The chemical signals your cat leaves behind—and how they play an important role in your cat’s relationship with their environment and you.
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| Photo: Scalia Media/Shutterstock |
By Zazie Todd PhD
To some extent feline pheromones are still a mystery—but we know more about them than ever before. Understanding them is one of the keys to understanding your cat’s behaviour.
What are pheromones?
Pheromones are chemical signals, technically called semiochemicals because they have meaning. Cats produce various pheromones and leave them as chemical signals that they or other cats will notice. The one you are most likely to have heard of is the synthetic pheromone in Feliway Classic that is used to help make cats feel at home.
Pheromones are a type of volatile organic molecule, and cats have an innate response to them. In other words, cats don’t have to learn what they are; they are born with the response. Pheromones are used to leave a message, which might be for another cat—but cats will also sniff their own pheromones too. Sometimes the receiver of the message is present, like when cats rub on each other, but sometimes they are not and they receive the message when they come across it at some later time.
How cats detect pheromones
Cats detect pheromones with the vomeronasal organ (VNO). The VNO is two fluid-filled sacs in the hard palate at the top of the mouth. There are two ways that molecules can get there. Molecules in the nose can dissolve in the nasal mucus and enter the VNO via the nasopalatine canal. Alternatively, molecules are licked or breathed into the mouth where they dissolve in saliva. The molecules travel to the VNO via two openings behind the front teeth. Molecules can be pushed out and back into the VNO so it may take cats a little while to process them. The VNO connects to a part of the brain called the amygdala.
It is possible that the olfactory system can also detect pheromones (Tirindelli et al 2009). We know this happens in mice so it’s probably the same for cats.
Cats detect pheromones using something called the Flehmen response. This looks like a grimace and involves lifting the head up, pulling the lips back and putting the tongue towards the front of the mouth. This is the same in all cats and can last thirty seconds or longer. During the Flehmen response, pheromones enter the ducts, and it also helps move pheromones up to the VNO.
Kittens start to show the Flehmen response at 5 weeks of age and it is fully developed by 7 weeks.
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How cats make pheromones
Cats produce pheromones in glands around the body, including between the head and ears, at the side of the lips, under the chin and in the cheeks. Cats also have glands in the pads on their paws, and in the anal and urinogenitary region. Female cats have glands around the teats that produce feline maternal appeasing pheromone.
Pheromones can be deposited into the environment or onto other cats via facial rubbing, tail wrapping, urine spraying, middening (leaving poop uncovered), scratching, and exposure of the glands around the teats.
The social role of feline pheromones
Cats will facial rub against objects in the environment (including furniture and walls) as well as against each other and humans. A team of scientists led by Patrick Pageat has found five different chemical fractions in the pheromones deposited by facial rubbing, known as F1, F2, F3, etc.. While we don’t know what they all do yet, one of them (F2) is associated with sexual behaviour. Another one, F3, is territorial and used to mark objects and places that the cat uses often; the synthetic version of this is in Feliway Classic. F4 is important for social relationships within groups of cats: cats that get on will rub against each other (called allo-rubbing) and also allo-rub the same places. Hence it is thought to create a ‘group scent’.
Tail-wrapping is also thought to maintain a ‘group scent’ and hence social cohesion.
Your cat probably likes to rub their head on you too. It’s a lovely greeting and a sign that they include you as part of their social group. Scientists have also found that cats prefer us to pet them in the places around the head and face where they make pheromones (Ellis et al 2014). (But remember to always give your cat a choice of whether or not to be petted).
Marking cats’ territory
Pheromones also have territorial uses. Head-rubbing, middening and urine-spraying all have this function. Deposited pheromones are still there when the cat is not, and are thought to give information about when the cat was there, their health, sexual status, and so on. There are several hypotheses about how this works.
Urine spraying leaves both visual and olfactory signals. The location of the spraying is likely chosen with care. In wildcats (F silvestris), it has been suggested they choose a particular plant to spray on, common juniper, because chemical properties of the plant will amplify the pheromones.
Middening – leaving faeces in a prominent location – may also make pheromones available to other cats. Barn cats will bury faeces within their own area, but leave them exposed when away from the barn. Research shows cats can differentiate between faeces from familiar and unfamiliar cats, spend longer sniffing that of unfamiliar cats, and get used to the odour of unfamiliar cats’ faeces (Nakabayashi et al 2012).
Scratching is also thought to have a territorial purpose. In one experiment, cats scratched a post significantly more when it had been treated with Feliscratch, a synthetic version of the pheromones found in plantar pads, compared to a placebo (Cozzi et al 2013). So its presence seems to encourage cats to scratch. Because Feliscratch also includes catnip, it’s not known which substance (or the combination) is responsible for this effect (Zhang and McGlone 2020).
Some pheromones are linked to sexual behaviour. In sexually intact cats, males are more likely to show Flehmen behaviour after sniffing the urine or body of intact female cats. The female cat does not do it as much.
