The prevalence and trends of economically important porcine production diseases in Northern Ireland Natalie Brush 3rd Year PhD Student Supervisors: Dr. John McKillen (AFBI) and Dr. Ultan Power (QUB) Note: Do not change background, font or font colours.

Project aims This work is part of a larger study that is focusing on the extent of pleurisy in Northern Ireland pigs by examining the associated microbiological, management and environmental risk factors How much is there in NI? Determine the prevalence of pleurisy (and other conditions) in Northern Ireland pig herds What causes it? Identify the microorganisms involved and assess the farm management, and environmental risk factors for pleurisy 3. How much does it cost the industry? Determine the economic impact of pleurisy in pigs This work is part of a larger study. What I will be talking about today is the prevalence of pleurisy and other production diseases in NI. This is the focus of this presentation.

Background = Economic losses Meat inspection is the visual inspection of carcass and offals for the purpose of: (a) Ensuring that all meat entering the food chain is fit for human consumption (b) To ensure all meat is free from disease and does not pose a threat to human health Inspection of meat post-slaughter provides an opportunity for pig herd health to be assessed Porcine production diseases result in; Reduced growth Reduced feed efficiency Reduced carcass quality = Economic losses

Lesion Monitoring Data set 1 (Individual pig pathologies) 90,938 pigs 1145 batches 2013-2014 Data set 2 (Average prevalences) 10 seasons from 2008 to 2012 6 seasons from 2013 + 2014 Dealing with two data sets. Data set 1 is indiviual pig data from 2013-2014. Data set 1: As part of the Pig ReGen pig health and welfare checks, lesion monitoring occurs in abattoirs 3 times a year (spring, summer and autumn) where 8 different lesions are scored. Data set 2 is average prevalence data only for these 8 lesions over 7 years.

Macroscopic lesions Respiratory Enzootic pneumonia-like (EP) Pleurisy (PL) Pleuropneumonia (PP) Lung abscesses EP – areas of lung consolidation PL – fibrous adhesions between lung and between lung and chest wall PP – focal areas of lung consolidation Lung abscesses – Localised areas in the lung Pictures taken from BPHS/BPEX lesion scoring information leaflet

Macroscopic lesions Non-Respiratory Pericarditis Milk spot liver Papular dermatitis (PD) Tail bite Peri – inflammation of the pericardium Milk spots – white spots of healing tissue on the liver PD – red papules on the skin Tail bite – damage to the tail Pictures taken from BPHS/BPEX lesion scoring information leaflet

Scoring System Lesion Pathology Scoring system Enzootic pneumonia Red/tan/grey lung consolidation affecting the cranioventral regions Goodwin-Muirhead 55 point scoring system (Goodwin et al., 1969) Pleurisy Fibrinous or fibrous adhesions on the lung and/or between the lung and chest wall 0 (no lesions) to 5. Score increasing with severity. Pleuropneumonia Focal areas of lung consolidation usually affecting the caudal lobes Presence/Absence Lung abscess Localised abscess within the lung Pericarditis Fibrinous or fibrous adhesions on the pericardium Milk spots White areas of healing foci on hepatic tissue Papular dermatitis Red papules found widespread across the skin 0 (no lesions) to 3. Tail bite Damage to the tail (recent or old) Scoring system is binary for all conditions except EP (goodwin-murihead 55 point scoring system), PL (0-5 scoring system) + PD (0-3 scoring system). Scores increasing with severity.

The prevalence of porcine production diseases in Northern Ireland pig herds Established the prevalence of all the different conditions monitored at slaughter. 1. Animal level prevalence – milk spot lesions are the most prevalent condition with 16% of animals presenting with lesions at slaughter. Followed by pleurisy at under 10% and then pneumonia lesions. All other conditions affect <5% of animals. 2. Herd level prevalence – pleurisy is the most prevalent condition affecting just under 75% of herds (three-quarters of all herds in NI). This is followed closely by pericarditis. Milk spot lesions are the third most prevalent disease and pneumonia the fourth.

How does the NI data from 2013/14 compare to the rest of the UK? EP is lower in NI (6.69%) than England and Wales and Scotland between 2005-2012, 22.7% and 29% respectively Pleurisy lesions in NI (11% of pigs in 2012, 9.21% across 2013-2014) are similar to those observed in England and Wales (11.53% in 2012) and lower than in Scotland (15.47% in 2012) Pleuropneumonia and lung abscess were reported at very low levels and are similar to those prevalences reported for the rest of the UK A recent publication by Eze et al., 2015 compared the respiratory lesions across 3 monitoring systems (E&W, NI & Scotland). What we have reported is lower levels of EP that E&W and Scotland. Similar PL levels to E&W but lower than Scotland. Similary low levels of PP + lung abscesses

The prevalence of porcine production diseases in Northern Ireland pig herds Probability of significance for correlations between lesions types recorded in pigs at slaughter in Northern Ireland (2013-2014). Lesion Enzootic pneumonia Pleurisy Pleuro-pneumonia Pericarditis Lung abscess Milk spot Papular dermatitis Tail bite Enzootic pneumonia - <0.001 0.0083 0.0034 0.0021 0.0307 0.0052 Papular dermatitis Correlations observed between lesions at slaughter. Correlations seen between respiratory lesions, parasitic lesions and between pleurisy and tail bite lesions.

The prevalence of porcine production diseases in Northern Ireland pig herds These two graphs show the changes in prevalence over time. The pathologies are separated just based on scale on the vertical axis, for convenience. Top graph displays the most prevalent conditions – a decrease in EP + an increase in pericarditis. Bottom graph displays the least prevalent conditions – decrease in lung abscesses.

†Pleuropneumonia lesions were not recorded prior to autumn 2009 Trend in lesion prevalence observed over 16 seasons from pigs slaughtered in Northern Ireland (2008-2014) Lesion Probability Trend Enzootic pneumonia <0.001* Negative Pleurisy 0.253 None Pleuropneumonia† 0.995 Lung abscess 0.007* Pericarditis 0.003* Positive Milk spots -0.7331 Papular dermatitis 0.083 Tail bite 0.334 Mann-Kendall time trend analysis performed on AVERAGE prevalences only (data set 2) and also included additional average prevalences from 2013+2014 seasons Trend analysis was taken over 16 seasons from autumn 2008 to autumn 2014. Statistically significant results for a decrease in EP over time in NI. Also found a decrease in lung abscesses and an increase in pericarditis over time, but on a much smaller scale. No trend with any of the other conditions, including pleurisy. †Pleuropneumonia lesions were not recorded prior to autumn 2009

Summary Determined the prevalence of 8 economically important production diseases at both animal and herd level Established that relationships exist between different lesion types Decrease in enzootic pneumonia-like lesions and lung abscesses over the past 7 years (2008-2014) and an increase in pericarditis lesions

Future work Take home message Commencing a longitudinal/environmental study to further investigate the pathogens involved with pleurisy and their infection dynamics on farms Farm management survey Calculate the economic cost of pleurisy Take home message We hope to be able to inform the industry as to the extent and causes of porcine production diseases in NI The economic element to the study will allow producers to do a cost/benefit analysis on the introduction of preventative measures

Acknowledgements Dr. John McKillen (AFBI) and Dr. Ultan Power (QUB) Porcine Virology Team at VSD Department of Agriculture and Rural Development (DARD) Jesus Borobia and Dermot Sparrow at Moss Vet Clinic AFBI Biometrics Howard Tonks and Pig ReGen Ltd.