• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.132-134
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• 2017

Streptococcus equi subsp. equi which is a Gram-positive bacteria causes strangles a highly contagious disease that affects the respiratory system of the horse. The disease is characterized by fever, nasal discharges and enlargement of the lymph nodes in the head and upper neck region. This study was performed to monitor the level of serum strangles antibody titers of horses in Jeju. A total of clinically healthy 122 horses (41 horses less than 5 months, 81 horses more than 1 years old) were included in this study. Serum antibody titers against strangles were measured by means of Passive haemagglutination (PHA) titers. As the results, the level of foals was definitely low. The results of this study have shown that there is a need to consider the vaccination against strangles infection at foals.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.263-268
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• 2023

Despite regular vaccinations, equine influenza virus (EIV) and Streptococcus equi subsp. equi (strangles) are the cause of highly contagious respiratory infections in horses. Many recent studies have reported that the concurrent administration of two vaccines could simplify horse management and minimize veterinary expenses. However, there is little information available regarding the efficacy of concurrent vaccinations against EIV and strangles. In this study, we evaluated EIV-specific antibody responses following the single EIV vaccination with the recombinant viral-vectored EIV vaccine or concurrent vaccination with the EIV and inactivated strangles vaccines. Blood samples were collected at 1-, 2-, 4-, and 8 weeks post-immunization (wpi) from each group. EIV-specific antibodies were evaluated by enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition (HAI) assay. Both single and concurrent vaccination showed similar levels of EIV-specific serum immunoglobulin g (IgG) at 1 and 2 wpi. However, at 4 to 8 wpi, the EIV-only vaccination group showed significantly higher serum IgG levels than those from the concurrently vaccinated group. The HAI titers showed similar trends as the ELISA data, except at 8 wpi when both groups presented HAI titers with no significant differences. These data demonstrate that the concurrent vaccination against EIV and strangles could compromise the humoral immune response to equine influenza between vaccination intervals, which suggests the use of the consecutive vaccination protocol for EIV and strangles rather than concurrent vaccination.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.158-163
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• 2006

This work describes an outbreak of strangles due to Streptococcus equi subsp. equi in 1 to 2 years old Thoroughbred horses. A total of 7 samples were collected from 5 horses in two different horse farms during 2003. Six ${\beta}$-hemolytic colonies selected from each sample were identified by biochemical tests using API STREPTO followed by PCR amplification which is able to recognize unique region of SeM gene of S. equi subsp. equi. All colonies selected from the ruptured lymphadenitis of 2 horses in farm A were identified as S. dysgalactiae subsp. equisimillis. It seems to be secondary infection because the sampling sites have been already opened and the horses have been treated with antibiotics for a week. All colonies from 2 submandibular lymphadenitis samples in Farm B were S. equi subsp. equi while the isolates from 3 nasal discharges in this farm were mixed with S. equi subsp. zooepidemicus.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.41-44
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• 2015

We reported an outbreak of clinical strangles in thoroughbred horses due to capnophilic Streptococcus equi subsp equi in South Korea. On three different farms, we isolated 17 S equi subsp equi isolates from 29 horses with or without abscesses in their lymph nodes. Of the 17 isolates, two isolates from clinical cases grew well in aerobic conditions, whereas 7/7 isolates from clinical cases and 8/22 isolates from the nasal discharges of horses did not. The latter 15 isolates were capnophilic, oxygen-sensitive, and $CO_2$-requiring S equi subsp equi, which could not grow in aerobic conditions, but which grew well in a $CO_2$ incubator with 5% $CO_2$, in anaerobic conditions using a GasPak, and with reduced oxygen tension in a candle jar. This study is the first report of a strangles outbreak caused by capnophilic S equi subsp equi in South Korea.

• Korean Journal of Veterinary Service
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• v.43 no.2
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• pp.59-65
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• 2020

The aim of the study was to investigate the seroprevalence of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4), equine influenza virus (EIV), and Streptococcus (S.) equi subspecies equi in the horse population of Jeju. Serum samples were taken from 71 horses, regularly vaccinated with EHV-1 and strangles twice (April and November) a year. In April 2014, seropositive rates of EHV-1 and strangles were 24.5% and 84.5%, while in November, were 26.8% and 62.0%, respectively. A total of 1,144 serum samples, including Jeju native horses, Halla horses, and Thoroughbred horses were collected from slaughter house for 4 years (2014 to 2017) and it is unclear the animals were vaccinated or not. The seropositive rates in Jeju was 21.9% (250/l,144) for EHV-1, 96.4% (1,103/1,144) for EHV-4, 14.6% (129/882) for EIV, and 79.3% (879/1,108) for strangles. The seropositive rate was the highest in Thoroughbred, but lowest in Hala horse.