Alimentary Tract Diseases

Parasitism salmonellosis and Brachyspira pilosicoli

The carcass of a ten-week-old pig was received by Winchester, one of three that had died in a small commercial outdoor herd. The animal was in very thin condition, with a hairy coat and weighed only 8 kg. Post mortem examination demonstrated severe necrotic changes in the ileum and large intestine, with numerous Trichuris worms visible amongst the necrotic debris in the colon and caecum. A worm egg count of 3,200 Trichuris epg was demonstrated in the faeces. The pig also had a 15-cm long Ascarid worm in its stomach. Salmonella Typhimurium and Brachyspira pilosicoli were isolated from the large intestine. The findings indicated a multiple parasitic, Salmonella and spirochaetal involvement in the severe ileitis, colitis and typhlitis present in this animal.

Porcine Intestinal Adenomatosis (PIA)

Sudden onset scouring affected 12 from a group of 30 eight-month-old gilts. Affected gilts looked ill and were markedly paler than unaffected individuals. One of the affected gilts was shot on farm and submitted to Thirsk for investigation. The post mortem revealed the terminal two-thirds of the small intestine to be markedly rigid, pale in colour and smooth with a 'hosepipe' appearance. The wall of jejunum and ileum in the affected areas were markedly thickened with folded mucosa (see figure). Marked necrosis and sloughing of the mucosa were also present in some of the affected areas.

MZN-stained smears of the ileum and jejunum revealed large numbers of intracellular acid fast organisms typical of Lawsonia intracellularis confirming the diagnosis of PIA.

Lesions in the ileum associated with PIA

Respiratory Diseases

Actinobacillus pleuropneumoniae

Ten pigs died suddenly from a group of 480, 14- to 16-week-old housed finishers. Five pigs died on each of two days prior to submission, all were from two pens next door to each other, each pen containing 20 pigs. Four dead pigs were submitted to Bury, all of which had severe fibrinous pleurisy and pericarditis and focal dark red–purple areas of consolidation in the caudal lung lobes, suspicious of acute Actinobacillus pleuropneumoniae infection subsequently confirmed by isolation of the organism. There was no evidence of swine influenza or PRRSV involvement.

Other Diseases

Erysipelas

A further outbreak of erysipelas was diagnosed on an outdoor breeder unit previously investigated by Bury where gilts had missed their pre-farrowing erysipelas booster, or given it late in the days just prior to farrowing. At the time of submission, only one litter was affected out of 155 farrowing in the batch. The problem began the night prior to submission with the entire litter of 11 three-and-a-half-week-old pigs dying suddenly over a period of 12 to 14 hours. The sow was well. Gross lesions were suggestive of a septicaemia with purpling of ear margins, reddening of ventral skin, yellow tingeing of the subcutis and serofibrinous fluid in peritoneal and pleural cavities. Faint pin-point serosal haemorrhages were present over the small intestines and one piglet had pin point haemorrhage over the renal cortices. Pure growths of Erysipelothrix rhusiopathiae were isolated from livers, spleens and meninges, confirming the diagnosis. There was no evidence of active PRRSV infection.

Further Reading

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