Tag Archives: cat behavior

Has your cat or dog ever had to wear a “cone of shame”? Also known as an Elizabethan collar (or an E-collar), and resembling more of a lampshade, these devices are routinely prescribed by veterinarians to prevent our pets from scratching themselves, biting at sutures, or otherwise harming themselves.

Apparently the term “cone of shame” was popularized by the movie “Up” – perhaps referring to the fact that it likely feels like a punishment to the wearer. It’s no walk in the park for the pet owner either – turns out that owners are reluctant to use them on their pets, and do not use them for the full length of time recommended by their vet. Cones may even be dangerous, with at least two dogs dying due to getting tangled in plastic bags while wearing the collar.

A recent open-access study out of Australia (“The Cone of Shame”: Welfare Implications of Elizabethan Collar Use on Dogs and Cats as Reported by their Owners) surveyed pet owners with cats or dogs who had needed an E-collar in the last year, asking several questions about why the collar had been recommended, how long the pet had to wear the collar, and whether the owner had observed problems or signs of stress in their pet. There were 434 participants, primarily from Australia. They reported that their pet had a wear the collar for anywhere from 3-7 days.

More than half of owners reported welfare concerns related to the use of the collar: 60.2% said the collar interfered with drinking, and 67.5% reported that their pet was unable to play while wearing the collar. A quarter of pets experienced (mostly minor) injuries from wearing the collar such as itching, trauma, or bumping into walls or objects. Almost of quarter of animals were able to remove the collar on their own, but their owners were helping them out too: over half of owners just took the collar off their pet when they were supervising them.

My cat, "depressed" and coned.

The majority of owners reported that their pet had a worse quality of life while wearing the cone, and reported that their pet was “depressed”, had difficulties eating, and that the distress was worse than the behavior it was supposed to prevent. In some cases, the cone didn’t fit well, and some animals could not jump or walk normally when wearing them.

On the plus side, owners did feel that the cone of shame was effective at preventing the behavioral responses such as licking or biting. It is possible that some cats and dogs could be trained to habituate to and accept wearing a collar, but that is not the approach that most owners can take – the collar needs to go on NOW, not after the pet has been sensitized to it.

I had my own experience a few years ago with the cone and my cat. She was limping, so we took her to the emergency vet. She was diagnosed with “lameness” (okay, it still makes me chuckle) – just a soft tissue injury -- and sent home with pain killers and a cone. Why the cone? I still don’t know. She hated it, and like many pet owners, we did not comply, and we took it off her after just a few hours of her misery. She recovered just fine.

So is the cone of shame a necessary evil? Is it necessary at all? Are there other options? I decided to throw some questions at one of my favorite experts when it comes to medical care for cats, Ellen Carozza, LVT, who works at the Nova Cat Clinic in the DC area. She has specialized in feline medicine for almost two decades, and trust me, this woman knows her sh*t. But I also knew from previous conversations with her that she shared some of my concerns about the routine use of the cone of shame.

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Why did your clinic stop the routine use of e-collars?

EC: We noticed it caused more stress to the patient when they wear them.  When a patient is properly pain managed using a multimodal method, we have found they will not pick or groom the suture area. We barely have external sutures – we do internal and subcutaneous or subcuticular to minimize the picking as well.

 The main complaints we get from clients on e-collars is that the cats won’t eat, they bonk into the walls, become depressed and overly groom the e-collar (that is a indication of pain…they just can’t get to the spot but trying to groom it sure does help!). These cats may also not rest well due to the collar propping their head and face up, so that adds to the discomfort and now the animal can’t get comfortable and sleep. And sleep and rest is very important with the healing process. 

Using a local block, opiates, Gabapentin and NSAIDS (if the kidneys will allow it) along with complimentary therapies such as laser and the Assisi Loop aid in healing because the pet is kept comfortable and the acute and chronic pain is diminished and kept to a minimum. 

Why do most veterinary clinics continue to rely on the “cone of shame”? 

EC: They believe they really do help. What we should be focusing on is pain management to prevent them from wanting to pick at the first place. It is also taught that this is the standard of medicine: just stop the behavior. You also have the " We've always done it *insert excuse of the day here.* 

You can't always trust the owners to keep the area clean and dry.  Most clients don't even check incision sites daily.  So putting a collar on the animal prevents the client from having to do an extra job as a pet parent and pay attention. 

What are the alternatives? Is it time to end this "shameful" practice?

EC: There are lots of alternatives. Some of the newer "cloud or balloon collars" allow the animal to eat more freely, but don't allow the head to rest properly either as it’s an inflatable ring. The "No Bite" collars are neck braces that prevent the neck from bending back to function normally. Some companies go as far as making ridiculous, yet cute e-collars that resemble flowers or lion manes so something so "shameful" isn't (clever marketing). OR the best thing ever is to PROPERLY PAIN MANAGE!!! and address any underlying obsessive behaviors with mood modifying drugs and environmental changes (especially the cats who just clean obsessively and you can't find the reason why medically).

Do I think it's time to end the "shameful" practice? I think it's time for better pain management, behavior and environmental modifications to be done to limit the routine use of them in practice. Understanding the feline pain body scoring allows you to stay ahead of the issue at hand and not have to rely on a cone to suddenly halt a behavior. 

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Hopefully this research will help increase awareness that e-collars are not necessarily necessary or helpful to maintaining companion animal welfare while helping them heal. People hate ‘em, our pets hate ‘em, it’s time to start taking the alternatives seriously!

References

Shenoda, Y., Ward, M. P., McKeegan, D., & Fawcett, A. (2020). “The Cone of Shame”: Welfare Implications of Elizabethan Collar Use on Dogs and Cats as Reported by their Owners. Animals, 10(2), 333.

Shumaker, A. K. (2019). Diagnosis and treatment of canine acral lick dermatitis. Veterinary Clinics: Small Animal Practice, 49(1), 105-123.

Wilson, S. (1993). Elizabethan collars and plastic bags. The Veterinary record, 132(26), 664-664.

