First Report of Methicillin-Resistant Staphylococcus aureus ST5 and ST398 from Purebred Lusitano Horses

Methicillin-resistant Staphylococcus aureus (MRSA) was first described in horses in 1996. The frequency of MRSA colonization in horses varies among European countries, but it is unknown in Portugal. The aim of this study was to screen for MRSA nasal carriage in a sample of horses entering the Equine Unit, Large Animal Veterinary Teaching Hospital of the Faculty of Veterinary Medicine, Lisbon, Portugal. Seventy-one horses were swabbed, and MRSA was identified by selective isolation on a chromogenic medium. Two S aureus isolates showed resistance to oxacillin (minimum inhibitory concentration >4 μg/mL) and contained the mecA gene. Both strains were isolated from purebred Lusitano horses that lived in farms with more than 20 equines. These MRSA strains represented two different clones: isolate FMVA3/10 was an MRSA sequence type ST5 with a staphylococcal cassette chromosome mec VI, coresistant to erythromycin and clindamycin; and isolate FMVA16/10 was sequence type ST398, with a staphylococcal cassette chromosome mec IV, coresistant to tetracycline, gentamicin, and trimethoprim. Isolate FMVA3/10 represents a human epidemic clone not previously reported among horses in Europe, which once again reinforces the fact that transmission of MRSA clones between horses and humans occurs. Isolate FMVA16/10 represents the first report of the detection of MRSA ST398 among horses in Portugal. Lusitano horses can carry animal and human MRSA in the nostrils, acting as reservoirs, which can potentially be transmitted to humans.     

High occurrence of methicillin-resistant Staphylococcus aureus ST398 in equine nasal samples

Methicillin-resistant Staphylococcus aureus (MRSA) infections do occur in equine patients. Little is known, however, about their origin and the general equine MRSA colonization status. In West European horses in particular, neither the colonization rate nor the present strains or their antimicrobial susceptibility patterns are known. In the present study, a sample of 110 (Belgian, French, Dutch and Luxemburg) horses presented at a Belgian equine clinic was screened for nasal MRSA carriage. An indirect culturing protocol using a 0.001% colistin and nalidixic acid containing broth was compared to a direct agar method. Phenotypic identification following growth on a chromogenic MRSA screening agar (ChromID MRSA) was combined with genotypic analysis (PCR, PFGE, SCCmec, spa, and MLST typing). Antimicrobial susceptibility was tested through disk diffusion. Twelve (10.9%) horses carried MRSA, with the enrichment protocol resulting in a significantly higher isolation rate. None of the isolated strains were typeable through SmaI PFGE. They all harboured SCCmec type IVa or V and belonged to spa type t011 or t1451 of the ST398 lineage. All isolates were tetracycline resistant and sulfonamide and enrofloxacin susceptible. Macrolide, lincosamide, trimethoprim and aminoglycoside susceptibility varied and in total five different antimicrobial resistance patterns were distinguished. These results show that ST398 is certainly present in West European horses. Due to its known interspecies transmission and the structure of the equine industry, the presence of this clone in horses poses a substantial health hazard for both animals and humans.     

Methicillin-resistant Staphylococcus aureus in a neonatal alpaca

A 6-hour-old alpaca was presented for evaluation of respiratory difficulty. As part of routine surveillance, methicillin-resistant Staphylococcus aureus (MRSA) was identified from a nasal swab taken upon admission to the hospital. No signs of MRSA infection were noted. The MRSA strain recovered was a human epidemic clone that has been associated with horses. Methicillin-resistant S. aureus colonization can occur in camelids, and the potential animal and public health risks require consideration.     

