 (0.002%) clinical bacteriology samples over a 6‐year period. Genotypic analysis was performed on 36 isolates. All MRSA characterised had the same pulse field gel electrophoresis pattern (type 1), with eight closely related subtypes identified (subtypes A–F and H) and 66% of isolates classified as subtype D, which multilocus sequence and staphylococcal cassette chromosome mec typing analysis identified as ST612‐MRSA‐IVa, a clonal complex (CC) 8 S. aureus strain. Antimicrobial resistance to more than two classes of antimicrobials was common. Conclusions MRSA was present in a population of horses in Australia. Genotypic analysis of the isolates identified the MRSA strain as CC8 S. aureus. Further research needs to be undertaken to evaluate MRSA infection and colonisation of horses and personnel in Australia.     

Issues associated with the application to veterinarians of a mailed questionnaire regarding lower respiratory-tract disease in racehorses

This study evaluated a questionnaire investigating the attitudes and behaviours of veterinarians regarding the cause, diagnosis and treatment of lower respiratory-tract disease in racehorses. The questionnaire was sent to all non-student members (648) of the Australian Equine Veterinary Association: two mailings and a single telephone contact (each separated by four weeks). Subsequent phases were only administered to those who had not responded to earlier phases. In total, 467 (72.1%) of the 648 mailed questionnaires were returned. Of these, 354 were usable. The remaining 113 respondents gave various reasons for not completing the questionnaire; the most common (68%) was that horses were not a component of their practice. Those respondents working primarily with horses required fewer phases to return the questionnaire. Although deviating from previously described questionnaire designs, the described protocol provided a reasonable response rate.     

Survey of equine castration techniques,preferences and outcomes among Australian veterinarians

Objectives

(1) To collect the perceptions of veterinarians performing equine castrations in Australia on techniques, preferences and outcomes, (2) to investigate veterinarian use and experience with the Henderson castrating instrument and (3) to investigate potential associations between demographics, castration methods and techniques, and complications.

Design

Online survey of members of the Australian Veterinary Association’s Special Interest Group, Equine Veterinarians Australia (EVA).

Methods

A link to the survey was included in the EVA e‐newsletter and practices on the EVA website were contacted by telephone and follow‐up email. Fisher’s exact test was used to determine associations between ligation and complications. A generalised linear model with a negative binomial family was used to determine associations between count response variables and categorical independent variables.

Results

Responses were obtained from 138 veterinarians (response rate, 13.1%) who performed 5330 castrations over 12 months. Castrations were most commonly performed in the field, on anaesthetised horses, using emasculators, via an open approach and without ligation of the spermatic cord. Estimated complications after use of emasculators were swelling (25%), haemorrhage (5%) and infection (5%). The Henderson instrument was used by approximately 10% of respondents and its use for castration was associated with fewer reports of postoperative swelling compared with emasculators (P = 0.002). Rates of evisceration with the Henderson and emasculator methods were comparable (0.43% and 0.9%, respectively).

Conclusion

Castration preferences varied widely among survey participants. Reported complication types and rates were comparable to those reported previously in other countries. Perceptions that the Henderson instrument was associated with less swelling should be investigated further via a prospective controlled investigation.     

A survey of the risk of zoonoses for veterinarians

The objectives of this study were to identify factors associated with zoonotic infections in veterinarians, the incidence of physician consultation and treatment and the incidence of diagnostic and treatment errors. Veterinarians in any area of practice were solicited to participate in an online survey through an invitation letter sent to the Oregon Veterinary Medical Association. Proportions of respondents to various factors were analyzed for differences among gender, age, time since graduation and type of practice in which they worked. In all, 216 complete responses were received. In all, 13.9% of respondents had never been vaccinated against rabies, and 20.8% had been exposed to suspect rabid animals, mostly (64.4%) a single time. Other zoonoses were reported by 47.2% of respondents: mostly diseases transmitted via contact (57.4%) especially ringworm, followed by those with oral transmission (21.7%). Most zoonotic infections were reportedly acquired by young veterinarians working in primary care veterinary practice. Cats were the species most commonly reported as the animal source of a zoonotic infection. Veterinarians likely self-diagnosed zoonotic diseases, especially those transmitted by contact. Medical care providers were consulted for diagnosis of more serious diseases. Diagnosis and treatment errors were uncommon. Results of this study emphasize the need to educate future veterinarians during their early years in veterinary school about the risks associated with their future jobs.     