The goal for any animal shelter is to keep animals there for the shortest time possible, and help them get adopted as quickly as possible. Understanding what factors might impact “length of stay” (LOS; how long it takes animals in shelters to get adopted) can help shelters allocate resources, promote animals, and also focus efforts on ways to level the playing field, such as through behavior modification or adoption incentives.

A new study looked at whether the behavior of cats was a factor in determining how long it takes to get adopted, with a specific focus on what the researchers labeled as socialization. The study, “The influence of degree of socialization and age on length of stay of shelter cats” was recently published in the Journal of Applied Animal Welfare Science. The researchers had adoption staff of 31 animal shelters assign recently adopted cats one of three socialization levels: interactive (approaches, allows petting, purrs or meows at potential adopter), approachable (not aggressive, may allow handling, not playful), or unapproachable (hiding, running away from potential adopters). Data for a total of 645 cats who were at least one year of age was collected. They also included the age of the cat in the analyses, and looked at the effects of socialization category and age on how many days the cat stayed in the shelter.

Cats in the study were housed in shelters for an average of 55 days, although the median length of stay was only 25 days. The median is the value at which half of the sample is below that value, and half is above. So 50% of cats stay at the shelter for fewer than 25 days, and 50% stay longer than 25 days. Because the average is higher than the median, that tells us that a small number of cats are staying for a very long time, and in fact, the longest length of stay reported before adoption in the study was 1010 days.

Older cats take longer to get adopted. Photo by Dilara Goksel Parry.

Results suggested that both age and behavior impacted how long it took cats to get adopted. For each additional year of age, it took cats an average of 3.7 more days to get adopted. There was also a large effect of behavior category on LOS. Interactive cats were adopted in an average of 36.9 days, but approachable and unapproachable cats took much longer – for approachable cats, the average time to get adopted was 50.8 days, and unapproachable cats were in the shelter for 118.7 days on average. But older cats in the unapproachable category stayed on average even longer – another 14 days for each additional year of age.

One potential weakness of the study is that multiple shelters participated in the study and were asked to categorize cats according to the provided descriptions. It is unknown how accurate these categorizations were, or whether raters would have high levels of agreement when assessing the same cat. If we assume that most shelters were able to determine whether cats were interactive, approachable or unapproachable, then we can agree that indeed, age and behavior are important to determining how long cats stay in shelters.

Now MOST cats in shelters (57%) fit into that first “interactive” category, with 32% in the approachable category and 11% in the unapproachable category. But being scared almost doubles a cat’s length of time in a shelter, and actively hiding leads to an LOS of over three times that of an interactive cat.

Animal shelters should be temporary housing for homeless animals. Animals in shelters experience significant stress and a longer stay increases the risk of illness. Animals who stay in shelters for long periods of time can be a drain on shelter resources and may also prevent other animals from being placed for adoption due to lack of space. So what to do with this newfound knowledge?

Giving shy cats a safe place to hide may help them cope and improve. Photo by Dilara Goksel Parry.

I think the important takeaway from this study is that given the challenges of getting shy and fearful cats adopted in a timely manner, we need to figure out the best ways to help those cats do BETTER in shelters. This could mean changes to housing, such as providing better hiding spaces and giving scared cats quieter spaces so they can decompress and de-stress. It could also mean actively training cats to be more comfortable in their environment, rewarding cats through clicker training or similar methods for positive behaviors. Shelters could focus some efforts on fostering scared cats in homes temporarily to attempt to socialize them, perhaps returning them to the shelter as more “adoptable.”  

References:

Brown, W. P., & Stephan, V. L. (2020). The influence of degree of socialization and age on length of stay of shelter cats. Journal of Applied Animal Welfare Science, 1-8.

Tanaka, A., Wagner, D. C., Kass, P. H., & Hurley, K. F. (2012). Associations among weight loss, stress, and upper respiratory tract infection in shelter cats. Journal of the American Veterinary Medical Association240(5), 570-576.

Vinke, C. M., Godijn, L. M., & Van der Leij, W. J. R. (2014). Will a hiding box provide stress reduction for shelter cats?. Applied Animal Behaviour Science160, 86-93.

 

 

 

A new study compares cats who spray with those who urinate outside the litter box…and their feline housemates.

As I like to say, nothing sends cats to the pound quicker than urine around the house…whether it’s in the form of spray on the wall, or puddles on your carpet, it’s no fun for anyone. The functions of spraying are believed to be different than those of urinating, and cats who spray may continue using their litter box. However, there’s still a lot we don’t know about the motivating factors related to both behaviors, and although we can never read your cat’s mind, we can try to make some educated guesses about why they spray or urinate outside the box. We can also ask research questions that help us better understand what’s going on, which is exactly what a recently published study has attempted to do.

Cat spraying in their home, as captured on webcam.

In “A Case-Controlled Comparison of Behavioural Arousal Levels in Urine Spraying and Latrining Cats”, researchers compared the behaviors and stress levels of otherwise healthy cats who were either spraying or urinating (“latrining” as the authors call it) in the home. They also matched each cat with a case-control – meaning a non-house soiling cat of approximately the same age and the same sex (when possible), from the same household. This study design controls for the effect of different households, because the cats will have the same environment, the key difference being that one of them is house soiling, and the other is not.

The researchers were able to match 11 spraying “dyads” – the sprayers were 2 females and 9 males, and the control cats were 6 females and 5 males. Eight of the households had at least some outdoor access. There were 12 latrining “dyads” – 10 female cats, and 2 male urinators, with 7 female and 5 male control cats. Five households had access to an enclosed yard, and the remaining cats were indoors only. All cats in the study were neutered.

To measure stress, researchers looked at cortisol levels in all of the cats’ poop (fecal cortisol metabolites). Cortisol is a hormone released by our adrenal glands that is often used to measure stress levels. Measuring cortisol from poop has been validated in previous studies and is considered a non-invasive way to detect stress (by a scientist whose last name is Schatz, I kid you not, or maybe I am just easily amused). Owners were given equipment and careful instructions on poop collection.