Methicillin-resistant Staphylococcus aureus in horses at a veterinary teaching hospital: frequency, characterization, and association with clinical disease

Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging equine pathogen. To attempt to control nosocomial and zoonotic transmission, an MRSA screening program was established for all horses admitted to the Ontario Veterinary College Veterinary Teaching Hospital, whereby nasal screening swabs were collected at admission, weekly during hospitalization, and at discharge. MRSA was isolated from 120 (5.3%) of 2,283 horses: 61 (50.8%) at the time of admission, 53 (44.2%) during hospitalization, and 6 from which the origin was unclear because an admission swab had not been collected. Clinical infections attributable to MRSA were present or developed in 14 (11.7%) of 120 horses. The overall rate of community-associated colonization was 27 per 1,000 admissions. Horses colonized at admission were more likely to develop clinical MRSA infection than those not colonized at admission (OR 38.9, 95% CI 9.49 160, P < 0.0001). The overall nosocomial MRSA colonization incidence rate was 23 per 1,000 admissions. The incidence rate of nosocomial MRSA infection was at the rate of 1.8 per 1,000 admissions, with an incidence density of 0.88 per 1,000 patient days. Administration of ceftiofur or aminoglycosides during hospitalization was the only risk factor associated with nosocomial MRSA colonization. MRSA screening of horses admitted to a veterinary hospital was useful for identification of community-associated and nosocomial colonization and infection, and for monitoring of infection control practices.     

Feedtrough dirt as a source of Clostridium botulinum type C intoxication in a group of farm horses

Four horses from the same farm developed clinical signs of botulism during the winter months; three of these horses died. One horse survived an initial attack and recovered over a three-week period, but died during a second attack. The horse that survived took six weeks to recover. Clinical and postmortem examination ruled out other causes of disease. Confirmation of the diagnosis was made by isolation of Clostridium botulinum type C toxin from the dirt in the bottom of an oak feedtrough used by all horses, and from the colonic contents of one of the horses that died. To our knowledge, this is the second case of C. botulinum type C intoxication reported in horses in North America. In both cases, soil and sand near aquatic environments were identified as the source of toxin.     

Whole genome sequencing of methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolated from 4 horses in a veterinary teaching hospital and its ambulatory service

Genomic characterization was conducted on 2 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from 2 horses hospitalized during an overlapping period of time and 2 methicillin-sensitive S. aureus (MSSA) strains isolated from 2 distinct horses. Phylogenetic proximity was traced and the genotypic and phenotypic characteristics of the antimicrobial resistance of the strains were compared.Whole genome sequencing of MRSA strains for this report was similar but differed from whole genome sequencing of MSSA strains. The MRSA strains were closely related, belonging to sequence type (ST) 612, spa type t1257, and SCCmec type IVd2B. The MSSA strains were also closely related, belonging to ST1660, spa type t3043, and having no detectable staphylococcal cassette chromosome mec elements. All MSRA and MSSA strains were Panton-Valentine leukocidin negative. There were discrepancies in the genotypic analysis and the antimicrobial susceptibility testing (phenotypic analysis) of MRSA strains for rifampin, trimethoprim-sulfamethoxazole, gentamicin, amikacin, and enrofloxacin.     

The first nosocomial outbreak of methicillin-resistant Staphylococcus aureus in horses in Sweden

Background

Methicillin-resistant Staphylococcus aureus (MRSA) in animals is a rare finding in Sweden. In horses, MRSA was first detected in a screening survey in 2007. In 2008, six clinical cases occurred in an equine hospital, indicating an outbreak.

Method

All MRSA isolates detected, 11 spa-type t011 and one t064 (n = 12), in infected horses (n = 10) and screening of horses (n = 2) in Sweden from December 2007 to March 2010 were retrospectively analysed with pulsed-field gel electrophoresis (PFGE) using Cfr9I and ApaI restriction enzymes, to study relationship between the isolates. Medical records of infected horses and outbreak investigation notes were scrutinised to monitor the clinical outcome and other aspects of the outbreak.

