• Journal of Veterinary Clinics
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• v.9 no.2
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• pp.401-406
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• 1992

For the purpose of effective treatment and prevention of porcine respiratory diseases, Enrofloxacin(Baytril premix) was administered in the feed to trial herd occurred sporadically the respiratory diseases and then a serious investigation was carried out on the therapeutic effect, weight gain, feed conversion rate and lung lesion scoring. The results obtained were as follows, 1. The grower pigs which were administered with Baytril premix for 10 days gained the average body weight of 31kg for 33 days compared to 20.5kg of control group(p<0.05). Also drastical improvement of feed conversion rate(p<0.05) and disappearance of clinical signs were approved. 2. Average scorings of lung lesions were 7.92% in the medication group and 15.8% in the control group respectively. 3. Respiratory diseases outbreaked in the trial farm were pleuropneumonia caused by Actinobacillus (Haemophilus)pleuropneumoniae, Mycoplasmal pneumonia and Pasteurellosis.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.318-326
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• 1999

Respiratory pathogenic effects of several porcine reproductive and respiratory syndrome virus(PRRSV) isolates were examined in swine tracheal ring(STR) cultures by examining their effect on ciliary activity. One high and one low pathogenic PRRSV isolates were then selected and their pathogenicity investigated in 3-week-old conventional PRRSV-seronegative pigs. Ten pigs each were inoculated intranasally with the high or low pathogenic PRRSV isolate and 6 pigs were sham inoculated as negative controls. Two pigs each from the inoculated group and one pig each from negative control group were killed on 4, 7, 14, 21 and 28 days postinoculation(pI). At necropsy, degrees of gross lung lesion was determined. Turbinate, tonsil, trachea and lung samples were collected for virus isolation or histopathology. Gross lung lesions were observed mainly on 14 days PI with high and low pathogenic isolates inducing moderate diffuse and mild gross lung lesions, respectively. Inoculation of either the high or low pathogenic virus resulted in loss of cilia in ciliated epithelium of turbinates and trachea between 7 and 28 days PI. High pathogenic virus caused increased number of Goblet cells in the tracheal epithelial layer between 4 and 21 days PI whereas the low pathogenic virus did it between 14 and 28 days PI and with a lesser degree. Although both viruses produced interstitial pneumonia, the lesion was less severe with the low pathogenic virus. The isolation of high pathogenic virus from tissues and sera was earlier and more consistent than that of the low pathogenic virus. The agreement between in vitro and in vivo tests indicates that STR cultures may be used as a routine method to determine the respiratory pathogenicity of PRRSV isolates.

• Korean Journal of Veterinary Service
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• v.39 no.4
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• pp.231-237
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• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.313-320
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• 2011

The purpose of this study was to investigate association with gross lesions and causative pathogens of porcine respiratory disease complex (PRDC) including porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), Mycoplasma hyopneumoniae (MH), Pasteurella multocida (PM), Actinobacillus pleuropneumoniae (APP), Haemophilus parasuis (HP) in slaughtered pigs. A total of 1,200 lung samples were collected randomly from slaughtered pigs in Korea during August of 2010 through July of 2011. The gross lesions were classified according to the six stages (0, 1~10, 11~20, 21~30, 31~40 and ${\geq}41$, unit=%) and 48 samples from each stage were selected to detect viral and bacterial pathogens. The results according to the six stages were 100 (8.3%), 259 (21.6%), 326 (27.2%), 213 (17.8%), 144 (12.0%) and 158 (13.2%) cases, respectively. Prevalence of pneumonia according to season was 87.0~96.7% and the highest prevalence was in spring. In detection of pathogens by PCR, 53 samples were not detected any causative pathogens of PRDC. PCV2, PRRSV, SIV, MH, PM, APP serotype 2, APP serotype 5 and HP were positive in 45.5%, 12.5%, 10.4%, 60.1%, 1.7%, 13.9%, 12.2% and 15.6%, respectively. In co-infection, PCV2-MH was the most detected causative pathogens of PRDC. The detection rate of PCV2 and PRRSV was the highest in spring, of SIV, MH and HP was in winter. The detection rate of APP-2 and APP-5 had no seasonal prevalence. The more severe gross lesions increased, the higher the detection rate showed.