A combined treatment regimen for Trichuris rhinopiptheroxella infection in Rhinopithecus roxellana in southern China

Abstract

The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is an endangered species in China and is susceptible to infection with Trichuris species. However, the worms are difficult to remove completely. A practical treatment regimen for trichuriasis was conducted over a seven-month period on 15 R. roxellana in a wildlife zoo in southern China. Initially, a combination of fecal examination, morphological observation, molecular identification of ITS1 and mitogenome, and infective pattern analysis revealed that R. roxellana was susceptible to Trichuris rhinopiptheroxella. Three rounds of treatment were administrated, with a dosage of 10 mg/kg albendazole or ivermectin in each. The initial administration of albendazole to 15 monkeys resulted in a reduction of fecal eggs per gram (EPG) by 7.8%–73.2%. The subsequent administration of albendazole to 9 monkeys demonstrated a reduction in fecal EPG by 52.6%–52.8%. The third administration of ivermectin to 5 monkeys resulted in a reduction of fecal EPG by 55.6%–96.6%. However, the EPG level increased in some monkeys after one month of these three anthelmintic administrations. Subsequently, improved strategies were implemented, including an increased dosage of albendazole, flame sterilization, the replacement of the sandy floor with concrete, and the hanging of food. Results showed that a reduction in the fecal EPG of 8 monkeys in the exhibition region, with a decrease from 5135 to 63. Additionally, 6 monkeys exhibited a negative EPG after one month. In the breeding region, the fecal EPG of 7 monkeys decreased from 7389 to 869. Additionally, 2 monkeys demonstrated a negative EPG after one month. This study provides evidence for the control of Trichuris infection in R. roxellana and offers a guideline for the treatment of trichuriasis in animals.