Evidence that pheromones are linked to social behaviour comes from a study that found a link between inflammation of the VNO and aggression towards other cats (Asproni et al 2016). They did necropsies on 20 cats. Cats that had inflammation of the sensory epithelium in the VNO were more likely to be aggressive to other cats, but there was no link for inflammation of the non-sensory epithelium. Neither was linked to aggression to humans. This is in line with the idea that pheromones are specific to feline-feline communication.
Pheromone therapy for cats
There are several synthetic pheromones available: a synthetic F3 pheromone, found in Feliway Classic and some other brands; a synthetic Feline Appeasing Pheromone found in Feliway Multicat (also known as Feliway Friends); a synthetic Feline Interdigital Semiochemical available as FeliScratch. More recently, Feliway Optimum contains a new synthetic complex that aims to combine pheromones and work across more situations.
Vets may use an F3 analogue to help cats feel less stressed by having a diffuser in the exam room and spraying towels used to cover cat carriers (Taylor et al 2022). Cat guardians may also be encouraged to spray towels or bedding in the cat carrier with a pheromone spray 15 mins before going to the vet.
Overall, the evidence base for the use of synthetic pheromones to resolve behaviour issues is mixed, and many studies have not used appropriate designs, making it hard to assess the results (Vitale, 2018). One randomized study of Feliway Multicat that used a placebo control group found that it helped to resolve intercat aggression in households with more than one cat (DePorter et al 2018). Another randomized study with a placebo found that a synthetic version of the F3 pheromone can reduce stress in cats when they are temporarily in a carrier (Shu and Gu 2022). However, more research on feline pheromones is needed.
Synthetic pheromones should be used as part of an overall behaviour plan, not used on their own. There seems to be some individual variation in how cats respond, and there’s also a suggestion that the use of catnip might help F3 pheromones work better (although again, more research is needed).
If you’re using a synthetic pheromone, think carefully about where to put it in the house. It should be in a room where the cat spends a lot of their time, and somewhere close to where they rest. If you have multiple cats, you may need several in order to place them where different cats spend time hanging out. You can use catnip, toys, or food placed near to it to encourage the cat to approach where it is and detect the pheromone.
Remember to think about other ways to help your cat too, such as improving the allocation of resources in the home, making extra time for play (especially play with a wand toy), giving your cat food puzzle toys, ensuring your cat has hiding spaces, training your cat, and finding other ways to reduce stress.
If your cat has a behaviour issue, see your vet in case a medical issue is causing or contributing to their behaviour.
Respecting the cat’s sense of smell is one of the five pillars of a healthy feline environment. You can learn more about your cat’s nose and VNO and how to take account of their amazing sense of smell in what your cat’s nose knows.
If you like this post, check out my book Purr: The Science of Making Your Cat Happy. Modern Cat magazine calls it “the must-have guide to improving your cat’s life.” It will be out in paperback on June 6th, and the hardback is available now.
P.S. Don’t miss my webinar How to have a happy cat on May 30th at 10am Pacific (1pm Eastern/6pm UK time). It’s free and a recording will be available to those who register. Closed captions will be available.
References
Asproni, P, Cozzi, A, Verin, R, Lafont-Leceulle C, Bienboire-Frosini, C, Poli, A and Pageat, P. (2016) Pathology and behaviour in feline medicine: investigating the link between vomeronasalitis and aggression. Journal of Feline Medicine and Surgery, 18(2):997-1002.
Cozzi, A., Lecuelle, C. L., Monneret, P., Articlaux, F., Bougrat, L., Mengoli, M., & Pageat, P. (2013). Induction of scratching behaviour in cats: efficacy of synthetic feline interdigital semiochemical. Journal of Feline Medicine and Surgery, 15(10), 872-878.
DePorter, T. L., Bledsoe, D. L., Beck, A., & Ollivier, E. (2018). Evaluation of the efficacy of an appeasing pheromone diffuser product vs placebo for management of feline aggression in multi-cat households: a pilot study. Journal of Feline Medicine and Surgery, 21(4), 293-305.
Ellis, S., Thompson, H., Guijarro, C., & Zulch, H. (2014). The influence of body region, handler familiarity and order of region handled on the domestic cat’s response to being stroked Applied Animal Behaviour Science, 173, 60-67.
Nakabayashi, M., Yamaoka, R. and Nakashima, Y. (2012) Do faecal odours enable domestic cats (Felis catus) to distinguish familiarity of the odours? Journal of Ethology 30:325-329.
Shu, H., & Gu, X. (2022). Effect of a synthetic feline facial pheromone product on stress during transport in domestic cats: a randomised controlled pilot study. Journal of Feline Medicine and Surgery, 24(8), 691-699.
Taylor, S., St Denis, K., Collins, S., Dowgray, N., Ellis, S. L., Heath, S., … & Ryan, L. (2022). 2022 ISFM/AAFP cat friendly veterinary environment guidelines. Journal of Feline Medicine and Surgery, 24(11), 1133-1163.
Tirindelli, R., Dibattista, M., Pifferi, S. and Menini, A. (2009) From pheromones to behaviour. Physiological Review 89:921-956.
Vitale, K. R. (2018). Tools for managing feline problem behaviors: pheromone therapy. Journal of feline medicine and surgery, 20(11), 1024-1032.