Experimental ivermectin treatment of sarcoptic mange and establishment of a mange-free population of Spanish ibex.

Abstract

Ivermectin was used to treat sarcoptic mange in Spanish ibex (Capra pyrenaica hispanica). Its therapeutic effectiveness was analyzed when it was administered through subcutaneous injection, to sick animals in the consolidation stage of mange (third phase) and, with double injections to chronically affected animals (fourth phase) at a dosage of 0.2 or 0.4 mg/kg body weight (bw). Three wk after treatment, the animals in the third phase of mange treated with a high dose (0.4 mg/kg bw) of ivermectin were completely cured. The same result was achieved after 4 wk of treatment in those animals in phase 3 of mange when 0.2 mg/kg body weight was used. Double injection with ivermectin, even at high doses, did not guarantee the complete cure of all cases of sarcoptic mange in the chronic stage (phase 4); only three of six animals were free of Sarcoptes scabiei. The second experiment consisted on the application of a sanitation program in order to obtain a population of Spanish ibex free from S. scabiei, starting with free-ranging animals, some of them healthy and others sick. After capture the animals were classified as chronically ill, in which case they were excluded from the program, mite carriers and healthy specimens. All the animals were treated first topically with foxim (500 mg/l) and subcutaneously with ivermectin (0.4 mg/kg bw). The infected animals were housed in the treatment pen, and received two doses of ivermectin (0.2 mg/kg bw) at an interval of 15 days, then spent 15 days in the quarantine pen, where they received a further dose before they were included in the pool of healthy animals, and immediately were placed in the quarantine phase. The sanitation we implemented was fully effective in curing the affliction of Spanish ibex affected by S. scabiei.