Abstract

Ninety out of hundred Nubian goats were experimentally infected withTrypanosoma evansi and twenty out of twenty-five camels naturally infected with the same parasite were used in this experiment. Single I / M doses of Cymelarsan were given to four groups at rates of 0.125, 0.25, 0.625 and 1.25 mg/kg. Other four groups were also given the drug via I / M route at rates of 0.125 and 0.25 mg/kg / week for two weeks and daily for 8 days. Three groups of camels were given Cymelarsan in single I / M doses at rate of 0.25, 0.612 and 0.125 mg/kg weekly for three successive weeks. Specimens of different tissues, serum, urine and bile were collected immediately after death or slaughter. A weekly slaughter program 14 days post cessation of the drug for surviving animals was conducted for successive five weeks (two goats/ week and one camel / week).  Total arsenic of Cymelarsan^R residues detected in samples was measured. The concentration of arsenic was increased in serum, urine, bile and tissues of goats infected with T. evansi and given Cymelarsan in single I / M doses (0.125 - 0.625 mg/kg) and gradually returned to normal by the end of the experiment. In the remaining groups arsenic concentration in collected samples did not returned to normal level. In camels, the amount of arsenic in the different tissues, serum, urine and bile returned to normal by day 42 of last cessation of the drug. We conclude that camels tend to excrete arsenic from the body more rapidly than goats.

Key words: Nubian goats, camels, Trypanosoma evansi, cymelarsan, residues (arsenic).