Incidence and risk factors associated with parasitic infections in captive wild mammals and birds in Indian zoos

Abstract

Present study was conducted to record the seasonal incidence and worm burden (eggs per gram of faeces) of helminthic infections and to evaluate the efficacy of deworming protocols followed for control of parasitic infections in captive animals (including birds) at the zoo. Freshly voided faecal samples were collected during winter, monsoon and summer from 150 captive animals including wild mammals (n = 95) and birds (n = 55) between 1–15 years of age kept at Rajiv Gandhi Zoo and Wildlife Research Centre Karaj, Pune (Zoo-I) and Nisargakavi Bahinabai Chaudhary Zoo, Pimpri Chinwad (Zoo-II) in Maharashtra, India. Samples were processed and examined by standard sedimentation and floatation methods to assess the prevalence of helminth infections. Faecal samples of positive animals were collected pre and post-treatment, and the efficacy of the drugs used was evaluated based on faecal egg count reduction test (FECRT). The overall seasonal prevalence of gastro-intestinal parasitic infection in mammals varied among seasons with the highest prevalence (29.50 %) in monsoon followed by winter (26.30 %) and lowest in summer (8.40 %), while the same was found non-significant in birds. Of 19 bird species screened, 25 % of peafowl were positive for Ascardia spp., 25 % of crested eagles for Capillaria spp., and 50% of brown fish owls for Strongyloides spp. Among mammals, 75 % of Black Buck, 50 % of Leopards and 25 % of Giant Malabar Squirrels were positive for Strongyloides spp., while all four Bonnet Macaques were positive for Balantidium coli. The range of eggs per gram (EPG) of faeces recorded was 50–300 in mammals and 100–350 in birds. At Zoo I (Rajiv Gandhi Zoo and Wildlife Research Centre Karaj, Pune), there was 85.89 and 77.36 per cent reduction in egg counts after treatment with fenbendazole @5 mg/kg in herbivores and birds, respectively. While in carnivoresthe reduction was 69.93 % after treatment with a drug combination@10 mg/kg (Praziquantel 50 mg + Pyrantelembonate 144 mg + fenbantel 150 mg). In Zoo II (Nisargakavi Bahinabai Chaudhary Zoo, Pimpri Chinwad) the reduction in EPG was 72.35 % in carnivores with drug combination @10 mg/kg (Praziquantel 50mg + pyrantelembonate 144 mg + fenbantel 150 mg) and 68.98% in birds with albendazole @10 mg/kg.