Results

Eight of the 10 infected horses were linked to one equine hospital and two to another hospital in the same region. The six horses infected with MRSA in 2008 underwent surgery during the period 22 May-7 July in one of the hospitals. Four more infections linked to the two hospitals were notified between 2009 and March 2010.Nine of the 11 spa-type t011 isolates had identical Cfr9I and ApaI PFGE pattern. All six infected horses from 2008 presented with this MRSA. Two t011 isolates differed in one and two bands, respectively, in PFGE.Nine horses suffered from surgical site infections (SSI). No antimicrobials were used following the MRSA diagnosis and the infections cleared. The time from surgery to MRSA diagnosis differed greatly between the horses (range 15-52 days).

Conclusions

Association in time and space of six horses infected with an identical MRSA strain of spa-type t011 confirmed an outbreak. Two isolates found in 2009 and 2010 in the outbreak hospital were closely related to the outbreak strain, indicating one circulating strain. Both spa-type t011 and t064 have been reported in horses in Europe prior to these findings. The observation that the infections cleared although antimicrobials were not used is encouraging for future prudent use of antimicrobials. The time from surgery to bacteriological diagnosis was not acceptable in most cases, as contagious spread was a risk. Sampling when symptoms of infection are noticed and accurate analysis are thus important.     

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.     

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.     

Methicillin-resistant Staphylococcus aureus (MRSA) on the skin of long-term hospitalised horses

Given the significance of methicillin-resistant Staphylococcus aureus (MRSA) infections for both horses and staff in equine veterinary hospitals, protocols are required to minimise the risk of nosocomial transmission, including the screening of the skin and nasal chambers of equine patients for evidence of infection. The objective of this study was to clarify the potential existence and extent of MRSA on the skin of horses requiring long-term hospitalisation (?6months). Thirty such horses were sampled at eight different locations on their skin and from their nasal chambers. MRSA was isolated from 12 animals (40%), with all sample sites testing positive on at least one occasion. Organisms were most frequently detected in the nasal chambers (relative sensitivity, 83.3%; 34.5% positive horses; isolation rate 33.3%). Skin presence was found in 30% of animals with the highest isolation rates found at the carpus (16.7%), neck, withers and croup (13.3% each). To achieve a relative screening sensitivity of >90%, at least one skin site was required in addition to nasal sampling. This evidence of skin as well as nasal reservoirs of MRSA in long-term hospitalised horses should facilitate the design of effective screening and containment protocols.     

Molecular epidemiology of environmental MRSA at an equine teaching hospital: introduction,circulation and maintenance

The role that environmental contamination might play as a reservoir and a possible source of Methicillin-resistant Staphylococcus aureus (MRSA) for patients and personnel at equine veterinary hospitals remains undefined, as the environment has only been monitored during outbreaks or for short periods. Therefore, the objectives of this study were to determine the monthly presence, distribution, and characteristics of environmental MRSA at an equine hospital, and to establish patterns of contamination over time using molecular epidemiological analyses. For this purpose, a yearlong active MRSA surveillance was performed targeting the environment and incoming patients. Antimicrobial susceptibility testing, SCCmec typing, PFGE typing, and dendrographic analysis were used to characterize and analyze these isolates. Overall, 8.6% of the surfaces and 5.8% of the horses sampled were positive for MRSA. The most common contaminated surfaces were: computers, feed-water buckets, and surgery tables-mats. Ninety percent of the isolates carried SCCmec type IV, and 62.0% were classified as USA500. Molecular analysis showed that new pulsotypes were constantly introduced into the hospital throughout the year. However, maintenance of strains in the environment was also observed when unique clones were detected for 2 consecutive months on the same surfaces. Additionally, pulsotypes were circulating throughout several areas and different contact surfaces of the hospital. Based on these results, it is evident that MRSA is constantly introduced and frequently found in the equine hospital environment, and that some contact surfaces could act as “hot-spots”. These contaminated surfaces should be actively targeted for strict cleaning and disinfection as well as regular monitoring.     

