A cross-sectional study of colic and rate of return to racing in Thoroughbreds at Seoul Racecourse in Korea between 2010 and 2020

BACKGROUND

The incidence of colic and the outcomes of colic surgery have not been surveyed in racetracks in Korea.

OBJECTIVES

This study examined the incidence, mortality, and case fatality of colic and investigated the effects of age and sex after an exploratory celiotomy on the long-term survival rate (return to racing), subsequent racing performance, and career longevity.

METHODS

The incidence, mortality, and case fatalities of colic were examined over an 11-year period. The records of 40 horses that had undergone a celiotomy, after participating in at least one race and 75 race-matched control horses were analyzed. The racing performance and career length of the horses that returned to racing post-surgery were compared with a control group.

RESULTS

The annual incidence, fatality rate of colic, and annual mortality rate at Seoul Racecourse were 6.5, 2.8 per 100 horse-years, and 0.2 deaths cases per 100 horse-years, respectively. Of the 40 horses that underwent colic surgery, 26 (65%) returned to racing. The likelihood of returning to racing decreased with increasing age of the horses, and geldings had a lower probability of returning. While the performance in the five preoperative races between the two groups was not significantly different, a significant decrease in racing performance was observed after the surgery date (p < 0.01). Horses that underwent colic surgery did not show a significant decrease in career length.

CONCLUSIONS

Surgical treatment for colic at the age of three and four years had a negative impact on the racing performance. On the other hand, there was no significant difference in career longevity between the two groups.

Assessment of the accuracy and precision of the i-Smart 30 VET Electrolyte Analyzer in dogs, cats, cattle and pigs

BACKGROUND

Performance evaluation of point-of-care (POC) electrolyte analyzers is essential for determining their precision and accuracy in clinical practice.

OBJECTIVE

The purpose of this study was to validate the i-Smart 30 VET Electrolyte Analyzer for canine, feline, bovine, and porcine samples in comparison with the ion-selective electrolyte analyzer Roche 9180 electrolyte analyzer.

METHODS

A total of 400 heparinized whole blood samples were collected and analyzed by both instruments for sodium, potassium, and chloride concentrations. Within-run, between-day, and total imprecision were evaluated. Statistical analyses included tests for correlation, regression, bias, and total error.

RESULTS

The coefficients of variation (CV) of both within-run and between-day imprecisions in the i-Smart 30 VET ranged from 0.4-1.6%. In addition, total CV (0.3-1.7%) and total error (0.7-3.7%) of the i-Smart 30 VET were acceptable according to the ASVCP guidelines (< 5%). The correlation between the i-Smart 30 VET and the Roche 9180 was excellent (r > .98). There was no proportional error according to the regression (slope ranges 0.92-1.00, 95% CI includes 1.00), but a constant error was detected for sodium concentration in dogs (interval = 0.5), cattle (interval = 3.0), and pigs (interval = 4.0), and for chloride concentration in cats (interval = 1.0). Most of the bias was within 95% CI, and the total error range (0.8-3.5%) was acceptable according to ASVCP guidelines.

CONCLUSION

The i-Smart 30 VET Electrolyte Analyzer provides precise and accurate measurements of sodium, potassium, and chloride concentrations in whole blood samples from dogs, cats, cattle, and pigs.

Molecular detection and genotyping of Japanese encephalitis virus in mosquitoes during a 2010 outbreak in the Republic of Korea

Japanese encephalitis virus (JEV), a mosquito-borne zoonotic pathogen, is one of the major causes of viral encephalitis. To reduce the impact of Japanese encephalitis among children in the Republic of Korea (ROK), the government established a mandatory vaccination program in 1967. Through the efforts of this program only 0-7 (mean 2.1) cases of Japanese encephalitis were reported annually in the ROK during the period of 1984-2009. However, in 2010 there was an outbreak of 26 confirmed cases of Japanese encephalitis, including 7 deaths. This represented a >12-fold increase in the number of confirmed cases of Japanese encephalitis in the ROK as compared to the mean number reported over the last 26 years and a 3.7-fold increase over the highest annual number of cases during this same period (7 cases). Surveillance of adult mosquitoes was conducted during the 2010 outbreak of Japanese encephalitis in the ROK. A total of 6,328 culicine mosquitoes belonging to 12 species from 5 genera were collected at 6 survey sites from June through October 2010 and assayed by reverse-transcription polymerase chain reaction (RT-PCR) for the presence of JEV. A total of 34/371 pooled samples tested positive for JEV (29/121 Culex tritaeniorhynchus, 4/64 Cx. pipiens, and 1/26 Cx. bitaeniorhynchus) as confirmed by sequencing of the pre-membrane and envelope protein coding genes. The maximum likelihood estimates of JEV positive individuals per 1,000 culicine vectors for Cx. tritaeniorhynchus, Cx. pipiens, and Cx. bitaeniorhynchus were 11.8, 5.6, and 2.8, respectively. Sequences of the JEV pre-membrane and envelope protein coding genes amplified from the culicine mosquitoes by RT-PCR were compared with those of JEV genotypes I-V. Phylogenetic analyses support the detection of a single genotype (I) among samples collected from the ROK in 2010.

A diagnostic algorithm to serologically differentiate West Nile virus from Japanese encephalitis virus infections and its validation in field surveillance of poultry and horses

The detection of West Nile virus (WNV) in areas endemic for Japanese encephalitis virus (JEV) is complicated by the extensive serological cross-reactivity between the two viruses. A testing algorithm was developed and employed for the detection of anti-WNV antibody in areas endemic for JEV. Using this differentiation algorithm, a serological survey of poultry (2004 through 2009) and horses (2007 through 2009) was performed. Among 2681 poultry sera, 125 samples were interpreted as being positive for antibodies against JEV, and 14 were suspected to be positive for antibodies against undetermined flaviviruses other than WNV and JEV. Of the 2601 horse sera tested, a total of 1914 (73.6%) were positive to the initial screening test. Of these positive sera, 132 sera (5.1%) had been collected from horses that had been imported from the United States, where WNV is endemic. These horses had WNV vaccination records, and no significant pattern of increasing titer was observed in paired sera tests. Of the remaining 1782 positive sera 1468 sera (56.4%) were also found to contain anti-JEV antibodies, and were interpreted to be JEV-specific antibodies by the differentiation algorithm developed in this study. The remaining 314 horses (12.1%) for which a fourfold difference in neutralizing antibody titer could not be demonstrated, were determined to contain an antibody against an unknown (unidentified or undetermined) flavivirus. No evidence of WNV infections were found during the period of this study.