This month, iCatCare’s feline wellbeing panel member, Dr Lauren Finka discusses her recent published research.
They say a picture paints a thousand words, but when it comes to our notoriously enigmatic felines, is this really true? Just like their closest ancestors (the African or near-eastern wildcat), our domestic cats come fully equipped with some impressive biological functions that enable them to do much of their communicating ‘in absentia’. For example, cats possess special skin glands located over various parts of their body. These glands are able to secrete semiochemicals (chemicals that contain important messages) which they deposit within their environment when they scratch or rub against things, spray urine and even when they deposit their faeces. These special chemical signals are left for other cats to find and decode, which they do using a specially adapted organ located in the roof of their mouths (known as the ‘Jacob’s or vomeronasal organ’). As cats’ closest ancestors are mostly asocial, many of these chemical messages have been designed to help them steer clear of each other (unless mating might be on the cards of course!).
During the course of the cat’s domestication, we have vastly altered their physical appearance, creating the diverse range of modern cat breeds that we know today. What we haven’t done however, is intentionally try to breed cats in order to improve their social skills. The consequences of this are, that whilst many of our pedigree pet cats might look a lot different from their ancestors, they might not be all that dissimilar on the inside. While our cats have been gifted these great signal-at-a-distance capabilities, they haven’t necessarily inherited the ability to communicate complex messages when in close proximity to others, for example via their behaviour and body language. And what if, rather than breeding cats to be better communicators, we’ve actually (unintentionally) done the opposite, by changing their looks in ways that make them even harder to ‘read’?
The science has already made it clear to us the potential downsides of indulging in our desires to create what we consider to be the perfect looking feline. Indeed, some cat breeds are much more likely to suffer from chronic health complaints, due to the specific genetic mutations they inherit, or simply because the physical alterations to their bodies make normal activities much more difficult for them to perform. For example, the cartilage abnormalities that give the Scottish fold their characteristic ‘folded’ ears also cause them to suffer from painful joint problems and arthritis. Additionally, the very flat, disproportionate faces of brachycephalic cats such as the Exotic short hair or modern Persian may cause issues with their eyes and breathing. iCatCare has a strong position when it comes to breeding cats – no harm is done – and for this reason, does not condone breeds with physical features that impact negatively on their welfare.
My recently published research has provided some initial evidence to suggest that these breed related issues might not only affect cats’ physical health, but also their ability to express themselves and communicate via their face. Facial expressions are an important method of communication for many animal species. Such expressions can be used to signal individuals’ intentions or underlying emotions. Even in the case of the often stoic, domestic cat, research tells us that their facial expressions can indicate when they are in pain, fearful, frustrated or comfortable. As owners and carers of cats, we will generally be very aware of the different facial expressions our cats’ display. Some of us will also have a good idea about how our cats or those in our care are feeling, or what they want, based on how their face looks at a given time. However, previous research suggests that in general, when humans are presented with the faces of unfamiliar cats, we can really struggle to correctly identify if the cats in question are in a positive or negative emotional state. Interestingly, the research was limited to domestic shorthaired cats, so this task might become even more difficult when people are presented with cats that have very different looking faces, such as the elongated face of the Oriental short hair cat, or the flattened, condensed face of the Exotic short hair, particularly where individuals have limited experience of cats with such face shapes.
My recent study investigated how the facial features of cats have been altered due to intense selective breeding, and the impact this might have on their ability to clearly display different facial expressions and emotions.
The study was carried out as part of my research at Nottingham Trent University and involved several co-authors from Nottingham Trent University, UK, University of Lincoln, UK and São Paulo State University in Brazil. The results were published in December 2020 in the open access journal ‘Frontiers in veterinary science’.
What did the study do?
For this study, I focused on the faces of cats across nineteen different common cat breeds including the Persian, Bengal, Norwegian forest cat, Egyptian mau, Devon rex and Scottish fold to name a few. I obtained approximately 100 pictures for each breed, only selecting an image if the cat appeared to have a ‘neutral’ facial expression. This was so that when I compared face shapes across the breeds, I could identify differences in their appearance caused by selective breeding, rather than differences caused by a particular emotional state they might have been expressing at the time the picture was taken. I then began the painstaking task of measuring their faces. To do this, I manually placed 48 dots on each image, each dot corresponding to the location of underlying facial muscles. Using a special analytical technique called geometric morphometrics, I was then able to quantify how the locations of these facial points changed across the neutral faces of cats from the different breeds.
In theory, changes in the locations of these dots should indicate when the cat is displaying a particular facial expression, because we know how each of the muscles the dots are linked to contracts and changes the shape of the face during this process. However, because in this case, all the cats appeared to have ‘neutral’ expressions, if these dots showed significant differences in their locations across the different breeds, this tells us something quite important. What this would mean is that when different breeds actually do display different facial expressions, it is unlikely that we would be able to clearly identify them, because there is simply too much variation in the general appearance of cats’ faces, even when no expressions are present. In other words, the expression on the cat’s face when experiencing fear or pain in one breed, might look the same as the expression on a cat’s face when they are relaxed or contented in another breed.
To test this hypothesis, I conducted a second study where I measured the degree to which the facial features of each cat breed corresponded to features we know are associated with the expression of pain in domestic shorthaired cats (for example narrower ears positioned further apart, narrowed eyes and the nose and mouth positioned closer together). I could then compare how much the faces of each breed appeared to show ‘pain like’ expressions, compared to faces of domestic short haired cats which were actually in pain (due to a routine neutering surgery).
Where did all the pictures of cats come from?
The photographs of the different cat breeds were from online sources such as google. In this instance, looking at pictures of cats on the internet was literally my job for several months!