Identification and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from Austrian companion animals and horses

The aim of this study was to investigate the antimicrobial resistance, resistance gene patterns and genetic relatedness of a collection of Austrian methicillin-resistant Staphylococcus aureus (MRSA) isolates from companion animals and horses.A total of 89 non-repetitive MRSA isolates collected during routine veterinary microbiological examinations from April 2004 to the end of 2012, and one isolate from 2013 were used for this study. The presence of mecA and other resistance genes was confirmed by PCR. Isolates were genotyped by spa typing, two multiple-locus variable-number tandem repeat analyses (MLVA) analyses, SCCmec typing and multilocus sequence typing (MLST). PCR targeting Panton-Valentine leukocidin (PVL) and detection of staphylococcal enterotoxins (SE), toxic shock syndrome toxin (TSST) was performed using PCR assays. Antimicrobial susceptibility testing was performed.Five sequence types (STs—ST398, ST254, ST22, ST5 and ST1), SCCmec types II, IVa, V, and non-type-abele, 8 spa-types (t003, t011, t036, t127, t386, t1348, and t4450), and two isolates could not be assigned, 21 MLVA-14Orsay types Multiplex-PCR MLVA (mMLVA) displayed 17 different MLVA types.The present study is the most comprehensive dealing with MRSA from Austrian companion animals and horses. The results confirm that MRSA ST398 is present in a wide range of animal species and is predominant especially in horses. In other companion animals it is unclear whether the infections with the different MRSA isolates investigated in the present study truly represents a rare phenomenon or may be an emerging problem in companion animals.     

Methicillin-resistant Staphylococcus aureus (MRSA) contamination of retail pork

Recent reports of isolation of methicillin-resistant Staphylococcus aureus (MRSA) from food animals have raised concern about the potential for foodborne transmission. This study evaluated the prevalence of MRSA contamination of retail pork from 4 Canadian provinces. Methicillin-resistant Staphylococcus aureus was isolated from 31/402 [7.7%, 95% confidence interval (CI): 5.5% to 10.7%] of samples. Adjusted for clustering at the provincial level, the prevalence was 5.8% (95% CI% 2.2% to 14.4%). The most common clone was Canadian epidemic MRSA (CMRSA)-5 (12/31, 39%), which has been widely identified in horses and horse personnel, but not in pigs. Ten of the 31 (32%) isolates were nontypable by pulsed-field gel electrophoresis (PFGE) and belonged to spa 539/t034, a clone that is associated with food animals internationally. Nine (29%) isolates were CMRSA-2, a common human epidemic clone that has been found in pigs in Canada. While the relevance of contamination of retail meat is currently unclear, further study is required to determine if food may be a source of infection.     

Leptospirosis: An important infectious disease in North American horses

North American horses are commonly exposed to Leptospira organisms. Leptospira Bratislava is the most common infecting serovar but this serovar has not been confirmed to cause clinical disease in North American horses. Leptospira Pomona type kennewicki is responsible for most of the clinical diseases (leptospirosis) in North American horses. Leptospirosis is most commonly associated with diseases of the placenta and fetus, the kidneys and the eyes in horses. In-utero infections in pregnant mares may result in abortion, neonatal illness or birth of an antibody positive healthy foal. Acute renal failure in younger horses and recurrent uveitis in adult horses are other well documented clinical syndromes of leptospirosis. Abortions, neonatal disease and acute renal failure are caused by a subacute infection, while horses with Leptospira associated recurrent uveitis develop ocular disease months or years after the initial Leptospira infection. Diagnosis of Leptospirosis is made by a combination of antigen or antibody testing methods. Mares that abort following Leptospira infection have no additional clinical signs at the time of abortion but may shed the offending Leptospira spp. in the urine for several weeks. Antibiotic treatments are sometimes used in hopes of decreasing Leptospira shedding in infected horses or prophylactically in exposed pregnant mares but documentation of efficacy is lacking. Horses with Leptospira - associated acute renal failure can be successfully treated with antibiotics and supportive care. Recurrent uveitis is commonly associated with leptospirosis in North American horses and although horses may have chronic intraocular infection triggering an immune disease, systemic antimicrobial therapy has not been effective in eliminating the organism from the eye. An equine approved Leptospira Pomona type kennewicki vaccine is now available in North America.     