Occupational health hazards in veterinary medicine: physical, psychological, and chemical hazards

This paper reports physical, psychological, and chemical hazards relevant to western Canadian veterinarians as obtained by a self-administered mailed questionnaire. Nine-three percent (750/806) of veterinarians reported some form of injury during the previous 5 years; 17% of respondents (131/791) indicated injuries that resulted in 1 or more days off work. Median stress levels were similar across work environments; overall, 7% (57/813) indicated either no stress or severe stress, while 53% (428/813) indicated moderate stress. Twenty percent (3/15) of food animal practitioners and 37% (114/308) of companion animal practitioners who took X-rays reported accidental exposure. Accidental exposure to gas anesthetic was reported by 69% (394/570) of those in private practice. Exposure to chemicals occurred in all work environments. Veterinarians in western Canada are at risk of minor to severe injury due to both animal and non-animal related causes.     

Disease and injury among veterinarians

OBJECTIVE: To identify occupational causes of disease and injury in veterinarians and their staff. DESIGN: A self-administered questionnaire was mailed to all of the 160 registered veterinary practices in Western Australia. RESULTS: Injuries accounted for most workers' compensation claims over a 12-month period with 31% of respondents losing a total of 360 work days with a mean of 13.3 days whereas non-occupational diseases such as influenza accounted for 408 work days lost. Over a 10-year period, 71% of respondents had been injured. The major physical injuries were dog and cat bites, cat scratches, scalpel blade cuts and back injuries from lifting heavy animals. Exposure to chemicals such as flea rinses, formalin, glutaraldehyde, x-ray developers and gaseous anaesthetics were reported to cause headache, nausea and allergies. Thirty percent of respondents did not have extractor fans for scavenging waste anaesthetic gases. The study showed high use of radiography (94%) for diagnostic purposes with 24% of respondents believing radiation exposure is a major occupational health and safety issue. Stress, drug abuse, suicide and burglary were also reported. Despite a high awareness of zoonotic diseases, there were very few reports of these. CONCLUSION: Injuries and other occupational hazards reported together with work days lost demonstrate a need for improving the working environment of veterinarians and their staff and the development of comprehensive health and safety programs.     

Occupational swine exposure and Hepatitis E virus,Leptospira, Ascaris suum seropositivity and MRSA colonization in Austrian veterinarians, 2017–2018—A cross‐sectional study

We investigated the prevalence of Hepatitis E Virus (HEV), Leptospira and Ascaris suum (A. suum) seropositivity, and of nasal methicillin‐resistant Staphylococcus aureus (MRSA) colonization among Austrian practising veterinarians, and assessed the association with occupational swine livestock exposure. The 261 participants completed a questionnaire on demographics, intensity of occupational swine livestock contact and glove use during handling animals and their secretions. Participants' blood samples were tested for HEV, Leptospira and A. suum seropositivity and nasal swabs cultured for MRSA. We compared swine veterinarians (defined as >3 swine livestock visits/week) to non‐swine veterinarians (≤3 swine livestock visits/week) with regard to the outcomes through calculating prevalence ratio (PR) and 95% confidence interval (CI). Furthermore, the relationship between occupational swine livestock contact and the study outcomes was examined by age (</≥55 years) and glove usage. The prevalence of nasal MRSA colonization was 13.4% (95% CI: 9.3–17.6), of HEV seropositivity 20.8% (95% CI: 15.8–25.7) and A. suum seropositivity 44% (95% CI: 37.7–50.2). The highest anti‐leptospiral antibodies titres were 1:200 (L. hebdomadis) and 1:100 (L. autumnalis, L. caicola) found in three non‐swine veterinarians. Compared to non‐swine veterinarians, swine veterinarians were 1.9 (95% CI: 1.0–3.4) and 1.5 (95%CI: 1.0–2.3) times more likely HEV seropositive and A. suum seropositive, respectively, and 4.8 (95%CI: 2.5; 9.3) times more likely nasally colonized with MRSA. Among glove‐using veterinarians, occupational swine contact was no longer a determinant for HEV seropositivity (PR 1.6; 95% CI: 0.8–2.9). Similar was found for A. suum seropositivity, which was no longer associated with occupational swine livestock contact in the subgroup of glove using, ≥55‐year‐old veterinarians (PR: 1.07; 95% CI: 0.4–3.3). Our findings indicate that >3 occupational swine livestock visits per week is associated with HEV and A. suum seropositivity and nasal MRSA colonization and that glove use may play a putative preventive role in acquiring HEV and A. suum. Further analytical epidemiological studies have to prove the causality of these associations.     

