[Reproducibility of emesis by orally administrated copper sulfate in cats]

Adult cats were administered oral threshold doses of copper sulfate every week. As the cats vomited in 70 out out 80 cases, the reproducibility was 88%. Peripheral vomiting threshold dose was 40 mg/head or less, while the threshold dose for oral copper sulfate emesis after T4 transection and vagotomy was more than 160 mg/head. The following method is thus proposed for application in evaluating an antimetic for oral copper sulfate. Adult cats are to be given the emetic once a week. The threshold dose should be determined in three dose levels; 10, 20, 40 mg/head. The cats with a threshold of more than 40 mg or latency of less than 5 min or of more than 45 min are to be excluded. Inhibition of emesis or a considerable prolongation of latency is the sign of an antimetic action. A positive action of an antiemetic must be followed by another test with the threshold dose of copper sulfate alone. If the cat does not respond to the threshold dose after 2 administrations, the case must be excluded. It is considered positive when 3 cases are inhibited among 4 or more than 50% among more than 5.