Veterinary Services

Generalised and systemic disorders

Internal lesions consistent with acute traumatic damage were confirmed on postmortem examination of a four-week-old, unweaned pig. There was evidence of severe intra-abdominal haemorrhage following rupture of the liver. Investigations are ongoing as the cause of the trauma could not be established and the unit reported five sudden deaths in the preceding week in pigs due to be weaned.

A four and a half-week-old gilt was submitted from a batch of 260 that had been weaned seven days previously. A couple of piglets had been found dead on day five after weaning and this one was found dead on day seven. The rest of the group appeared healthy and there was no evidence of coughing or scouring in the group. The small intestines were hyperaemic and contained orangey-brown liquid contents. The mesenteric lymph nodes were enlarged and hyperaemic. The caecal and colonic musosae had fibrinous-type yellow, crumbly material adherent throughout. Profuse growths of group B salmonella species (4,15, 12:I:- strain) were isolated from the lung, liver and caecal contents. The deaths were attributed to salmonellosis.

Alimentary tract disorders

Histopathological examination of tissues from three-day-old scouring piglets indicated a viral-type enteropathy. Acute rotavirus infection was suspected but the virus was not demonstrated in intestinal contents. The outdoor unit reported a significant scour problem in cross-fostered piglets from sows producing large litters. The cause of the viral-type enteropathy remains uncertain.

PCR testing of faecal samples from a large colitis outbreak detected both Lawsonia intracellularis and Brachyspira hyodysenteriae indicating that both porcine proliferative enteropathy (PPE) and swine dysentery were involved.

Fixed tissues were received for histology from three, two-month-old, cross-bred pigs from another unit experiencing poor growth rates. Examination of the samples of ileum and colon revealed severe, widespread lesions of PPE in all three. In the samples from one pig there was necrotising, ulcerative ileitis with marked fibroplasia and inflammation in the denuded submucosal tissue indicating the chronicity of the lesion. Examination of the lung tissues showed enzootic-type pneumonia and widespread suppurative inflammation consistent with complicating bacterial secondary infection. Ill-thrift was attributed to a combination of PPE and pneumonia.

Examination of two faecal samples from scouring adult sows revealed significant counts of Oesophagostomum dentatum eggs in both.

Diseases of the locomotive system

Two lower limbs were submitted from a farm with a history of severe lameness and ulcerative leg lesions in sows. Both showed severe, chronic ulcerative pododermatitis over the accessory digit area (medially and laterally) with marked swelling of the fetlock area (Figure 3; see Related Documents at top right-hand side). The large granulated ulcers were approximately five centimetres in diameter. One of the three ulcers was encapsulated with no evidence of lesions extending into the deeper tissues. The other two (and largest) ulcers showed underlying necrotic tissue and tracking infection into deep-seated tissues including tendon sheaths and joint capsule. The accessory digits were missing from all three ulcerated sites. The one remaining accessory digit showed traumatic injury to the coronary band area and early inflammatory changes. The main claws on each foot were normal with no evidence of coronary band lesions. The lesions suggested primary traumatic injury to the accessory digits complicated by bacterial infection and ongoing trauma. Bacterial cultures from the deep-seated lesions yielded mixed bacterial growths including Arcanobacterium pyogenes, Staphylococcus aureus and Streptococcus suis.

Diseases of the Nervous System

Histopathological examination of fixed brains from two 12 week old, Large White pigs revealed perivascular haemorrhages and acute perivascular inflammatory changes including eosinophil infiltrates consistent with salt poisoning/water deprivation. Approximately 20 of 80 pigs were affected after the water supply has been disrupted for 48 hours.