Epidemiological studies on lesions in finishing pigs in the Netherlands. I. Prevalence, seasonality and interrelationship

Data from meat inspection services at two large regional abattoirs in the Netherlands were used to study the prevalence and seasonal variation of pathological lesions in finishing pigs. A data recording system including 12 codes for lesions was used. From 1 February 1987 until 1 February 1989, approximately 550 000 finishing pigs originating from 205 pig herds were slaughtered and observed. The lesions atrophic rhinitis, arthritis, inflammation of the leg, inflammation of the tail, skin lesions, partially affected and condemned liver, and abscess (es) in the lungs occured at frequencies of less than 1%. Only some respiratory disorders occured at frequencies of 2–11%. For all of the lesions investigated there were significant prevalence differences between pig herds, but there were also significant differences in the prevalence between the two slaughterhouses for the lesions arthritis and inflammation of the tail in pigs. The highest prevalences of pneumonia and of the skin lesions were in January–February and the lowest in July–August. The highest prevalences of abscesses in the lungs and of condemned liver were in October–November and the lowest in April–May. The highest prevalence of pleurisy was in June–August and the lowest in December–January. The highest prevalence of arthritis was in August–October and the lowest in February–April. The interralationships between lesions at the herd level were quite limited for most of the lesions.