All cats also came to the veterinary hospital for a behavioral test. The cat’s carrier was placed on the floor of an exam room. Each cat was offered a bowl of food and was allowed to explore the room as they wished while their owner sat nearby quietly. The sessions were video recorded for later analysis of common signs of stress – such as tendency to hide, their body language, their activity levels and how much they meowed.

The experimental set up for the behavioral test. Picture from Ramos et al., 2020. https://www.mdpi.com/2076-2615/10/1/117

Results indicated no difference between the cortisol levels of sprayers with their matched control housemates (~500 ng/g). But both cats in each spraying dyad had higher levels of cortisol in their poop compared to latriners and their housemates (who were also similar to one another; ~400 ng/g). There were few behavioral differences among the cats, the most notable difference being that the cats from spraying households were more active during the behavioral test.

This study is very interesting because it suggests that cats living with other cats may be affected by the presence or stress of those other cats. However, the cat who is spraying or latrining is not necessarily MORE stressed out than their housemates. Instead, they’re all stressed – and it could be the spraying behavior that is elevating the stress levels of other cats in the home!

So why do some cats express that stress as house soiling? This is a question that merits further exploration – it could be a personality trait, a coping mechanism, a genetically mediated behavior, or something else! From this research, we can determine that spraying is likely associated with higher levels of stress; and in fact, other studies of cats’ fecal cortisol levels (where cats did not exhibit house soiling) have suggested much lower levels in the range of ~200 ng/g. The relationship between latrining and stress is less clear, although latrining cats still had much higher cortisol levels compared to the cats in previous studies.

A few other important observations from this study: the spraying households had on average six cats, and latrining households averaged 4.6 cats, suggesting that the number of cats in the home may directly contribute to both stress and spraying behavior. Previous studies have not found that cats in multicat households necessarily have higher stress levels than single cat homes. Access to the outdoors also did not seem to be a protective factor for spraying – most households with spraying gave their cats outdoor time.

This research does point to the importance of managing stress in households where spraying is present. Although we cannot determine if stress led to the spraying, or spraying is causing the stress, we can conclude that once spraying is present, stress is present, and a treatment plan is necessary. Treatment for spraying often includes increasing resources and distributing them throughout the home, addressing relationship issues between cats, increasing mental stimulation and play and promoting safety and choice for cats. My professional experience has been that many sprayers also benefit from anti-anxiety medication – and perhaps future research could explore whether or not placing a sprayer on anti-anxiety medication can reduce the fecal cortisol of both the sprayers and their housemates!

References

Ramos, D., Reche-Junior, A., Luzia Fragoso, P., Palme, R., Handa, P., Chelini, M. O., & Simon Mills, D. (2020). A Case-Controlled Comparison of Behavioural Arousal Levels in Urine Spraying and Latrining Cats. Animals10(1), 117.

Ramos, D., Reche-Junior, A., Fragoso, P. L., Palme, R., Yanasse, N. K., Gouvêa, V. R., ... & Mills, D. S. (2013). Are cats (Felis catus) from multi-cat households more stressed? Evidence from assessment of fecal glucocorticoid metabolite analysis. Physiology & behavior122, 72-75.

Schatz, S., & Palme, R. (2001). Measurement of faecal cortisol metabolites in cats and dogs: a non-invasive method for evaluating adrenocortical function. Veterinary research communications25(4), 271-287.

Being a cat behaviorist often means interesting conversations with strangers. People always have questions about their cats, but not always the questions I would like to answer, such as “how can I make my cat happy?” or “how many litter boxes does my cat need?” No – people want to know about idiosyncrasies such as, ”Does my cat hate my boyfriend?” or “Does the full moon make my cat crazy?”

For some reason, people are surprisingly concerned about being eaten by their pet after they die. A Google search for “will your pet eat you when you die” has over 400 MILLION hits. Perhaps you should be concerned because science suggests that the answer to that question is a resounding “Yes.”

A recent paper, “The scavenging patterns of feral cats on human remains in an outdoors setting,” published in the Journal of Forensic Sciences, perhaps needs a little context. To my knowledge, the researchers were not directly testing whether cats will eat human remains…but sometimes when you are doing science, the unexpected happens. And sometimes that unexpected is a scientific discovery in and of itself.

In this case, researchers at the Forensic Investigation Research Station (FIRS) in Colorado were doing what they normally do: studying the decomposition of human bodies. Now this alone is a topic of great fascination (at least if you are me), and I highly recommend reading Mary Roach’s book “Stiff” if you want to know more about what happens to bodies donated to science! It’s a truly fascinating read. ANYWAY, back to FIRS. They have an outdoor “decomposition facility” which is fenced to keep out large predators and is under surveillance to monitor the normal tissue damage caused by weather exposure and other happenings, including scavenging by small animals (typically birds, insects, and mice).

The paper reports that five days after a body was added to the outdoor facility, a “striped cat” breached security and was observed consuming said body, which belonged to a 79-year old woman. I hate to say it, but the demographic fits. The cat was consuming tissue from the left arm and chest. In order to complete the ongoing research project without interference by the tabby, a cage was placed around the body for a week, which put a temporary halt to the snacking. But when the cage was removed, the cat returned and continue scavenging the same body for the next month or so.

When a second, all-black cat showed up on the scene, the scientists allowed him to scavenge to his fuzzy heart’s delight. In this case, he chose a 70-year old man’s body who had been in the outdoor facility for almost a week. This cat also had a taste for the left side of the body, preferring the arm and abdomen. The cat made 12 visits over the course of about six weeks, always visiting the same body.

In both cases, the cats showed a preference for a particular body and particular locations on the body. Both cats had ready access to around 40 other people, and new bodies came and went, but each cat chose to chomp on the same body, repeatedly. The cats also showed a preference to scavenge where the tissue had previously been damaged, although the bodies were described as being in relatively early stages of decomposition.