Prevalence of equine ulcerative keratomycosis in Colorado and association of environmental factors: A retrospective and descriptive study (2002–2017)

Equine ulcerative keratomycosis is relatively commonly presented to teaching hospitals in North America, with a prevalence from 24 to 86%. Horses in Colorado may have lower risk due to the dry mountain climate, but data are lacking. This study aimed to determine the prevalence of ulcerative keratomycosis amongst horses with ulcerative keratitis presented to Colorado State University Veterinary Teaching Hospital (CSU-VTH) ophthalmology service and to evaluate environmental factors (season, temperature, humidity, wind speed and elevation) associated with ulcerative keratomycosis in Colorado. A database search identified horses with ulcerative keratitis presented to the ophthalmology service at CSU-VTH from January 2002 to August 2017. Sixty-one horses met the inclusion criteria of a corneal cytology and/or culture or histopathology at the time of diagnosis; cases lacking that were excluded. Environmental factors at the boarding sites, including season, temperature, humidity, wind speed and elevation and clinical outcomes for fungal cases, were recorded. Prevalence of fungal infection amongst equine ulcerative keratitis was 16.4% (10/61), suggesting that CSU-VTH has considerably fewer ulcerative keratomycosis cases than other veterinary teaching hospitals in North America. Spring (50%, 5/10) and fall (40%, 4/10) had the highest prevalence of fungal ulcerative keratitis in Colorado. Only one case was reported in summer (10%, 1/10); no horses were positive (0%, 0/10) in winter. Only wind speed seemed to influence the development of ulcerative keratomycosis with higher wind speeds associated with greater rates of fungal involvement (P = 0.047). Other environmental factors did not show a detectable association (all P-values >0.05). Outcomes were variable. It was concluded that horses from the area of CSU-VTH appear to be at lower risk for ulcerative keratomycosis than from the areas around other North American veterinary teaching hospitals that have reported data. Most horses with keratomycosis in this area present in the spring and fall.     

Carriage of methicillin-resistant Staphylococcus aureus by veterinarians in Australia

Objective To estimate the prevalence of carriage of methicillin‐resistant Staphylococcus aureus (MRSA) among Australian veterinarians. Methods Individuals attending veterinary conferences in Australia in 2009 were recruited to provide nasal swabs and complete a questionnaire about their professional activities. Swabs were processed by standard methods for detecting MRSA and questionnaire responses were used to group veterinarians according to their areas of major work emphasis (species and practice type). Prevalence was estimated for each of these grouping and contingency tables and regression tree analysis used to explain the variation in MRSA carriage. Results Among the 771 respondents ‘industry and government veterinarians’ (controls) had the lowest prevalence of MRSA carriage at 0.9%. Veterinarians with horses as a major area of work emphasis had a prevalence of 11.8% (13‐fold that of controls) and those whose only major emphasis was horses had a prevalence of 21.4% (23‐fold that of controls). Veterinarians with dogs and cats as a major activity had a 4.9% prevalence (5‐fold that of controls). Prevalence rates for other major activities (pigs, dairy and beef cattle, avian and wildlife) were also increased, but were estimated from smaller numbers of respondents. Regression tree analysis clearly isolated equine veterinarians and dog and cat practitioners as groups at increased risk of carriage of MRSA. Conclusion Carriage of MRSA is a notable occupational health issue for veterinarians in clinical practice in Australia, particularly those who work with horses.     

