Prevalence of equine sarcocystis in British horses and a comparison of two detection methods

Sarcocystis was detected in oesophageal samples from 245 (62 per cent) of 394 horses and ponies killed at a Cheshire abattoir between February and August 1981. Prevalence of infection was closely related to age, increasing from 28.6 per cent of animals up to two years old to 88.9 per cent of those over eight years old. There were no significant regional differences in prevalence between horses from north west England, Yorkshire or South Wales. Significantly more female horses were infected (69.7 per cent) compared with males (56.2 per cent). Gross examination methods detected fewer than 55 per cent of all infections compared with a tissue digest method. Sarcocysts ranged from 1 to 15 mm in length (mean 5.5 mm) and were up to 0.5 mm wide. Cyst wall morphology and bradyzoite dimensions suggest that the species involved is Sarcocystis bertrami (syn equicanis).     

Pharmacokinetics of sulfamethazine in male, female and castrated male swine

The concentration of sulfamethazine in plasma and sulfamethazine and its metabolites in urine were compared in male, female and castrated male swine. A surgical technique for placement of catheters in the urinary bladder was used to facilitate the collection of urine in males and castrated males. The elimination rate of sulfamethazine from plasma and the excretion of parent drug and metabolites into urine did not differ significantly among females, males and castrated male swine.     

Secondary amyloidosis in a bull with Chediak-Higashi syndrome.

A ten year old Hereford bull with Chediak-Higashi syndrome was examined at necropsy after a lifelong history of recurrent bacterial infections. Amyloidosis, which has not been previously reported in Chediak-Higashi, was identified in liver, spleen and kidney.     

Thromboembolic meningocephalitis caused by Haemophilus somnus infection in a bull calf-a new disease in New Zealand

Thromboembolic meningoencephalitis (TEME) caused by Huemophilus somnus infection was diagnosed for the first time in New Zealand in an eight month old bull calf. Clinical signs included pyrexia, excessive salivation, recumbency, opisthotonus and rigidity of the front legs. Multiple red, malacic foci (1-10 mm in diameter) were visible grossly on the surface of the cerebrum and cerebellum, and were scattered throughout the brain parenchyma. Histologically these lesions consisted of focal haemorrhage, necrosis and neutrophilic infiltration. Fibrin thrombi and colonies of gram negative bacteria were present in many small blood vessels within necrotic foci. An organism with the morphological and biochemical characteristics of Haemophilus somnus was cultured from the brain. Although TEME is an important disease of feedlot cattle in North America and Europe it is relatively uncommon in cattle grazing pasture and is therefore unlikely to become a major problem in New Zealand.     

Rickets in yearling steers wintered on a swede (Brassica napus) crop

Rickets was diagnosed in a group of 80 yearling Angus steers wintered for three months on a crop of swedes (Brassica napus) in the Kimbolton area. Growth rate was poor and several steers developed lameness during the final three weeks on the crop. Five animals were euthanased after developing bone fractures. Necropsy of two animals revealed soft ribs, enlarged costochondral junctions and irregularly thickened growth plates in long bones. Histologically there were islands of hypertrophic cartilage within metaphyses and disruption of metaphyseal trabeculae. Thickened, irregular, trabeculae were sometimes lined by wide osteoid seams. Phosphorus deficiency was considered to be the most likely aetiology of the osteodystrophy. The dry matter content of the swedes was only six percent, and in order to satisfy their phosphorus requirements each steer would have had to ingest approximately 330 kg of swedes per day. Rickets is an uncommon disease of grazing animals in New Zealand and to our knowledge this is the first report of its occurrence in cattle.     

Toxicosis in newborn pigs associated with cutaneous application of an aerosol spray containing chlorpyrifos

Weakness, lethargy, ataxia, lateral recumbency, limb paddling, tremors, salivation, and diarrhea were observed in newborn pigs on a commercial swine farm. Many pigs became moribund and died. All had been treated with an aerosol wound spray containing 2.5% chlorpyrifos. A controlled study was undertaken to determine whether the aerosol spray was the cause of these clinical signs. Pigs exposed to aerosol spray containing 2.5% chlorpyrifos at 3 hours (n = 4) and 6 hours (n = 3) after birth developed clinical signs similar to those on the farm; none survived. Pigs exposed at 24 hours (n = 5) after birth developed clinical signs consistent with those that had developed in pigs on the farm; 3 died and 2 survived. Of 3 pigs exposed to the same spray at 36 hours after birth, 1 developed tremors 7.5 hours later and diarrhea 9 hours later, then returned to normal.     

Probable transmission between animals of a plasmid encoding aminoglycoside 3-N-acetyltransferase IV and dihydrofolate reductase I

Ten aminoglycoside-resistant Escherichia coli isolated from the faeces of healthy or diarrhoeic animals reared in the same herd were studied. These strains were resistant to high levels of apramycin and low levels of gentamicin. They were also resistant to streptomycin, tetracycline, trimethoprim and some to ampicillin, chloramphenicol, kanamycin or nalidixic acid. Two strains, isolated from a calf and a lamb, respectively, belonged to the same biotype. All the transconjugants resistant to gentamicin-apramycin were also resistant to streptomycin, tetracycline and trimethoprim. In all cases, these resistances were encoded by plasmids of 100 kb. Analysis of these plasmids by agarose gel electrophoresis after digestion by EcoRI or BamHI revealed their similarity. Hybridization with a 500-bp HpaI insert of plasmid pFE872 was observed with DNA from field strains and their transconjugants, demonstrating the presence on the 100-kb plasmids of the gene coding for a dihydrofolate reductase I. A single plasmid, designated pIP1831, could be observed in identical or different strains isolated from calves or lambs, suggesting the transmission of strains and plasmids between animals of different species.