Veterinary Services

Nutritional and metabolic disorders
Seven pigs were submitted for post mortem examination from a 3000-place finishing unit. A total of 70 to 80 deaths among sixteen-week-old pigs in good body condition had been reported over the preceding three weeks. An apparently rapid onset ataxia, without other specific central nervous signs, was noted in some of the pigs shortly before death. Histopathological examination of tissues revealed acute degenerative cardiomyopathy and hepatosis dietetica consistent with inadequate vitamin E intake. The pigs were on a liquid feeding system and there had been concerns over the provision of adequate quantities of drinking water in some areas of the unit. A marked reduction in the mortality rate in some pens appeared to coincide with improvements made to the water supply, prior to the confirmation of vitamin E deficiency and extra supplementation in the diet. No neurohistopathological lesions were detected to suggest water deprivation as the primary cause of the deaths, but the possibility of additional stress factors precipitating the problem are being considered as investigations into dietary vitamin E levels continue.

Generalised and systemic conditions
Outbreaks of porcine dermatitis and nephropathy syndrome (PDNS) were reported on two units this month. One case involved a 700-place finishing unit on which six pigs had died over a two-week period. Although post-weaning multisystemic wasting syndrome (PMWS) had been confirmed on the unit supplying the weaners, PDNS had not previously been reported as a problem. The second case involved a newly established herd where four "sudden" deaths were recorded in a group of 200 twelve to fourteen-week-old pigs. Gross skin lesions were absent from all three cases examined, but severe glomerulonephropathy was noted on histopathological examination of kidneys. Cases of PMWS have so far not been recognised on this unit.

Alimentary tract disorders
Porcine proliferative enteropathy (PPE) was diagnosed in three finishing pigs submitted for post mortem examination from a small finishing unit. The pathology in these cases was severe and three manifestations of the infection were observed: necrotic enteritis, regional ileitis and proliferative haemorrhagic enteropathy. Lawsonia intracellularis-specific DNA was detected in intestinal contents by polymerase chain reaction (PCR).

Necrotising enteritis of bacterial aetiology (suspected E. coli) and secondary colonic obstruction were diagnosed in an eleven-day-old piglet found dead with yellow fluid pooled around the head. The other 11 piglets in the litter were apparently healthy. Gross examination revealed a distended abdomen, omphalitis and vomitus at the nares. The mucosa of the ileum had sloughed and the content was white and liquid. The spiral colon was obstructed by dry pasty white material at two points with pooling of the contents proximally. Both E. coli and Clostridium perfringens were isolated in profuse culture from the ileum, but clostridial toxin enzyme immunoassays (EIA) for both alpha and epsilon toxins proved negative and only gram-negative organisms were seen in association with the intestinal lesions on histopathological examination.