Survey of practitioners handling slow lorises (Primates: Nycticebus): an assessment of the harmful effects of slow loris bites

Slow lorises (Nycticebus spp.) are one of six venomous mammals, and the only known venomous primate. In the wild envenomation occurs mainly during conspecific competition for mates and territory, but may also be used as an application against parasites or for predator defense. Envenomation in humans is documented, with the most extreme accounts detailing near-fatal anaphylactic shock. From September 2016 – August 2017, we received questionnaire responses from 80 wild animal practitioners working with Nycticebus spp. in zoos, rescue centres and in the wild. We identified 54 practitioners who had experience of being bitten or were otherwise affected by slow loris venom, and an additional 26 incomplete entries. No fatalities were reported. Fifteen respondents noted that medical intervention was required, 12 respondents indicated no reaction to being bitten (9 of these indicated they were wearing gloves). Symptoms for those affected included: anaphylactic shock, paraesthesia, haematuria, dyspnoea, extreme pain, infection and general malaise. Impact of slow loris bites ranged from instantaneous to long-persisting complications, and healing time ranged from 1 day to >8 months. Extremities, including hands and arms, were mostly affected from the bites. Six of nine species of slow loris were reported to bite, with N. pygmaeus being the most common in our sample. We make suggestions regarding the use of these highly threatened yet dangerous primates as unsuitable tourist photo props and zoo animal ambassadors. We discuss the medical complications experienced in relation to protein sensitisation, and bacterial pathogenesis. We recommend future work to ascertain the protein content of slow loris venom to aid in enabling mitigation of risks posed.