Now lest you think I’m throwing cats under the bus for a sensationalistic news story, I’d like to bring up a few things. First of all, this finding is interesting not just because I’m fascinated by morbid things, but because cats are naturally hunters, not scavengers. Scavenging is something dogs do, and scavenging behavior is rarely observed in felid species. However, this publication opens up the possibility that scavenging is more common than thought in cats. Or that scavenging  might be influenced by other factors, such as hunger.

Second, before you go and hug your dog now that you’ve realized that your cat could eat you if you die – not so fast!! A Google Scholar search for “postmortem injuries pets” led to a deep dive into the world of forensic sciences where indoor pets do occasionally eat their deceased human. This deep dive revealed that perhaps your dog has evolved to love you, but he won’t think twice about eating your body after you die and he’s trapped with your body – EVEN IF HE’S NOT HUNGRY!! Dogs have been found shortly after a human’s death, with a full bowl of food and a stomach full of human flesh. Side note: there was even a golden hamster who indulged in some postmortem tasting of his respective human.

The 1994 publication in the American Journal of Forensic Medicine and Pathology, “Postmortem Injuries by Indoor Pets” identified a few key risks to being eaten by your pet after you die:

  • having free-moving pets in the home
  • being socially isolated (meaning discovery of your body is delayed), and
  • having an illness that might lead to sudden death.

Because some of these scavenging incidents happen shortly after the human dies, other researchers have theorized that it’s not necessarily hunger that triggers the injuries that occur, but an attempt by the pet to get the attention of or even revive their human. That said, a lot of injuries inflicted by pets after their human’s death do appear to be hunger motivated, and many of the pets who did eat their humans also died of starvation themselves (or in one case, from being poisoned from the drugs that their owner had overdosed on).

If push came to shove, would your cat eat you? Yes. But so would your dog. Our pets have no moral code that prevents them from eating flesh, from biting the hand that fed them. They have no need to uphold a standard that -- to many of us -- reflects a deep and loving relationship and a line that should not be crossed. The irony is that many of us have difficulty discerning why we eat some animals and love others. But to our pets, if we are dead, it may be that in that moment we are just meat.

Thank you to Julie Hecht for her helpful feedback on this post!

References:

Garcia, S., Smith, A., Baigent, C., & Connor, M. (2019). The Scavenging Patterns of Feral Cats on Human Remains in an Outdoor Setting. Journal of Forensic Sciences.

Herzog, H. (2010). Some we love, some we hate, some we eat. Harper Books.

Roach, M. (2003). Stiff: The Curious Lives of Human Cadavers. W.W. Norton & Company.

Rossi, M. L., Shahrom, A. W., Chapman, R. C., & Vanezis, P. (1994). Postmortem injuries by indoor pets. The American Journal of Forensic Medicine and Pathology15(2), 105-109.

Suntirukpong, A., Mann, R. W., & DeFreytas, J. R. (2017). Postmortem Scavenging of Human Remains by Domestic Cats. Siriraj Medical Journal69(6), 384-387.

If you’ve ever worked in a shelter or veterinary setting, there’s a pretty good chance that you’ve spent some time scruffing cats. Maybe you’ve taken your cat to the vet and the veterinary staff placed your cat in a “scruff-hold.” For those of you who have no idea what I’m talking about, scruffing is a way of restraining cats, by holding them firmly by the loose skin at the back of the neck. For some cats, this type of handling restricts their movement, which can facilitate handling and various procedures like getting a blood sample. Although scruffing is still a common way to handle cats in veterinary clinics, there is increasing resistance to using this type of handling.

Mother cat carrying kitten. Photo by Margo Akermark via Wikimedia Commons.

Scruffing likely came into fashion because it resembles the way that mother cats handle their kittens – carrying them by the back of their neck. When the momcat does this, kittens are immobilized and likely easier for mom to relocate. Immobility in other species (such as rabbits and rodents) when scruffed is attributed to anti-predator behavior. Scruffing adult cats can have similar effects (induced immobility), although not in all cats. Because the lack of movement experienced by cats during scruffing may be due to fear, rather than a relaxed state, many individuals and organizations are calling for veterinary staff to embrace other handling techniques for cats.

International Cat Care and the American Association of Feline Practitioners have released statements that scruffing should either not be performed, or should not be the routine, “default” method of handling cats who visit a vet clinic. Other organizations, such as the ASPCA, emphasize other methods of cat restraint. Various certifications are now available for training in low-stress handling, fear-free veterinary practice, and cat-friendly practices.

Now this is all well and good, but as can happen, sometimes people endorse a practice without a strong evidence base. Until the past few months, there have been few published studies related to cat restraint, and whether or not certain handling methods are truly stressful to cats. Dr. Carly Moody devoted her dissertation research to the exploration of various aspects of cat restraint. I blogged about two of her other studies recently, and now she’s got a new paper, hot off the presses, looking at three types of cat restraint.  In “Getting a grip: cats respond negatively to scruffing and clips” published in Veterinary Record, scruffing, clipping, and full-body restraint were compared with passive restraint to see whether they led to stress responses in cats.

Fifty-two shelter cats were tested; all cats experienced passive restraint as a control and ONE of the other forms of restraint. Some cats were held with passive restraint first, and others received the experimental condition first, to control for any order effects of being handled. Cats were first assessed as either friendly or unfriendly (I’d prefer a term like avoidant!) by measuring their approach and response to a stranger and being petted, before the restraint methods were tested.

Photo by Moody et al, from the published manuscript.

In passive restraint (a), cats were handled with minimal pressure and were allowed to stay in the position they preferred. Full-body restraint (b) involved holding the cat on its side, while holding the legs and not allowing much movement. In the scruff condition (c), cats were held by the skin at the back of the neck and was allowed only minimal movement. Finally, in the clip conditionm(d), two Clipnosis clips were applied to the back of the cat’s neck. Clipnosis clips resemble binder clips, and are a way to scruff “hands-free.” All cats were restrained by the same person in the animal shelter’s clinic facility.

