Investigating parasite burdens of orphaned greater one-horned rhino (Rhinoceros unicornis) calves, orphaned juveniles and wild rhinos in Kaziranga National Park, Assam, India
AWF Research Fund
Area of study
Every year, rhino calves orphaned by floods in Kaziranga National Park are rescued by staff from the Centre for Wildlife Rehabilitation & Conservation Centre (CWRC). The rhinos are kept there until they are released into a neighbouring national park two to three years later.
This study sought to establish the prevalence of parasite infections amongst these rhinos, and to use it as an indicator of the orphaned rhinoceroses’ overall health and welfare. Three groups were studied: rhino calves at CWRC, juveniles at CWRC and wild rhinos in Kaziranga.
54 faecal samples were analysed for parasite infection, and the results suggest that parasitic infections in these settings is relatively common. However, whilst rates of infection were high amongst orphans, particularly the juvenile ones, the severity of the infections was relatively low. So overall the orphaned animals were in good health.
Recommendations to reduce parasitic rates include targeted selective treatment of highly affected rhinos only (to reduce resistance to treatment in the long run), and to release juveniles earlier in order to reduce the population density and so reduce the number of parasites which thrive in this environment.
There is a dearth of existing literature about the impact of parasites on orphaned rhino and elephant calves. Rhinos and elephants harbour a varied parasite load (Aviruppola et al. 2016). Parasites can have significant effects on their hosts, including slowing growth rates, reducing fecundity and in severe cases, death (Altizer et al. 2013). By understanding the link between parasite burdens and stress associated with captivity, there is scope for better management which may lead to a practical and demonstrable increase in animal welfare.
Blanket use of anthelmintic drugs has led to widespread resistance (Elsheikha & Castro 2015). Targeted selective treatment of parasites can reduce the incidence of drug resistance, which is one of the major challenges being faced in veterinary medicine today. If this study is able to elucidate factors that cause high parasite burdens in rhino and elephant calves, management changes may be able to be made that can better target treatment, which could lead to a reduction in the prevalence of resistant parasites while concurrently improving animal welfare.