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Necrotising fasciitis and necrotising myositis are rare but serious life threatening conditions reported mainly in human beings and dogs. Most cases to date have been caused by beta-haemolytic streptococci of Lancefield groups A, B, C or G. Necrotising fasciitis has been reported only twice in cats and necrotising myositis has never been described. This paper describes a fatal case of necrotising fasciitis and myositis with pneumonia and septicaemia in a nine-year-old cat. The cat had been undergoing treatment for a suspected tear of the cranial cruciate ligament, but on the seventh day of treatment it suddenly deteriorated and died. On postmortem examination, there was an area of hair loss from its left hindlimb and discoloration of the underlying fascia and biceps femoris muscle. Severe necrotising fasciitis and myositis, with numerous intralesional Gram-positive coccoid bacteria, was diagnosed histologically. Other findings included necrotising pneumonia, pleuritis, focal encephalitis, myocarditis and nephritis. Culture of the affected tissues yielded a pure, heavy growth of Streptococcus canis.

Pigeon circovirus (picv) was detected in cloacal swab samples by means of a newly-developed, sensitive pcr. An initial investigation of 17 Belgian racing pigeons aged up to eight months showed that rates of detection of 88 per cent and above were achieved using samples of cloacal swab, blood and bursa of Fabricius. The sampling of 15 caged pigeons six times when they were from three to 31 weeks of age indicated that picv infections were more readily detected in cloacal swabs than in blood, and that the virus could be detected in cloacal swabs for longer periods after infection than in blood. picv infections were detected in cloacal swabs from 38 of 47 young pigeons aged from two to 31 weeks, from 12 racing lofts, which had clinical signs including diarrhoea and weight loss, regurgitation and respiratory signs. Samples from birds from two infected lofts indicated that picv could be detected in some birds for at least 27 weeks. Although nine of 14 pigeons aged from 32 to 45 weeks were virus-positive, picv was detected in only one of 18 adult pigeons that originated from four infected lofts.

Nineteen racing pigeons aged from one to five years were examined postmortem. pcr tests showed that the spleens of 16 of them were positive for pigeon circovirus, the livers of six were positive, and blood from one of them was positive for the virus. Five of 44 embryos in embryonated eggs collected from three lofts were positive by pcr, but swabs taken from the crops of 64 adult birds which were feeding one- to 10-day-old squabs in these three lofts were negative for the viral dna.

Two viruses, designated 99-8130(C) and 99-8130(I), were isolated in calf testis cells from the colon and ileum, respectively, of a suckled beef calf which had developed dysentery and died. Electron microscopy indicated that the mean (sd) size of the viral particles, 83 (2.5) nm, and their morphology were consistent with their being members of the family Adenoviridae. They were confirmed as adenoviruses by PCR when products of the expected size (608 bp) were amplified from both isolates by using a primer pair specific for members of the genus Atadenovirus. A comparison of the sequence of a 567 bp segment of the 99-8130(C) amplicon with that of other prototype bovine adenovirus (BAdV) strains of atadenoviruses identified the isolate as BAdV serotype 6 (BAdV-6), which had 99.3 per cent and 100 per cent identities at the nucleotide and amino acid levels, respectively, with the prototype BAdV-6 strain 671130. A virus neutralisation test was developed and indicated a high prevalence of antibody to BAdV-6 in Northern Irish cattle. There was no evidence of adenoviral inclusions in tissues from the affected calf and no antigen was detected when the tissues were stained by an immunoperoxidase technique, using a homologous antiserum raised in rabbits. The two viruses were the third reported isolation of BAdV-6, and the first from a clinically ill bovine animal.

The major causes of leg weakness/lameness were investigated in two male commercial broiler flocks. The numbers of dead and lame birds culled from the flocks each day were recorded by the flock managers. Forty-four lame birds and 22 sound birds were examined postmortem during a period of six weeks and the proximal and distal end of each femur, tibiotarsus and tarsometatarsus were examined histologically. Attempts were made to isolate bacteria and viruses from the proximal end of each femur. Blood samples were examined for antibodies to chicken anaemia virus (CAV), infectious bursal disease virus (IBDV) and Mycoplasma species. Bacterial chondronecrosis with osteomyelitis was identified in the proximal end of the femur of eight of the 44 lame birds, and in the proximal end of the tibiotarsus of a further bird (20.4 per cent). Gram-positive bacteria were present in all the lesions. Staphylococcus aureus was recovered from 62.5 per cent of the lesions confirmed by histology. Bacterial chondronecrosis associated with S aureus has thus been identified as an important cause of leg weakness in these commercial broilers. Lesions suggestive of the condition were visible macroscopically in only 11.1 per cent of the cases subsequently diagnosed by histology and bone histology is therefore required before a diagnosis can be excluded. Angular limb deformities (13.6 per cent) and spondylolisthesis (11.4 per cent) were the most common macroscopic lesions identified as causes of lameness. The overall incidence of tibial dyschondroplasia was similar in both the lame and sound broilers, but severe lesions were found only in lame birds (4.5 per cent).

