Effects of essential oils aroma therapy on stress-ladened solitary carnivores: Changes in anxiety-related behavior and cortisol concentration

Aromatherapy is a popular enrichment that reduces stress.  We hypothesize that essential oils positively affect captivated carnivores to cope with stress.  The solitary carnivores, namely, Asiatic Wolf, Jungle Cat, Asiatic Lion, Common Leopard, and Stripped Hyena, were studied for this purpose during the pre-enrichment, enrichment, and post-enrichment phases. The focal monitoring method was used to observe animal behaviors for 384 hours over the 2 months. The carnivores were provided sensory enrichment with essential oils: Lavandula angustifolia, Eucalyptus globulus Labill, Citrus limon Linn, and Mentha piperita Linn. The FGCs evaluated the cortisol levels by ELISA. The Asiatic wolf is found to be the most stressed carnivore among all studied animals. The efficacy order of the oils in reducing stress was found to be Lavender > Eucalyptus > Peppermint > Lemon. The frequency of stereotypic behavior and cortisol levels in these carnivores were significantly reduced with the effectiveness of essential oil. The aromatherapy reduced cortisol level values ranged from 82.6±0.927 to 46±0.707, 155±0.707 to 93.4±0.927, 385±0.710 to 289.2±1.067, 285.4±1.029 to 190±0.709 and 205.4±0.930 to 176±0.708 in Asiatic Wolf, Jungle Cat, Common Leopard, Asiatic Lion and Hyena respectively.  It is concluded that essential oils and aromatherapy help alleviate stress and anxiety and improve animal behavior. Aromatherapy may be applied as short-term sensory enrichment for captive wildlife.