The stress measures included ear movement, respiration rate, pupil dilation, lip licking and vocalizations. The results showed that cats undergoing full-body restraint had a higher respiration rate and more vocalizations. Full-body restraint and clips led to more pupil dilation, and all three tested restraint methods led to more ear movements when compared with passive restraint. To summarize, full-body restraint and clips were the most stressful, and scruffing also led to more stress responses when compared to passive restraint. Three indicators of stress (respiration rate, pupil dilation, and ear movements) were consistent with the previous work from this lab. Based on this study, the authors recommend that people do not use full-body or clip restraint, and that scruffing should not be a default method of handling cats.

A few potential weaknesses of the study include the fact that they did not do any medical procedures on the cats to see if there was any relationship between the type of restraint and cat’s behavior during an exam. The full-body restraint involved laying the cats on their side, which was different from the other three conditions, where the cat was typically upright. It is difficult to say whether it was the restraint or the body position that might have led to the stress response.

An example of scruffing plus full-body restraint.

Finally, MY personal experience, is that most handlers who scruff cats, simultaneously place them on their sides in some type of full-body restraint. So it is possible that some people will think that because scruffing was not as stressful as the other tested modes of restraint, that it’s perfectly fine to utilize this form of handling with nary a second thought. It would be great to include this type of handling (scruff + restraining the body) in a future study – it is possible that combining the two techniques is even more stressful than just using one alone.

Scruffing doesn’t prevent biting; many veterinarians have been bitten by cats in practice, and since most clinics (perhaps until recently) likely use scruffing to restrain cats, it is obviously therefore not a guarantee of safety. However, it is a habit that many may find hard to break, especially if they are used to and comfortable scruffing, and not as experienced or comfortable using other methods, such as towel-wrapping or chemical restraint (drugs). Many years ago, when I worked in an animal shelter and handling a lot of cats, I was doing a lot of scruffing! That was the norm. In my current work situation, I’m not routinely restraining cats anymore. But if I were back in that position, I’d be ready to try something different.

At the School of Veterinary Medicine at UC Davis, we teach a cat handling lab to first year students, and the mantra is “EBY – Even Better Yet” – what can we do better to handle animals safely, and in a manner that is likely to reduce stressful responses in the present and during future veterinary visits. These students have typically been trained to scruff cats by default. Sometimes they express resistance to trying something new; but hopefully with practice and increasing evidence that scruffing increases stress, they will get more comfortable with other, less-stressful techniques.

Kitty in a towel wrap. Photo by Kerri Lee Smith via Flickr/Creative Commons License https://www.flickr.com/photos/77654185@N07/26719456934

I was recently inspired when my friend Ellen Carozza, LVT told me that her veterinary practice has been “scruff-free” for almost 20 years. And she still has all of her fingers! She has been a strong advocate for providing cats with a safe and low-stress experience at the vet clinic, and has excellent videos of how the staff at her clinic handle “difficult” or “aggressive” cats, including several types of towel wraps. It’s hard to argue with 20 years of proof that it’s not necessary for effective treatment of cats (when we tell the first year vet students that there are scruff-free cat clinics, it blows their minds!). But think of it this way – if aversive restraint techniques were just not allowed or available to you – what would you do instead? And now it’s hard to argue with the mounting scientific evidence that when it comes to handling cats, “less is more.”

 

Reference

Moody, CM.Mason, GJ.Dewey, CE.Niel, L.
(2019) Getting a grip: cats respond negatively to scruffing and clips

What do cats love about their litter box? Well it might depend…as I’ve blogged about before, research as clearly demonstrated the importance of cleanliness, and we can use cats’ behaviors to help us better understand when they are having a good experience in their kitty commode. And when they aren’t having a good experience? That is when you are likely to find cat urine on your backpack, your bathmat, your bed, your tub, your fruit basket, your shoes, oh and all kinds of other very strange and interesting places.

A new study adds another piece to the puzzle, testing the effect of a litter attractant on the box behaviors of sixteen cats.

The study, The behavioural effects of innovative litter designed to attract cats, was a collaboration between the University of Guelph, Purdue, and the funders, the Kent Pet Group (more on them later). Previous studies have shown that cats prefer clay clumping litter compared to other types (pellets and pearls). Likely due to the sensitive nature of cats’ feet as well as their desire to dig and scratch in a substrate before and after eliminating, they prefer a very fine-grained litter.

 

However, some cat owners do not like clay litter, and are looking for something that might be more environmentally friendly, or less dusty than clay litter, which can often send them down to the pet store in search of alternatives. Sometimes those alternatives cause more problems than they solve (TIDY CAT BREEZE and FELINE PINE, I’m looking at you – your products should come with warning labels). But how do cats feel about alternative litters? And can they be made more attractive with an “attractant”? That’s what the current study sought to find out.

The cats were brought into the lab from an animal shelter for about a month - the duration of the study (and they were all adopted out into homes after the study). The cats were housed in groups of eight, and their room had perches, hiding spots, beds and toys. The cats received social visits during the study.

Picture by Frayne et al., via a Creative Commons License.

Each group of cats had access to eight litter boxes that were cleaned twice daily. At first, half of the boxes had clay litter and the other half had a plant-based litter, and the cats were gradually transitioned to 100% plant-based litter by mixing the two, increasing the amount of plant-based litter in the clay litter boxes each day.

After about a week of transitioning, the test began, which was to compare the cats’ use of plant-based (PB) litter with a PB litter that included an ”attractant” (PB+ATTRACT; although the nature of this attractant is not revealed). Half of the boxes had PB+ATTRACT in them and the other half just had plain old PB litter. Video cameras were installed so litter box behaviors (digging, covering, number of paws in the box, sniffing, and whether the cat actually peed or pooped) could be assessed over the next few weeks.