The role of iodine deficiency in stillbirth/perinatal weak calf syndrome was investigated in pregnant heifers. Five heifers were fed an iodine deficient diet (mean [sd] iodine concentration 0.06 [0.01] mg/kg dry matter [DM]) and six received an iodine sufficient diet (mean [sd] iodine concentration 1.45 [0.27] mg/kg DM). The diets consisted of wheat and soyabean meal with added minerals and vitamins (with or without iodine) and were fed to the heifers over the final four to five months of pregnancy. The iodine deficient diet produced clinicopathological changes and pathological changes in the thyroid glands of both the heifers and their offspring. However, all the calves in the iodine deficient group were born clinically normal.

Data collected from 365 calves dead from stillbirth/perinatal weak calf syndrome were analysed to determine the predictive value of thyroid gland weight as an indicator of abnormality of the thyroid gland, and to examine the relationships between abnormality of the thyroid gland and other findings in the calves and also the parity of the dam. There was a significant relationship (P < 0.001) between the thyroid gland weight and bodyweight for the calves with a histologically normal thyroid gland, but there was no such relationship for calves with an abnormal thyroid gland. Only 1.1 per cent of the histologically normal thyroid glands weighed more than 30 g, indicating that there is a very high probability that glands weighing more than 30 g are abnormal. However, 76.0 per cent of moderately to severely affected glands weighed less than 30 g. The following significant differences between calves with an abnormal and those with a normal thyroid gland were established. Abnormal thyroid glands were significantly heavier (P < 0.01), constituted a significantly greater percentage of the calf's bodyweight (P < 0.01) and had a significantly lower iodine concentration (P < 0.001). A significantly higher proportion of calves with an abnormal thyroid gland had uninflated lungs (P < 0.01), and a significantly higher proportion had pneumonia (P < 0.01). Abnormal thyroid glands were associated with a low selenium concentration in the kidneys. There were no associations between abnormalities of the thyroid gland and the parity of the dam, the presence of skeletal fractures, the weight or sex of the calf, infection with leptospira, Salmonella dublin, Bacillus species, Actinomyces pyogenes or Aspergillus species, the quantities of hepatic iron pigment, liver vitamin E concentration or serum cholesterol concentration.

The isolation, serological classification and growth properties of adenoviruses isolated from fatal cases of haemorrhagic enterocolitis in calves are described. Four viruses, from different submissions, were isolated in cultures of calf testis cells and were identified as adenoviruses by electron microscopy. The four isolates were serologically identical and were classified as bovine adenovirus type 10 in cross-neutralisation tests with other bovine, ovine and porcine adenovirus species. Their growth in the nucleus of infected cells was accompanied by the production of typical adenovirus-associated inclusions. A serological survey to determine the incidence of infection with the virus in cattle in Northern Ireland demonstrated the presence of low levels of neutralising antibodies in 55 per cent of cattle over two years old, although only 8 per cent were positive at a 1/500 dilution of serum.

Microbiological, biochemical and pathological data collected from 293 calves which were either stillborn, or born alive and either failed to breathe or failed to breathe for more than about 10 minutes are presented. No bacteria were recovered from 96 of the calves (32.7 per cent), and bacteria which were considered significant were isolated from only four (1.4 per cent). Evidence of leptospiral infection was found in 75 calves (25.5 per cent). Of 64 calves examined for bovine virus diarrhoea (BVD) and infectious bovine rhinotracheitis (IBR) antigens, two were positive for BVD virus and none for IBR virus. The mean (+/- sd) liver vitamin E and kidney selenium concentrations, determined in 148 of the calves, were 2.0 +/- 0.76 micrograms/g wet matter and 0.47 +/- 0.17 micrograms/g wet matter, respectively. The thyroid iodine concentration in 15 of 71 calves (21 per cent) was less than 300 micrograms/g wet matter and the mean (+/- sd) thyroid weight of 266 of the calves was 18.5 +/- 11.6 g. Evidence of severe trauma was found in 19 of the calves (6.5 per cent). Histological findings included thyroid epithelial hyperplasia, hepatic haemosiderosis, erythrophagocytosis in the spleen, perivascular haemorrhage in brain and adrenal glands, and accumulation of leucocytes in blood vessels.