Background: Olfactory stimulation is an often overlooked method of environmental enrichment for cats in captivity. The best known example of olfactory enrichment is the use of catnip, a plant that can cause an apparently euphoric reaction in
domestic cats and most of the Pantherinae. It has long been known that some domestic cats and most tigers do not respond to catnip. Although many anecdotes exist of other
plants with similar effects, data are lacking about the number of cats that respond to these plants, and if cats that do not respond to catnip respond to any of them. Furthermore, much is still unknown
about which chemicals in these plants cause this response.
Methods: We tested catnip, silver vine, Tatarian honeysuckle and valerian root on 100 domestic cats and observed their
response. Each cat was offered all four plant materials and a control, multiple times. Catnip and silver vine also were offered to nine tigers. The plant materials were analyzed by gas chromatography coupled with mass spectrometry to
quantify concentrations of compounds believed to exert stimulating effects on cats.
Results: Nearly all domestic cats responded positively to olfactory enrichment. In agreement with
previous studies, one out of every three cats did not respond to catnip. Almost 80%
of the domestic cats responded to silver vine and about 50% to Tatarian honeysuckle and valerian root. Although cats predominantly responded to fruit galls of the silver vine plant, some also responded
positively to its wood. Of the cats that did not respond to catnip, almost 75% did
respond to silver vine and about one out of three to Tatarian honeysuckle. Unlike domestic
cats, tigers were either not interested in silver vine or responded disapprovingly. The amount of nepetalactone was
highest in catnip and only present at marginal levels in the other plants. Silver
vine contained the highest concentrations of all other compounds tested.
Conclusions: Olfactory enrichment for cats may have great potential. Silver vine powder from dried fruit galls and catnip were most popular among domestic cats. Silver vine and Tatarian honeysuckle appear to be good alternatives to
catnip for domestic cats that do not respond to catnip.