The key findings included that, NO SURPRISE!! Cats really went to town in the box right after it had been scooped. They also seemed to prefer the location of one box (#3) and used that one more than any other box, which may have impacted the results (this box contained the plain PB litter without attractant added). Also, none of the cats eliminated anywhere besides a litter box during the duration of the study.

Did the cats prefer the litter with the attractant? The only difference was that the cats urinated significantly more often in the PB+ATTRACT litter. There were more effects of the sex of the cat, such that males spent more time covering and sniffing their eliminations compared to the female cats in the study. This behavioral difference has been found in other studies and likely reflects some of the behaviors related to mating that are retained even in neutered cats.

As I’ve mentioned before, litter box use does not equal preference. This study would have been strengthened if they had compared the PB litter with a clay-based litter of similar texture. But I think that would have gone against the funding source’s interest. The Kent Group, who funded the study, is the maker of “World’s Best Cat Litter” – so I’m guessing that the unnamed products in this study are WBCL and their new formulation that includes an “attractant.” My own experience as a consultant is that plenty of cats will use this litter, but a fair amount will not, and when tested with other choices, cats do not tend to prefer it.  I appreciate that a company is willing to publish their findings, as many corporations keep their research under wraps.

Is this how your cats perceive their litter boxes?
Picture by Jeff Barton via a Creative Commons License

Behaviors were only recorded during daytime hours, which may have limited observations of some cats who may prefer to eliminate overnight. The researchers also could have rotated the positions of the litter boxes with PB and PB+ATTRACT litter to eliminate any influence of litter box location. Another issue with the way the study was set up is that all of the litter boxes were in the same general location, which is not recommended in a home environment. Cats may experience multiple litter boxes that are side by side as one “elimination area” rather than separate boxes, which may make the area less attractive (think of the difference to us between a public restroom with a bunch of stalls versus one that is private!). This litter box crowding may have made some cats uncomfortable when eliminating, especially if all cats were interested in using the boxes right after they had been cleaned. An alternative approach would have been to have multiple locations in the enclosure that had the two types of litter side by side.

The finding that cats preferred to urinate in PB+ATTRACT litter is important – urinating outside of the box is an issue that sends many cats to the shelter, or even to their death, so anything that increases a cat’s interest in the litter box is good to be aware of. However, my mantra for your own cat is to give them some choices (here's a quick guide), and let them tell you what they like…and SCOOP SCOOP SCOOP!!!!!!!

Reference:

Frayne, J., Murray, S. M., Croney, C., Flickinger, E., Edwards, M., & Shoveller, A. K. (2019). The Behavioural Effects of Innovative Litter Developed to Attract Cats. Animals9(9), 683.

Did you know that cats should see their veterinarian at least once a year? That’s right, even if they are indoors only and seem healthy, it’s good to have a check-up. A big reason that people do not take their cat in for regular care (aside from money) is the stress they perceive that their cat experiences. A survey found that 38% of cat owners reported that they get stressed out just thinking about taking their cat to the vet, and 58% say their cat hates going to the vet. I’ve previously written about how training your cat to love a carrier can make this whole process a LOT easier. But what about what happens AT the vet?

Passive versus full-body restraint. Image from Moody et al., 2019

Researchers at the Ontario Veterinary College have published two studies exploring how the way cats are handled at the vet might effect their behavior.  The premise of both studies was comparing responses to what the authors call “passive restraint” (defined as handling the cat lightly in a position of the cat’s choosing) and “full-body restraint” (holding the cat on their side, while grabbing the cat’s legs, preventing movement of the head, body and limbs).

 

 

Both studies included (I think the same) 51 healthy adult shelter cats. All cats were first categorized as either friendly or unfriendly according to an “Unfamiliar Person” test. Each cat was individually placed in a room in a carrier. The carrier door was opened and the cat was given two minutes to choose to exit the carrier, explore the room, and approach the experimenter (an unfamiliar person). If at the end of two minutes, the cat was still in the carrier, the experimenter removed the top of the carrier and left the room, and the cat was given another minute to explore. At that point, the experimenter approached and attempted to pet the cat. Friendly cats had to leave the carrier, approach the experimenter within about a foot and a half, and allow petting. Twenty-four cats were categorized as friendly, and 23 as unfriendly.

Next, all cats were given a two-minute “mock” physical exam using either passive or full-body restraint. The experimenters measured how long it took to restrain the cat, as well as the presence of ear movements, tail lashing, lip licking, respiratory rate, and amount of pupil dilation to assess stress responses to both types of handling. Two cats in each condition were not able to be examined due to aggressive behavior.

Lip licking can be a sign of stress. Photo via Public Domain Pictures.

Now for the results of the first study “Can you handle it? Validating negative responses to restraint in cats”: it took longer to get cats into full-body restraint than passive restraint. Full-body restraint also resulted in a higher respiratory rate and more lip licking. Cats who had been subjected to full-body restraint were quicker to jump off the examination table. The authors concluded that the full-body restraint increases the activation of a cat’s stress system, and the attempts to escape the exam table suggest that those cats found the experience more aversive than the cats in the passive restraint condition.

Image from Moody et al., 2019

Fast-forward to 2019. The second study that was just published earlier this year in Applied Animal Behaviour Science, titled “Testing two behavioural paradigms for measuring post-handling cat aversion behavior,” looked at whether cats found the handler threatening AFTER being placed in either full-body or passive restraint. After the two-minute exam, cats were given two tests to assess how they felt about the person who did the exam. For the first, cats had previously been trained to walk down a runway for treats. Only 38 of the shelter cats were able to be trained to complete this task. The cat was placed on the runway, with the handler at the other end, and the experimenters recorded whether the cat approached or moved away from the handler.

There were no differences in the time it took cats to approach the handler, regardless of whether they had been subjected to passive or full-body restraint. Because no differences were found, and because a sizeable number of cats could not be trained to use the walkway, it appears that this is not a good measure of aversion responses in cats.

The apparatus used to test location preference. From Moody et al., 2019.

