Current Findings in the Regional Veterinary Laboratories December 2005 Cattle Bovine foetal submissions continued to be high during the month. The graph displays the isolation rate for the most common abortefacients encountered (Figure 1). Post-abortion serology results showed high levels of seroconversion to Salmonella Dublin and Neospora caninum amongst the animals sampled. Preliminary examination of the data would suggest that these two pathogens appear to be the most common agents associated with abortion in Ireland at present. Kilkenny diagnosed colisepticaemia and hypoglobulinaemia in two two-day old calves from different herds. Hypoglobulinaemia was also a feature in another calf that had died following a brief period of severe abdominal pain and head shaking. The zinc sulphate turbidity (ZST) test reading was six units (normal readings should be above 20 units), a faecal sample was positive for rotavirus and cryptosporidia, and there was evidence of low-grade meningitis on histopathological examination of the brain. Athlone reported chronic salmonellosis in three calves aged six to eight weeks old. The calves presented with gangrene of the extremities involving ears, tails and legs Figure 2). Salmonella Dublin was isolated from one calf that had not been recently treated with antibiotics. Lungworm infection in a weanling was observed by Dublin. This has been observed in previous winters and serves as a reminder that farmers and practitioners should consider lungworm in their differential diagnoses of respiratory disease, even in December. Athlone and Kilkenny both diagnosed pneumonia in weanling cattle, associated with Manheima haemolytica. Dublin examined two of five weanling cattle, which had died, in a group of 300. At least thirty of the animals had been showing signs of respiratory distress. The animals had recently been purchased and the groups were mixed prior to housing in a poorly ventilated shed. Pasturella multocida was isolated from the lungs of both carcases. Athlone carried out a post-mortem examination on a weanling, which had been treated with a long course of antibiotics for an infection in the head after dehorning. Gross examination showed multiple necrotic foci in the lungs and liver, as well as a large abomasal ulcer. Histopathological examination showed multiple thrombi especially in the lungs. Careful examination of the thrombi showed the presence of fungal hyphae, which is suggestive of a fungal septicaemia. A six-month old weanling examined by Limerick was found to have severe necrotic cellulitis and myositis of the right hind leg, extending from the coronet to the hip. The likely cause was a skin puncture wound found in the region of the coronet. Arcanobacter pyogenes was isolated from the lesion. The deaths over a three-week period of four housed yearling cattle on silage were investigated by Cork. Botulism was suspected based on the clinical signs of flaccid paralysis followed by death. Clinical pathology and necropsy failed to identify other diseases and toxin tests are pending. The herd owner had harvested the silage from rented land on which there are broiler-rearing units. Athlone diagnosed Johne’s disease (Mycobacterium avium subspecies paratuberculosis) in a Charolais bull with a history of chronic diarrhoea and ill-thrift. A positive blood antibody test (ELISA) was followed some months later by a positive faecal culture test. Based on the confirmatory culture result, the local district veterinary office was notified. Sheep Athlone, Kilkenny and Sligo reported parasitic gastro-enteritis and fluke causing ill-thrift and mortality in a number of sheep flocks. Athlone examined faecal samples from an organic sheep flock. The samples showed moderate numbers of strongyle and trichuris eggs, but also very high tapeworm egg counts. Kilkenny found that a six-month old lamb had evidence of a severe dosing gun injury. A large necrotic mass was found in the pharyngeal area, and lesions of pneumonia were also seen. Microabscessation of the spinal cord, suggestive of listeriosis, was seen on histopathological examination. A six-month old lamb examined by Dublin was found to have evidence of malnutrition and cobalt deficiency. The lamb had a history of progressive ill-thrift over a period of weeks. There were a number of other deaths with similar histories in the same cohort group. Samples submitted to Cork from sheep sent for slaughter had evidence of both sheep scab and ringworm. The sheep had clinical signs of pruritus on ante-mortem inspection. Ringworm is considered to be rare in sheep but was recorded previously in Cork (Power, S. B. and Malone, A. (1987) Veterinary Record 121, 218-220). Athlone reported lice infestation (Damalinia ovis) in a sheep flock where scratching and wool loss was a clinical feature. Pigs Kilkenny isolated Streptococcus dysgalactiae equisimilis from the organs of one of three nine-day old pigs with lesions consistent with septicaemia. This pathogen is normally associated with superficial suppurative lesions in pigs. No external lesions were noted. Two 35-day old piglets with a history of enteritis were submitted to Kilkenny. Both showed severe congestive lesions of the small and large intestines, with very watery contents. Escherichia coli 0149 was isolated from both piglets. Other Species Athlone reported on a case of suspected warfarin poisoning in a dog. Material containing cereal grains mixed with a blue chemical was found in the stomach. The diffuse haemorrhages seen on gross examination were suggestive of warfarin toxicity. Athlone reported on the deaths of 22 deer, does and fawns, found in a paddock. Post-mortem examination of one animal showed that the cause of death was cervical fracture. A variety of other lesions such as subcutaneous haemorrhage, skin perforations and abrasions were also described. It was concluded that the animals had been chased and that in their terror and efforts to escape they had killed themselves on the fences and the bushes. Dublin was involved together with Virology Division in the post-mortem examination of five Whooper swans from a larger flock of wild swans from which others were also either found dead or moribund. No acute inflammatory lesions were observed and all tests were negative for infectious viral pathogens. Four out of the five swans had impaction with either forage or some grain of the proventriculus and in some cases the entire oesophagus and gizzard as well (figure 3). Lesions consistent with aspergillosis were observed in the air sacs and lung tissue of one swan. Further investigation into the aetiology (including the possibility of lead poisoning) of these pathology findings was continuing. . CAPTIONS FOR PHOTOS Figure 1 “Microbiological analysis of Bovine Foetal Samples Submitted to the RVLs during December 2005” Figure 2 “Terminal dry gangrene associated with Salmonella Dublin infection in a two-month old calf – photo John Fagan” Figure 3 “Impaction of the oesophagus and gizzard of a swan – photo William Byrne”