Veterinary Services

Nutritional and metabolic conditions

A ten-week-old boar was found dead in a group of 20 on a unit with 400 finishers. An on-farm postmortem examination revealed hydrothorax, hydropericardium and pulmonary oedema. Necrotic lesions were detected in the heart in the apex of the ventricles. Histopathology provided evidence of a widespread degenerative cardiomyopathy. In parts there were substantial areas of muscle fibre loss, particularly in sub-epicardial locations. Within the body of the myocardium there were multifocal areas of fibre loss and active degeneration. The changes were consistent with a nutritional type cardiomyopathy/hepatosis dietetica.

Hepatosis dietetica was also diagnosed in grower pigs on an outdoor rearing unit in Perthshire. Interestingly, a sow that died during farrowing on the same farm was found to have similar cardiac and hepatic pathology suggesting that Vitamin E deficiency was affecting older animals on the unit as well as growers. The unit had reported ongoing problems with stillborn piglets and sow deaths around farrowing. The sow was in very good bodily condition and the carcase was fresh. Necropsy provided evidence of laryngeal and pulmonary oedema. The lung parenchyma was heavily petechiated in some areas and a marked pericardial effusion was noted. There was dark ascitic fluid within the abdomen and the liver appeared swollen and mottled. Small areas of ulceration were noted in the fundic area of the stomach. Three piglets were still within the uterus; the remainder had been stillborn.

Alimentary tract disorders

A high health status, rearing herd in Rosshire reported poor growth performance and diarrhoea in weaned pigs. Gross postmortem and histopathological findings were consistent with postweaning multisystemic wasting syndrome (PMWS) with concurrent spirochaetal-type colitis. Brachyspira pilosicoli infection was also confirmed by PCR testing.

B. pilosicoli infection was also confirmed in intestines submitted from two nine-week-old pigs from a unit which was experiencing diarrhoea at 10 percent morbidity but with no reported mortalities. There were 1300 pigs in eight batches and all were affected. On histopathology the colonic sections showed widespread moderate mucosal inflammatory changes comprised of mainly mononuclear cell infiltrates. There was early goblet cell hyperplasia and many large, fine spirochaete bacteria in crypts. The identity of the bacteria was confirmed to be Brachyspira pilosicoli by PCR testing.

Abortion

Three piglets were submitted from a herd that experienced four abortions recently. Two of the piglets had been stillborn and one had partially inflated lungs. There was evidence of foetal stress as all three had ingested meconium. A growth of a Bacillus species was isolated in culture from the foetal stomach contents. There was no evidence of Leptospira bratislava or of porcine parvovirus on serology. Unfortunately placental samples were not available for histopathological examination as these would help to interpret the significance of the Bacillus species isolate.