Current joint therapy usage in equine practice: a survey of veterinarians 2009

Reasons for performing study: Medications are frequently employed to treat intra‐articular (IA) problems in the performance horse. Actual usage of the different IA medications in horses is not available. Objectives: To determine the most common usage of these medications, members of the American Association of Equine Practitioners (AAEP) were surveyed. Methods: An email link to an online survey was electronically sent to 6305 AAEP members and the responses tabulated and analysed with a logistic regression model. Results: A total of 831 survey responses were submitted and tabulated. Eighty per cent of the respondents indicated that they see 100% equine cases in their practice. The majority of respondents (77%) use triamcinolone acetonide (TA) to treat high motion joints and 73% use methylprednisolone acetate (MPA) to treat low motion joints. Veterinarians treating the Western performance and Sport horse were significantly more likely to use TA in high motion joints compared to MPA (P = 0.0201 and P<0.0001, respectively). Triamcinolone acetonide use compared to MPA in high motion joints by racehorse veterinarians was significantly lower compared to other veterinarians (P<0.0001). Polysulphated glycosaminoglycan (Adequan) and hyaluronate sodium (Legend) were the most commonly used disease modifying products (63 and 57% of respondents, respectively). Sport horse practitioners were significantly more likely than race or show horse veterinarians to utilise IRAP products (P = 0.0035 and P = 0.04, respectively). Respondents who had been in practice for more than 10 years were significantly less likely to use antimicrobials in their joint injections compared to those in practice for less than 10 years (P<0.0001). Conclusions: Significant differences existed in usage of medications related to primary discipline treated and years practicing. Potential relevance: The results of this study aid in defining the current usage of different joint therapy medications within equine practice. This knowledge can guide further research as well as education.     

A review of the characteristics and treatment of methicillin‐resistant Staphylococcus aureus (MRSA) in the horse and a case series of MRSA infection in four horses

Methicillin‐resistant Staphylococcus aureus (MRSA) is an emerging cause of serious bacterial infection in the horse, with an increasing number of cases reported over the last decade. MRSA, along with other commensal staphylococcal species, can reside on the mucosa of several sites in the horse, particularly the nose. Nasal carriage of MRSA appears rare amongst horses in the community, although a higher prevalence has been found in hospitalised horses. MRSA infections can involve a variety of body sites, but most commonly encountered are soft tissue infections of either traumatic or surgical wounds. MRSA strain types isolated from horses are typically multidrug‐resistant and usually differ from those recovered from humans and other small animal species. Treatment of infection can be prolonged and is dependent on timely, accurate diagnosis and on appropriate therapy; often guided by antimicrobial susceptibility testing. The purpose of this review is to provide clinically relevant information for the equine practitioner and, for illustration, the diagnosis, treatment and outcome of 4 clinical cases of MRSA infection in horses is discussed.     

Prevalence of occupational exposures and protective practices in Australian female veterinarians

OBJECTIVE: To identify the prevalence of exposure to potentially harmful occupational hazards in Australian female veterinarians and to report factors associated with prevalence of occupational hazards in this profession. DESIGN: National cross-sectional survey of a cohort population. PROCEDURE: A self-administered questionnaire was mailed to 5748 veterinarians (males and females) graduating from Australian veterinary schools from 1960 to 2000. This paper reports the prevalence of occupational exposures in 1197 female veterinarians in their current job including radiation, anaesthetic gases, pesticides and long working hours. Comparisons were undertaken between respondents by practice type and decades of graduation. Multivariate logistic regression was undertaken to predict the risk for exposure to occupational hazards in female veterinarians by age, type of practice, graduation year and number of hours worked. RESULTS: The response rate for females was 59%. We found that age under 30 years, small and mixed animal practice, graduation year after 1990, and working more than 45 hours per week were all associated with greater exposure to putative risk factors. Mixed animal practitioners worked more than 45 hours per week (53%) and reported the highest exposure to anaesthetic gases (94%) and pesticides (54%). Twenty two percent of those who were exposed to anaesthetic gases did not have waste anaesthetic gas scavenging systems. Small animal practitioners reported they took more X-rays (90%). While taking X-rays, 56% of respondents reported physically restraining animals, and only one in five of respondents used film holders and lead screens. CONCLUSIONS: The high prevalence of potentially harmful exposures among female veterinarians and lack of use of protective equipment at work needs to be considered in developing and planning the safety of veterinary work.     

Methicillin‐resistant Staphylococcus aureus in urban Norway rat (Rattus norvegicus) populations: Epidemiology and the impacts of kill‐trapping

Urban Norway rat (Rattus norvegicus) populations can carry the bacteria methicillin‐resistant Staphylococcus aureus (MRSA). There are numerous knowledge gaps in the epidemiology of MRSA in these populations that limit understanding of its ecology in urban environments. For example, fecal shedding of MRSA, which may increase environmental contamination, has been reported in other species; however, it is unknown whether Norway rats carry the bacteria rectally. Furthermore, while intermittent MRSA shedding has been shown in other species and may dictate when the risk of transmission is highest, duration of carriage has not been examined for Norway rats. Previous work has shown that lethal animal‐control methods may increase the level of pathogens within reservoir populations, possibly by disrupting ecological patterns. However, the impact of rodent‐control on potentially environmentally acquired pathogens like MRSA has not been tested. Using capture‐mark‐recapture methods in an inner‐city neighborhood in Vancouver, Canada, we show that rats intermittently carry MRSA both in the rectum and oropharynx. By assessing the prevalence of MRSA before and after enacting a pest‐control intervention, we report that kill‐trapping had no impact on the prevalence of carriage of this environmentally‐acquired agent.     

