A cross-sectional survey on respiratory disease in a cohort of Irish pig farms

Abstract

Background Respiratory disease is one of the most important factors impacting pig production worldwide. There is no available information on the prevalence of key pathogens implicated in Irish pig production. The objective of this study was to describe the prevalence of pleurisy, pneumonia, lung abscesses, pericarditis and liver milk spots in finisher pigs of a cohort of Irish pig farms, and to describe the seroprevalence of: influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSv), Mycoplasma hyopneumoniae (Mhyo) and Actinobacillus pleuropneumoniae (APP). Results In brief, 56 farrow-to-finish farms (29% of the Irish breeding herd) were enrolled in the study in 2017. Data on lungs, heart, and liver lesions were assessed for each farm at slaughter. An average of 417 (range 129–1154) plucks per farm were assessed for pleurisy, pneumonia, lung abscesses, pericarditis, and liver milk spots. Blood samples from 32 finisher pigs were collected at slaughter for each farm. The observed prevalence of pleurisy and pneumonia was one of the lowest reported in similar studies in Europe (13 and 11% estimated average within farm, respectively). Pleurisy lesions were mostly moderate and severe. Pneumonia lesions affected a low level of lung surface (5.8%). Prevalence of pericarditis was mid-high (8%) and the prevalence of liver milk spots was high, with an average of 29% of the livers affected. For serology, 78.6% of the farms were positive for IAV, 50% were positive for PRRSv, 71.4% were positive for Mhyo, and 98.2% were positive for APP. Influenza virus was the main pathogen associated with pleurisy (P < 0.001) and Mhyo was the main pathogen associated with pneumonia (P < 0.001) and pericarditis (P = 0.024). Conclusions Farms affected with pleurisy had moderate to severe lesions. Farms affected with pneumonia had mild lesions, which could be the effect of the generalised use of Mhyo vaccination in piglets. The seroprevalence of IAV, PRRSv, Mhyo and APP in the present study sample is similar to or lower than in other European countries. Further research on the PRRSv and APP strains circulating in Ireland is necessary to support the design of national or regional control plans.

Risk Factors for Antimicrobial Use on Irish Pig Farms

“…This study explored the risk factors for AMU on Irish pig farms using data collected during previously published studies investigating AMU, biosecurity and respiratory disease on Irish pig farms [47,52,53]. The study farms were clients of the Teagasc advisory service and participated on a voluntary basis.…”

“…In the present study, higher AMU on farms vaccinating against IAv may be a consequence of more severe respiratory disease. An association between influenza and pleurisy was reported for the larger cohort of Irish farms [53] and by others [85]. Co-infection is a common feature of the Porcine Respiratory Disease Complex (PRDC), and often, these co-infections are synergistic [86].…”

“…Data on disease status and prevalence of pluck (lungs, heart and liver) lesions were collected from November 2017 to April 2018, as previously described by Rodrigues da Costa et al [53]. Disease status for Influenza A virus (IAv), Porcine reproductive and respiratory syndrome virus (PRRSv), Mycoplasma hyopneumoniae (Mhyo) and Actinobacillus pleuropneumoniae (APP) was determined using serological testing.…”

Application of the MISTEACHING(S) disease susceptibility framework to Actinobacillus pleuropneumoniae to identify research gaps: an exemplar of a veterinary pathogen

“…As such, APP is endemic in many countries, e.g. 98.2% of herds in Ireland were recently reported serologically positive for APP (Rodrigues da Costa et al ., 2020).…”

First Study to Describe the Prevalence of Porcine Reproductive and Respiratory Syndrome Virus and Porcine Circovirus Type 2 among the Farmed Pig Population in the Hong Kong Special Administrative Region

“…Respiratory disease is of particular importance in intensive pig production systems [1,5], especially those with natural ventilation systems [6], such as farms in the Hong Kong Special Administrative Region (HKSAR). Globally, pathogen and disease monitoring are utilized in pig farms and slaughterhouses [1,5,7,8], assisting farmers, industry professionals and governments with their decision making [9,10]. Numerous monitoring methods are available, including use of serological and molecular methods, clinical inspections and slaughterhouse surveillance [6,7,9,11].…”