But wait, there’s more! The researchers next tested whether cats would form negative associations with a LOCATION after full-body restraint compared to passive. This study included 45 shelter cats and 10 adult laboratory cats who were group housed. All cats were subjected to BOTH restraint methods for one full minute, but in two different, visually distinct compartments of an enclosure. After the cat had been restrained, they were allowed to choose which side of the compartment they wanted to stay in – the one they had been passively restrained in, or the one in which they received full-body restraint. All laboratory cats, and the “friendly” shelter cats spent more time in the passive compartment; the “unfriendly” shelter cats were equally torn between compartments, perhaps finding both types of handling aversive.

From these studies, we can conclude that overall, cats have fewer stress-responses to passive restraint. For some cats, particularly the friendly ones, those stress-responses carried over to preferring the location that they had received passive restraint in compared to full-body restraint. However, the cats subjected to full-body restraint were no more or less likely to approach the person who had restrained her compared to the passively restrained cats, so to answer my original question, it doesn’t appear that cats hold much of a grudge if any.

Cat handling is a hot topic for a lot of reasons, and the trend of “less is more” can be found in several movements to help make the veterinary experience better for cats (e.g., Cat Friendly Practice, Fear Free and Low-Stress Handling programs). I feel like I should mention that “scruffing” or the restraint of cats by holding the skin of their neck is NOT what was tested in this study. I bring this up because scruffing is a commonly used method of restraint that is considered outdated and a bit  controversial, and unfortunately I know of no research to condemn or condone its use. Two studies (here and here) did not find strong evidence for aversive responses to a handling technique called “clipnosis” or pinch-induced behavioral inhibition in cats, which is sort of similar to scruffing. Regardless, the consensus is that cats should never be LIFTED by their scruff.

And, when we teach cat handling at the veterinary school, the messages that we try to leave in the student’s minds are, “do you automatically default to heavy handed techniques, and if so – why?"  and “EBYs (Even Better Yets)” – what can we do better next time?

References

Moody, C. M., Picketts, V. A., Mason, G. J., Dewey, C. E., & Niel, L. (2018). Can you handle it? Validating negative responses to restraint in cats. Applied Animal Behaviour Science204, 94-100.

Moody, C. M., Mason, G. J., Dewey, C. E., Landsberg, G. M., & Niel, L. (2019). Testing two behavioural paradigms for measuring post-handling cat aversion behaviour. Applied Animal Behaviour Science210, 73-80.

Nuti, V., Cantile, C., Gazzano, A., Sighieri, C., & Mariti, C. (2016). Pinch-induced behavioural inhibition (clipthesia) as a restraint method for cats during veterinary examinations: preliminary results on cat susceptibility and welfare. Animal Welfare25(1), 115-123.

Pozza, M. E., Stella, J. L., Chappuis-Gagnon, A. C., Wagner, S. O., & Buffington, C. T. (2008). Pinch-induced behavioral inhibition (‘clipnosis’) in domestic cats. Journal of Feline Medicine and Surgery10(1), 82-87.

A recent study, “Stable individual differences in vocalisation and motor activity during acute stress in the domestic cat,” from the Universidad Nacional Autónoma de México in Mexico City looked at whether or not adult cats were consistent in how much they vocalized and moved around in a repeated stressful situation. The stressful situation in question was being placed in a cat carrier three times (with one week between each testing session) to see how consistent each cat’s behavior was.


Photo by Hiroshi Shimizu

The behaviors in question were primarily the number of meows, but also how much movement each cat showed. Why meowing and activity? “Isolation calls” are commonly used to look at stress responses because animals tend to vocalize a lot when they are socially isolated. For example, kittens in a previous study by the same team at UNAM would meow and wiggle around a lot when separated from their mothers. The studies showed that the amount of meowing and activity was consistent within individuals across experimental sessions. What that means is that kittens who were more vocal and active compared to other kittens at one week of age were are also more vocal and active compared to other kittens at two and three weeks of age. From this the authors concluded that the responses to stress (vocalizing and being active) were stable behavioral responses that might reflect personality.

So that was in kittens who were very small (under a month old)...so what about adult cats? The study included 40 adult shelter cats, between 8 months and 11 years old. All of the cats were healthy, and had cat beds, toys, litter boxes, food, and water - all that good stuff - in the shelter. The researchers brought each cat into an unfamiliar testing room and then they placed the cat inside a standard cat carrier. They left the cat alone in the room in the carrier for 2 minutes. After 2 minutes they took the cat out of the carrier and put them back into their standard shelter housing. All of the trials were video recorded.

So what happened? First of all, there was an effect of age, such that older cats meowed less than younger cats.  Further analyses revealed that during the first trial the cats were more active while being confined in the carrier, but as trials continued, the cats moved less. Perhaps they habituated to being in the carrier across the three sessions. Motor activity was not a stable measure because the cats were generally not very consistent in how active they were between weeks.

The number of vocalizations did not vary statistically between trials -- there was consistency within an individual cat as to how much they meowed on each trial compared to other cats. Cats who meowed more in the carrier in week one were more likely to more the second and third times they were in a carrier. This is very similar to what the same researchers found regarding kittens!

There was no relationship between meowing and activity. Motor activity and vocalization may reflect two different aspects of responding to stress;  perhaps vocalizing is more related to fear or the separation, and activity may be more related to how an animal responds to a stressful situation -- do they have a more active or passive style?  Are they trying to get out or of the carrier, are they frustrated or maybe they are more fearful and trying to lay low for safety reasons?

The researchers concluded that activity is maybe not the most consistent way to measure stress but vocalisation seems to be a potentially repeatable marker of stress in non-human animals. This finding is similar to what has been revealed in cows, pigs, horses, kittens and now adult cats! Vocalizations are also often linked to negative emotional states. The researchers propose  that measuring vocalization may be an efficient way to measure the emotional state of animals, keeping in mind that in cats both the presence and absence of vocalization can be related to high levels of stress...so context is probably very important!!