A questionnaire study on parasite control practices on UK breeding Thoroughbred studs

Reasons for performing study: Improved education of veterinarians and equine owners/managers is essential in implementing parasite control strategies that are less reliant on chemicals. Methods: This questionnaire study, conducted on 61 UK Thoroughbred (TB) establishments during 2009 and 2010, was designed to obtain an understanding of current helminth control practices on studs. To our knowledge, this is the first occasion that statements obtained from TB studs via questionnaire have been supported by statistical analysis. Results: Despite many respondents indicating high levels of concern regarding anthelmintic resistance, 56% of these establishments that received visiting equines co‐grazed these animals with permanent stock and <74% administered anthelmintics prior to integration. In the 12 months preceding the study, most respondents administered frequent macrocyclic lactone (ML) treatments, with none appearing to leave any animals in groups untreated at each administration. Indiscriminate whole group treatments with MLs and movement of animals to ‘clean grazing’ post treatment (reported by >25% of respondents), indicates that many stud owners/managers are not aware of the strong risk factors for the development of anthelmintic resistance. Few studs had conducted faecal egg count (FEC) analysis in the past and only 22% indicated that they considered this form of analysis beneficial in determining anthelmintic choice. Conclusions and potential relevance: The challenge now is to convince stud owners/managers to deviate from their current practices to control strategies that are more likely to preserve anthelmintic efficacy. Veterinarians need to get more involved in implementing these control strategies, with better emphasis placed on the role of diagnostic tests in facilitating targeted treatments and in investigating anthelmintic sensitivity in the associated nematode populations.     

Incidence of major injuries, severe colic, and acute laminitis at American Horse Shows Association A- and B-rated shows

A questionnaire was designed to determine the incidence of major injuries, severe colic, and acute laminitis in horses at American Horse Shows Association (AHSA) A- and B-rated shows, ie, those shows requiring a veterinarian in attendance. The questionnaire was sent to the show stewards and filled out by the attending veterinarians of the AHSA A- and B-rated shows held from January 1982 to October 1984. Of 2,952 questionnaires sent out, 799 (27%) were completed and returned by veterinarians; 99 of them were discarded because of incomplete or misleading information. The study revealed a low incidence of major injuries, severe colic, and acute laminitis in horses at AHSA A- and B-rated shows. In 700 horse shows surveyed, there was a total of 231 major injuries, severe colic, or acute laminitis. Considering that the shows surveyed had a median number of 193 horses and a median duration of 3 days, the 231 injuries represent a relatively small number, compared with the general population at risk.     

Community-associated methicillin-resistant Staphylococcus aureus in horses and humans who work with horses

OBJECTIVE: To evaluate the prevalence of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) in horses and horse personnel. DESIGN: Prospective prevalence study. SAMPLE POPULATION: 972 horses and 107 personnel from equine farms in Ontario, Canada and New York state. PROCEDURE: Nasal swab specimens were collected from horses and humans on farms with (targeted surveillance) and without (nontargeted surveillance) a history of MRSA colonization or infection in horses during the preceding year. Selective culture for MRSA was performed. Isolates were typed via pulsed-field gel electrophoresis, and antibiograms were determined. RESULTS: MRSA was isolated from 46 of 972 (4.7%) horses (0/581 via nontargeted surveillance and 46/391 [12%] via targeted surveillance). Similarly, MRSA was isolated from 14 of 107 (13%) humans (2/41 [5%] from nontargeted surveillance and 12/66 [18%] from targeted surveillance). All isolates were subtypes of Canadian epidemic MRSA-5, an uncommon strain in humans. All isolates were resistant to at least 1 antimicrobial class in addition to beta-lactams. On all farms with colonized horses, at least 1 human was colonized with an indistinguishable subtype. For horses, residing on a farm that housed > 20 horses was the only factor significantly associated with MRSA colonization. For humans, regular contact with > 20 horses was the only identified risk factor. CONCLUSIONS AND CLINICAL RELEVANCE: Results confirm a reservoir of colonized horses on a variety of farms in Ontario and New York and provide evidence that 1 MRSA strain is predominantly involved in MRSA colonization in horses and humans that work with horses.