Veterinary Services

Greasy pig disease due to infection with Staphylococcus hyicus was diagnosed in three six-day-old piglets. The irregular, pale brown, slightly greasy, skin lesions were extensive over the head, body and limbs. The piglets were unresponsive to treatment with amoxicillin despite the S.hyicus isolate being sensitive in vitro to ampicillin and penicillin.

Respiratory tract conditions

Two sets of lungs were examined as part of an investigation into severe respiratory signs and deaths affecting 10 to 16-week-old pigs. The pigs received feed medicated with chlortetracycline but clinical signs continued. Both sets of lungs submitted showed areas of consolidation and there was evidence of pleurisy in one case. Pasteurella multocida was isolated from one case and Actinobacillus pleuropneumoniae from the other. Both of these pathogens could have been responsible for the problems experienced on the unit. 

Pneumonia and gastric ulceration were diagnosed in a 14-week-old gilt. The gross and histopathological findings were suggestive of enzootic pneumonia and Pasteurella multocida was isolated from lung tissue. The carcase was also pale and the blood was very watery suggestive of an anaemia. No source of the blood loss could be identified however there was a large gastric ulcer present which could have been responsible for chronic low-grade haemorrhage.

Nutritional and metabolic conditions

Rickets type osteodystrophy and osteoporosis were identified in finishing pigs from a commercial breeder-finisher pig unit with 250 sows. Lameness and unsteadiness in association with short and/or thickened legs had been noted in several pigs and the abattoir reported broken ribs in a high proportion of animals being slaughtered. Some pigs in each batch of finishers were too lame for road haulage and had to be culled on-farm. In addition some apparently fit bacon pigs had become unsteady, collapsed and started fitting when being moved from the finishing pens to the loading bay. These too were unfit to travel and had to be culled. Necropsy of a typically affected pig found that both fore and hind limbs appeared shorter than normal with evidence of weight-bearing on the knees.  The costo-chondral junctions were markedly enlarged (Figure 6 - see top righ-hand side) and there were multiple rib fractures and poor mineralisation of the ribs, such that they could be easily sliced with a knife.  Long bones showed thickening over the growth plates and both radii had poorly-healed fractures.  Bone ash values of rib and femur were 8.5% and 8.9% respectively (reference range 40 to 50%). The ratios of calcium to phosphorus were normal.  Histopathology showed changes consistent with rickets and osteoporosis. SACCVS postulated that problems were due to dietary mineral and/or vitamin deficiencies and an investigation was launched.  This revealed that problems started when the farm changed from commercial compound rations to home-mixed rations to which proprietary vitamin and mineral balancers were added in accordance with the diet specifications that were professionally formulated for the unit. Since changing to home-mix rations, the farmer had noted a high prevalence of urine-drinking in the weaners and growers, as well as the conformation changes in the finishers. Inspection of the water supplies showed no faults with provision at any of the production stages. Amendments to the vitamin and mineral supplementation was carried out and investigations continue.

Alimentary tract disorders

Lawsonia intracellularis was detected by PCR in pooled faeces from a pig unit experiencing a problem with diarrhoea in growing pigs in a straw-bedded continuous flow unit. SACCVS advised a vaccination programme for weaners as well as management changes to allow an all-in, all-out system.