Bol S, Caspers J, et al. Responsiveness of cats (Felidae) to silver vine (Actinidia polygama), Tatarian honeysuckle (Lonicera tatarica), valerian (Valeriana officinalis), and catnip (Nepeta cataria). BMC Veterinary Research. 2017;13:70.
The value of environmental enrichment strategies in promoting optimal physical and mental health of pet cats is well-known and evidence-based. These researchers explored the role of olfactory stimulation as a modality of environmental enrichment for cats. Catnip is renowned for its apparently euphoric effect in most cats, but there also anecdotal reports of other plants with similar effects on domestic cats. Much less is known about these other botanicals, what percentage of cats have a positive response to them, or what chemicals they contain that are responsible for triggering enjoyment behaviors in cats. Common big cat species (Pantherinae), except for tigers, also frequently display interest and enjoyment behaviors when offered catnip and similar botanicals.
The 100 domestic cats who participated in the study were randomly selected from animals living in a cat sanctuary, an adoption-guarantee shelter, in private homes, and a cats-only veterinary practice. All cats were six months of age or older, and were classified, based on the observations of staff and volunteers who worked with them, into three different behavioral categories: 1) scared or shy (avoiding humans and hiding); 2) intermediate (showing an interest in human presence and enjoying petting); 3) affectionate or friendly (approaching humans on their own initiative and inviting petting). All cats had been gonadectomized; there were 35 neutered males, 55 spayed females, and 10 cats whose sex was not specified.
The botanicals were offered to the cats either in a thin, porous sock or spread out on a small piece of carpet. Identical empty socks and carpet without plant materials served as negative controls. The cats were exposed to catnip, silver vine, Tatarian honeysuckle, and valerian root in their normal living environment. None of the cats demonstrated enjoyment behaviors when exposed to the control sock or carpet.
Silver vine and catnip were the plant materials that elicited the most positive responses, with 79% of cats responding to silver vine with enjoyment behaviors, and 68% responding similarly to catnip. Significantly fewer cats responded to Tatarian honeysuckle (53%) or valerian root (47%). The response to silver vine was more intense than to catnip. Male and female cats responded in equal numbers to the four plant materials, and no sex differences in intensity of response to the botanicals were detected.
The researchers also found that younger age (< 4 years and 10 months, the median age of the subjects) was not associated with increased responsiveness to the plant materials, although older cats (> 4 years and 10 months) often had milder or partial responses when compared to younger cats. There was also no association between responsiveness and enjoyment behaviors and the cat's behavioral category. The "scared and shy" group responded as frequently and as intensely as the other behavioral groups. No conclusions could be drawn regarding the association between breed and responsiveness to the botanicals, as virtually all of the cats were mixed breed domestic shorthairs.
Almost all of the cats (94/100) responded to at least one of the plant materials, while 6 cats did not respond to any of them, and 23 of the 95 cats (24%) who were exposed to all four botanicals responded to all of them. Most of the cats (71%) who showed no interest in catnip responded to silver vine.
The plant materials were also tested on some big cats: 9 tigers (Panthera tigris; Pantherinae) and 5 bobcats (Lynx rufus; Felidae), living in a sanctuary for exotic cats. For these animals the botanicals were presented in paper bags or uncontained. One of the nine tigers appeared mildly interested in the catnip; the rest showed indifference. Five of the nine tigers appeared to actively dislike the silver vine, backing off and walking away. The other four were indifferent to this plant. Four of the bobcats responded positively to the silver vine, and one liked the catnip.
Nepetalactone is known to be the compound associated with the catnip effect in responsive cats. Six other compounds with similar chemical structure to nepetalactone are present in silver vine, while one of these is present in valerian root. When the plant materials were analyzed using gas chromatography, only the catnip had substantial quantities of nepetalactone; the other botanicals did not contain significant quantities of this chemical. The four species of plants evaluated in this study are generally regarded as safe and nontoxic for cats and humans. Although silver vine is even better liked by cats than catnip, it is expensive and hard to obtain, as it comes only from east Asia.
There are likely to be significant ways in which the use of botanicals such as catnip can contribute to the welfare of cats. Additional controlled studies with substantial sample sizes are needed to verify their effectiveness on a cat's well-being in a variety of situations. Use of plant materials that cats enjoy can increase their playtime and offer activity for cats left at home alone or confined indoors.
In shelters, plant materials can help shy or frightened cats to experience enjoyment behaviors and display playfulness, which has been identified in another study as being a very important factor in the decision of potential adopters to choose a particular shelter cat. Botanicals can also be used for training purposes, socialization, and non-caloric rewards. Catnip may lure feral cats into humane traps as effectively as food, and can be used to support these animals as they undergo a trap-neuter-return process. Plant materials from which cats derive pleasure can be used to support cats in stressful situations such as boarding, transportation, or hospitalization and medical procedures.
Because not all cats respond positively to catnip, it is important for professionals concerned with the welfare of cats as well as cat owners to be aware that other plant materials are available as alternatives to catnip, and many cats who are not interested in catnip may benefit from being offered one of the other botanicals evaluated in this study. [PJS]
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