The clinical effects of dimethyl sulfoxide in sheep suffering from experimentally induced heartwater

Abstract

The objective of this research project was to evaluate the clinical effect of Dimethyl sulphoxide in the symptomatic treatment of sheep suffering from heartwater caused by lichia ruminantiumforrmerly Cowdria ruminantium). 32 Merino crossbred sheep were used of which, 16 were infected with heartwater and 16 were control animals. Of the 16 sheep infected with heartwater, 8 were treated with a 10% solution of DMSO in polyionic fluid at the dose rate of 1g/kg twice daily for three consecutive days. Treatment was initiated two days after the onset of clinical disease. Eight of the control sheep were treated with DMSO following the same protocol. The remaining 8 infected and 8 not infected sheep were given similar volumes of polyionic fluid as placebo treatment. Arterial and venous blood samples for blood gas, haematocrit and total plasma protein measurement were collected daily from 5 days before, to 7 days following the onset of clinical disease. Gross pathological findings and cytological confirmation of the disease were recorded for the 16 infected sheep. The infected sheep treated with DMSO were able to maintain pulmonary gas exchange, had reduced pleural effusion and plasma protein loss compared to the untreated infected sheep that became hypoxic, developed severe pleural effusion and plasma protein loss. However, the infected sheep treated with DMSO developed a mild uncompensated metabolic acidosis. Non-infected sheep treated with DMSO showed reduced appetite while non-infected untreated sheep remained normal. The reduction in pleural effusion, maintenance of gaseous exchange and plasma protein levels, as a result of the use of DMSO in the symptomatic treatment of sheep suffering from heartwater, are considered beneficial.