I extracted the images of domestic shorthaired cats in pain from videos previously taken of a population of female cats during neutering at a veterinary clinic in Brazil. These cats were part of a previous study to support the development of a composite acute pain assessment scale, aimed to help veterinarians more accurately assess pain levels in cats and provide them with the right amount of pain relief. All cats received pre-surgery analgesia and then more pain relief post-surgery. The videos where cats were deemed to be ‘in pain’ were taken just before they received their second dose of analgesia
What were the main findings of the study?
As predicted, all of the facial points that I measured varied significantly based on the breed of the cat. This highlights how selective breeding has altered cat’s faces in ways that might make communication and expression more difficult for certain individuals.
Interestingly, the analyses also indicated that certain breeds had neutral faces containing ‘pain-like’ expressions, even though they weren’t actually in pain (as far as it was possible to ascertain). This was particularly true for breeds with rounded, flattened faces (also referred to as ‘brachycephalic’). These brachycephalic cats had greater pain-like expressions on their faces compared to breeds with more proportioned features (e.g. ‘mesocephalic’ faces) as well as compared to breeds with elongated faces (e.g. ‘dolichocephalic’ faces).
In the case of the (brachycephalic) Scottish fold, their neutral faces appeared to show more ‘pain like’ features, even compared to the population of domestic shorthaired cats that were actually in pain!
Why is this study useful?
This study helps to raise the important issue of how our selective breeding of cats might not only impact negatively on their physical health, but also on their ability to clearly express themselves and communicate. For example, if the faces of certain breeds such as the Scottish fold look like they are permanently in pain, this might make it much more difficult for owners or vets to actually detect when pain is or isn’t present. In this case, it may be much more useful to focus on other aspects of the cat’s behaviour and posture other than their face. However, not only has selective breeding changed the appearance of cats’ faces, but also the shape of their general bodies and length of their legs and tails. It is therefore likely that differences in these features will also impact on cats’ abilities to communicate clearly. For example, take the classic ‘Halloween cat’ posture (i.e. legs fully extended, a highly arched back and large poofed-up tail) that cats display when they want to look as big and threatening as possible. This posture may be much easier for a well-proportioned domestic shorthaired cat to display, compared to a Munchkin cat with very short legs, or a Manx cat that doesn’t even have a tail.
However, much more research is needed to now try to understand how these general appearance differences across breeds might impact on cats’ abilities to clearly express themselves, as well as our, and other cats’ ability to understand them.
What does this mean for me and my cat?
Most of us will have a strong desire to understand our cat’s emotions and identify their needs as much as we are able. In multi-cat households, we will also want our cats to get along well with each other. What this research suggests is that we not only need to think carefully about the types of health conditions certain breeds might be more prone to, but also how their physical appearance might limit how easily they are able to communicate, both with us and with other cats. This research suggests that we may have inadvertently selected certain breeds (i.e. those with brachycephalic faces) to look like they are in pain, even when they’re not. The reason we might find these sorts of facial appearances ‘cute’ or appealing is that they may look more vulnerable or needy. This may then motivate us to want to care for and protect them, even when they don’t actually need it. The downside for our cats is that they may receive unwanted attention from us when they might just prefer to have some peace and quiet. Or equally, when they are actually in pain or distressed and do need our help, will we be able to tell? The appeal of these features may also encourage owners to choose these breeds over other healthier types that don’t suffer from health problems related to their conformation. Such cats might also struggle more to communicate with each other, which could lead to less harmonious multi-cat homes. From a welfare perspective, avoiding purchasing cats that have been intensively bred, including those with more extreme, disproportionate features is recommended.
Dr Sarah Ellis, Head of Cat Advocacy here at iCatCare asked Lauren a few extra questions about her research as the results were really fascinating and we were keen to hear where she may go next in this area….
Could the Scottish folds with the neutral faces actually just be in pain given that we know that the genetic abnormality they suffer from can cause pain in their joints?
Lauren: Yes, absolutely – we would next need to look at differences in their expressions associated with specific pain/no pain diagnoses and when given analgesia to try to understand how much their facial expressions actually differ across these contexts (if at all)
Have you plans to compare the faces of the pedigree cats you studied (in neutral) in emotional states such as pain and comparing these to the face types of domestic shorthairs in a neutral expression and when experiencing pain?
Lauren: This would be a great future study although the difficulty is that (ethically) obtaining sufficient data on different pedigree cats in pain is practically very challenging, having previously tried to do just this! However, if any vets/nurses out there could help and would be willing to collaborate then do get in touch!
Another downside to the face types potentially appearing needy is that more people may select these breeds raising their popularity which is a problem when they suffer welfare problems.
Lauren: Yes exactly, so we really need to raise awareness about the physical and social problems these breeds may face and the associated compromises to their wellbeing, so that owners can make better more informed choices regarding cat acquisition and breeders better choices about the cats they decide to breed
Where will the results of this research take you next? Any plans to continue researching this fascinating area?
Lauren: I have a potential PhD candidate that will (hopefully) be looking at how the expressions of cats (and dogs) faces change across positive and negative contexts and if this is consistent across different face types (i.e. brachycephalic [shortened face], mesocephalic [proportioned face] and dolicocephalic [elongated face]) and if face type impacts on human discrimination between these contexts. Another question we will hopefully ask is whether having more extreme facial features impacts on the other ways individuals may behave and attempt to communicate.
Sarah: Such a fascinating study Lauren. Thank you for sharing. If you work in the veterinary profession and are able to help Lauren with acquiring photographs of pedigree cat faces, do get in touch with her at firstname.lastname@example.org.
Finka, L. R., Luna, S. P. L., Mills, D. S., & Farnworth, M. J. (2020). The application of geometric morphometrics to explore potential impacts of anthropocentric selection on animals’ ability to communicate via the face: the domestic cat as a case study. Frontiers in Veterinary Science, 7, 1070.