Foot problems, stereotypies and substrate type in Asian elephants: a European survey

Foot problems are very common in captive Asian elephants (Elephas maximus). The purpose of this study was to investigate whether an association exists between floor type, the occurrence of repetitive behaviour and foot problems. For this research project, information about the enclosure floor type, the occurrence of repetitive behaviour and the occurrence of foot problems was collected for adult (older than 11 years) Asian elephants in European zoos, using a brief questionnaire (response rate = 38.09 %). Data on indoor and outdoor housing were pooled for statistical purposes. Information was obtained for 87 adult individuals, out of the 254 adult elephants that are incorporated in the EAZA European Studbook. Most of the elephants had access to areas with sand (87.36 %) or concrete (71.26 %) flooring. A considerable proportion of the animals (72.41 %) displayed repetitive behaviour (stereotypies). The most common type was weaving (37.93 %). The respondents observed foot problems in 59 individuals (67.82 %). Within the latter group, 53 elephants displayed repetitive behaviours, of which weaving was the most common type (34.38 %), followed by nodding (18.75 %) and pacing (15.63 %). The statistical analysis showed that elephants that had access to an enclosure with straw flooring had less chance of displaying stereotypic behaviour than elephants that were kept on other floor types (Prevalence ration (PR) = 0.12; P < 0.01). Elephants partly kept on dirt were less likely to have foot problems than animals standing on other substrates (PR = 0.67; P = 0.01). It was shown that elephants in this study that showed stereotypic behaviour were 337 times more likely to have foot problems than elephants that showed no stereotypic behaviour (PR = 3.37; P < 0.01). However, the results of this study should be interpreted with caution. Adhering to the advice of the EEP coordinator, questionnaire length was restricted and, consequently, certain factors (e.g., distribution of time spent indoors and outdoors, enclosure maintenance, elephant sleeping patterns) were no longer included. Future research elaborating on the development of stereotypic behaviours and foot problems should account for these factors