Experimental vermeersiekte (Geigeria ornativa O. Hoffm. poisoning) in sheep. I: An evaluation of diagnostic aids and an assessment of the preventive effect of ethoxyquin.

Dried milled Geigeria ornativa, which had been stored at room temperature for 4 years, was fed in rations to sheep. The usefulness of contrast radiography of the oesophagus, biopsies of oesophageal and skeletal muscles, electrocardiography, and clinical pathological parameters for diagnosing vermeersiekte were evaluated. Ethoxyquin was evaluated as a preventive agent. All the sheep developed signs of vermeersiekte but regurgitation was observed in only one animal. Contrast radiography and the examination of tissue biopsies were of diagnostic value in 8 out of 13 and 6 out of 6 sheep respectively. Electrocardiography did not aid in antemortal diagnosis of the condition and selected chemical parameters were non-specific. The inclusion of ethoxyquin in the diet of experimental animals (n = 3) prior to and during feeding of G. ornativa did not prevent the development of vermeersiekte. This study confirmed that dried stored G. ornativa retains its toxicity and that regurgitation is not a consistent clinical sign in sheep with vermeersiekte. The diagnostic value of contrast radiography of the oesophagus and examination of oesophageal and muscle biopsies is reported for the first time.