Veterinary Services

Nutritional and metabolic disorders
One 12-week-old pig was submitted from a unit that had undergone a partial depopulation programme to eliminate enzootic pneumonia (EP) and swine dysentery in July and August. The pig, which had been found dead in straw yard accommodation, was in slightly poor body condition but pulmonary haemorrhage and excess clear pericardial fluid were the only significant lesions observed on gross post mortem examination. Histopathological examination of myocardium revealed evidence suggestive of acute myocardial degeneration (mulberry heart disease) due to inadequate vitamin E intake. The cause of the apparent pulmonary haemorrhage was not determined.

Alimentary tract disorders
Rotaviral infection was diagnosed as the cause of widespread scour in three-day-old piglets on one unit. Rotavirus type B RNA was detected in the faeces of two out of three faecal samples submitted. No other enteropathogens were detected.

Respiratory tract diseases
Increased coughing and "sudden deaths" on one EP-positive unit prompted the submission of two dead finishing pigs. The coughing had apparently disappeared while the pigs were receiving lincomycin and spectinomycin medicated feed but had reappeared when that feed was withdrawn. Post mortem examination revealed scattered lobular areas of pulmonary consolidation in both animals. In one case there was extensive necrosis and diphtheresis of the bronchial epithelium. Histopathological examination of tissues from this animal revealed a severe primary viral-type pneumonia, consistent with swine influenza (although virus isolation was not performed), and an acute necrotising bronchopneumonia. Actinobacillus pleuropneumoniae serotype 3 was isolated from the lung. In the other case there were areas of more homogeneous dark consolidation, with an associated fibrinous pleurisy from which Pasteurella multocida and Streptococcus suis serotype 2 were isolated. The isolation of S. suis serotype 2 from this herd is unusual since the herd does not have a known clinical problem, although it is positive for S. suis serotype 14. We have recently identified a number of "secondary pathogen" serotype 2 isolates that produce quite different pulsed-field gel electrophoresis (PFGE) DNA banding patterns from the usual "primary pathogen" isolates and work is in progress to see if this is a similar case.

Musculoskeletal disorders
Gross and histopathological evidence suggestive of mycoplasmal arthritis was detected in three 3-month-old Landrace boars. The animals had been recently transported and placed in straw yard accommodation, which appeared to have exacerbated the lesions and clinical lameness.