Hepatogenous photosensitisation in Scottish sheep casued by Dicrocoelium dendriticum.

Dicrocoeliosis was identified as the probable predisposing cause of weight loss and hepatogenous photosensitisation affecting half of a group of 14 month-old ewe lambs on a farm on the Inner Hebridean island of Coll. Oral dosing of the ewe lambs with 15 mg/kg albendazole only achieved a 79.2% reduction in Dicrocoelium dendriticum egg count, 21 day post treatment. Thus, this report of dicrocoeliosis differs from the disease that occurs elsewhere, both in the severity and nature of its clinical signs, and in the response of the parasite to anthelmintic drug treatment. These differences could indicate the existence of a genetically divergent D. dendriticum population, which may have evolved within the unique and isolated biotope afforded by the machair on the island of Coll. Better understanding of these factors is a prerequisite for effective and sustainable disease control.

Control of caseous lymphadenitis in six sheep flocks using clinical examination and regular ELISA testing.

In an effort to control the spread of caseous lymphadenitis (CLA) infection, flocks of affected sheep on six holdings were tested serologically at regular intervals using an antibody ELISA with a mean (sd) specificity of 99 (1) per cent and a sensitivity of 79 (5) per cent. Western blot assays to detect antibodies to the phospholipase D (PLD) exotoxin of Corynebacterium pseudotuberculosis were used as a further test when ELISA results were inconclusive. Owners were advised to remove from the flock any sheep that demonstrated clinical signs of CLA or tested positive for PLD by ELISA or western blot. Of the six trial flocks, one was dispersed after only two blood tests, and in another the recommendations for CLA control were not followed and infected animals were retained within the flock. In the remaining four flocks, the testing regimen and other advice enabled the disease to be controlled to such an extent that the appearance of new clinical cases of CLA was effectively halted. This remained the case for up to five years after the end of the trial. In two of these flocks, a small number of seropositive animals were detected at the last flock test). However, on the other two holdings all sheep were seronegative in the final two flock tests, consistent with the complete eradication of infection.

Corynebacterium pseudotuberculosis and its role in ovine caseous lymphadenitis.

Caseous lymphadenitis (CLA) of sheep, caused by Corynebacterium pseudotuberculosis, has been a significant disease in the majority of sheep-rearing regions for over a century. Because of the chronic and often sub-clinical nature of the infection, it has proved difficult to control and prevalence is high in many parts of the world, which in turn leads to significant economic losses for farmers. This review describes the important characteristics of C. pseudotuberculosis and examines the pathogenesis and epidemiology of the infection in sheep. The review also discusses the immune response to infection and describes the methods that have been developed to control CLA, with particular emphasis on the use of vaccination and serological testing.

Monensin toxicity in a flock of ostriches.

A total of 42 birds from a flock of 104 farmed ostriches showed signs of toxicity after the accidental inclusion of monensin in their concentrate ration. The initial clinical signs were muscle weakness and ataxia which progressed to recumbency, dyspnoea and death, despite intensive supportive therapy. The serum activity of the enzymes creatine kinase, aspartate aminotransferase and lactate dehydrogenase was high in the affected birds, indicating significant muscle pathology. Few gross lesions were identifiable postmortem, but widespread lesions of degenerative myopathy were present at the histopathological level. However, these degenerative changes were restricted to the skeletal muscle and there was no evidence of cardiomyopathy in any of the birds examined. The birds were fed a ration which contained 215 to 224 ppm monensin for 13 days. New clinical cases ceased to occur shortly after the withdrawal of the source of monensin, but all the individuals which showed clinical signs of toxicity died or were euthanased on humane grounds.

Corpus luteum hemorrhage. Cause of acute abdominal pain in patients receiving anticoagulant therapy.

Intra-abdominal bleeding from the corpus luteum developed in three women receiving anticoagulant treatment. In one of these patients, no other hemorrhagic manifestations were present. Bleeding from corpus luteum should be considered in differential diagnosis of low abdominal pain in women of reproductive age receiving anticoagulant therapy. The ovary has not been widely recognized as a site of hemorrhage complicating anticoagulant therapy, although abdominal bleeding in this location may be more common than previously thought. Thorough clinical studies are needed to establish the precipitating factors and true incidence of this complication.