Attempted eradication of methicillin-resistant staphylococcus aureus colonisation in horses on two farms

REASONS FOR PERFORMING STUDY: Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging equine and zoonotic pathogen. Infection control protocols can be used to control MRSA in human hospitals, but measures to eradicate MRSA on horse farms have not been evaluated. OBJECTIVES: To describe an MRSA eradication programme that was used to attempt to eliminate MRSA colonisation among horses and horse personnel on 2 equine farms. METHODS: Active surveillance cultures and infection control protocols were implemented on 2 farms with endemic MRSA. RESULTS: Active screening and strict implementation of infection control protocols resulted in a rapid decrease in number of colonised horses on both farms. The majority of horses eliminated MRSA without antimicrobial treatment. On one farm colonisation was eradicated, while only 2 (3%) colonised horses remained on the other farm at the end of the study. CONCLUSIONS: Although at this stage the benefit of eradication of MRSA from populations of horses and cost-benefit studies have not been established, this study illustrates that short-term eradication can be achieved with a policy of segregation, enhanced infection control precautions and repeated testing of groups of animals. POTENTIAL RELEVANCE: Infection control practices should form the basis of MRSA control. Antimicrobial therapy does not appear to be required for eradication of MRSA colonisation in horses and control of MRSA on farms. In appropriate circumstances, these methods may be useful for controlling the spread of this potentially serious pathogen.     

Evaluation of a real-time polymerase chain reaction assay for rapid identification of methicillin-resistant Staphylococcus aureus directly from nasal swabs in horses

Screening for nasal colonization is an important aspect of many methicillin-resistant Staphylococcus aureus (MRSA) control programs. Real-time polymerase chain reaction (RT-PCR) is an attractive alternative to standard culture techniques because of the considerably shorter turnaround time. An assay has been validated for diagnostic purposes in humans, however this methodology has not been evaluated in horses. The purpose of this study was to compare an RT-PCR assay for rapid identification of MRSA directly from nasal swabs in horses to standard culture techniques. Nasal swabs collected from 293 horses were processed using a commercial RT-PCR assay (IDI-MRSA, GeneOhm Sciences, San Diego, CA) according to the manufacturer's instructions. The swabs were also cultured and MRSA was identified according to standard protocols. Initially only 176/293 samples yielded valid PCR results. Two of 176 and 167/176 samples were positive and negative, respectively, by both PCR and culture. Seven of 176 samples were positive by PCR and negative by culture, whereas 0/176 samples were negative by PCR and positive by culture. The kappa statistic was 0.35, which represented poor agreement between the tests. Of the remaining 117 samples, 105 samples were initially reported as "unresolved". Following one freeze-thaw cycle of the lysates, the recommended technique to resolve such samples, 61/110 (55%) samples remained unresolved. In this study, the IDI-MRSA assay was not a clinically practical screening test for horses harbouring nasal MRSA. Its agreement with culture was poor and the high unresolved rate (37%) also significantly decreased the clinical utility of the test.     

Management factors affecting stereotypies and body condition score in nonracing horses in Prince Edward Island

In North America, there are few representative data about the effects of management practices on equine welfare. In a randomized survey of 312 nonracing horses in Prince Edward Island (response rate 68.4%), owners completed a pretested questionnaire and a veterinarian examined each horse. Regression analyses identified factors affecting 2 welfare markers: body condition score (BCS) and stereotypic behavior. Horses' BCSs were high (mean 5.7, on a 9-point scale) and were associated with sex (males had lower BCSs than females; P < 0.001) and examination date (P = 0.052). Prevalences of crib biting, wind sucking, and weaving were 3.8%, 3.8%, and 4.8%, respectively. Age (OR = 1.07, P = 0.08) and hours worked weekly (OR = 1.12, P = 0.03) were risk factors for weaving. Straw bedding (OR = 0.3, P = 0.03), daily hours at pasture (OR = 0.94, P = 0.02), and horse type (drafts and miniatures had a lower risk than light horses; P = 0.12) reduced the risk of horses showing oral stereotypies. Some of these results contradict those of other studies perhaps because of populations concerned.