The researchers propose that in the future looking at vocalizations in relationship to other stress responses (e.g., heart rate variability, stress hormones) could help determine whether or not vocalization is a good measure of being stressed out. Because meowing was consistent across the trials, how talkative a cat is in different situations may be one aspect of “stable individual differences” -- aka “purrsonality.”

References

Urrutia, A., Martínez-Byer, S., Szenczi, P., Hudson, R., & Bánszegi, O. (2019). Stable individual differences in vocalisation and motor activity during acute stress in the domestic cat. Behavioural Processes.
Hudson, R., Chacha, J., Bánszegi, O., Szenczi, P., & Rödel, H. G. (2017). Highly stable individual differences in the emission of separation calls during early development in the domestic cat. Developmental Psychobiology, 59(3), 367-374.

We are lucky to be in a time where more people are studying cat behavior.  But what are some of the best methods we should use to understand cats better?  A new study looks at whether not placing a camera on a cat directly is a good way to determine what the heck they’re getting up to.  Sometimes it’s difficult to observe cats at all times, or they may change their behavior when people are around, so a catcam would be handy way to observe cats in a remote way. 

One of the cats in the study.

The study, titled The Use of Animal-Borne Cameras to Video-track the Behavior of Domestic Cats started by placing small cameras on 21 pet cats with outdoor access.  The cameras weighed around 32 g which is well within the recommended weight guidelines for placing objects on animals to track their behavior.  Cats who seemed bothered by wearing the camera (5 cats) were removed from the study, leading 16 cats remaining in the study.  These cameras were able to generate video footage from the cat’s point of view. 

In order to determine if what was seen on the cat camera was a good way to determine what the cat was actually up to, the researchers also simultaneously filmed the cats during a significant portion of the study, so they could directly compare what they observed with what the catcam observed.

The authors observed 36 different behaviors including sleeping, walking, jumping, eating, hunting, digging…  and these behaviors were based on a previous study that provided a very detailed ethogram (a detailed catalog of all observed behaviors ) of what felines do.

After the researchers had generated all of this video footage, it needed to be coded and validated.  They tried a few different methods of quantifying what they observed: one was to code everything -- we call this continuous observation.  Then they also went through and checked the video every 10 seconds and noted what the cat was doing.  This “instantaneous” sampling of behavior could be a big time saver if effective.  Coding hours of video is a very labor-intensive endeavor, even though it provides a very thorough picture of what is happening.  So by comparing that continuous observation with the instantaneous observation, the authors could determine whether or not you can use a shortcut.  Finally, the authors wanted to know the minimum amount of footage that was needed to accurately represent what the cats were getting up to.

The results suggested that many behaviors could be determined from the catcam generated footage alone.  These included vocalizations, scratching an object, grooming, eating, and jumping.  However, some specific behaviors were difficult to distinguish based on the camera footage, such that a general category of behavior could be determined, but the specific behavior was a bit more challenging to identify, such as resting vs. lying down, or walking vs. trotting.

Some behaviors, like scratching, could be easily distinguished from catcam footage. Picture courtesy of Artyangel/Pixelbay:
https://pixabay.com/photos/cat-animal-scratching-2576794/

The ability to use instantaneous sampling as an accurate representation of behavior was highly dependent on the type of behavior as well as its frequency.  Common behaviors that are very brief in duration such as vocalizations or jumping were often missed.  Behaviors such as lying down or walking were easier to get accurate representation using the instantaneous sampling because they are more common and also tend to be longer in duration.  The authors also recommended that individual cats be observed at least 40 times to get an accurate sense of how they spend their time, keeping in mind that their sessions were a minimum of 8 minutes of observation (but the average length of their sessions was over an hour).

This study provides us with important guidelines for how we study cats, in this case these were cats with outdoor access.  A lot of times we just look at research results, without really diving deep into the methods.  Another nice thing is that the authors provide a lot of cool video footage from the study, and if you’re interested in how people study cats I recommend that you take a look.  Unfortunately, it seems like taking shortcuts when it comes to observing cat behavior may come at a price.  But depending on your research question, there may be times where it’s equally effective.  Cameras that are worn by animals are just one of many cool new ways to use technology to better understand cat behavior!

Huck, M., & Watson, S. (2019). The use of animal-borne cameras to video-track the behaviour of domestic cats. Applied Animal Behaviour Science.


I am a big fan of new behavioral studies that can help cats, and I’m also a big fan of using clicker training with cats. So when I saw a new study, “Clicker training increases exploratory behavior and time spent at the front of the enclosure in shelter cats,” had been published, I was very excited to check it out.

Unfortunately, the paper is a good example of why we have to be careful about drawing conclusions from research and for those of us who do research, why we have to be careful about how we design studies.

Picture by Dilara Goksel Parry

There’s no doubt that shelters are a stressful environment for most cats. Being in a shelter usually means that cats have been removed from their familiar territory and all that is contains (smells, sounds, familiar humans and other animals). There are other animals present in distress, and cats may have to be handled for medical treatment, and may not have the ability to escape fear-provoking stimuli. Previous studies have shown that a hiding space, enrichment, and some types of handling can provide benefits for shelter cats.

The current study intended to determine if clicker training for shelter cats could improve their outcomes by increasing activity and exploratory behaviors, things that might help shelter cats get adopted more quickly. The study included twelve singly-housed cats in an animal shelter, who received 10 minutes of clicker training, 3 times a week for two weeks.

Cats were first trained to make a connection between the clicker sound and a food reinforcement (we call this “charging the clicker”). Next, the trainer made the clicker sound and offered food any time the cat made a movement toward them, essentially shaping the cat to approach the front of their enclosure in exchange for a treat.

The results appear impressive – by the end of two weeks, cats spent more time at the front of the cage, and more time exploring. The training had no effect on whether cats showed more “friendly” behaviors (as rated by the “Human Approach Test,” or HAT, which assesses how cats respond to strange humans – do they approach or sniff an offered hand, or withdraw or show signs of aggression?). This all sounds great!! So where did things go wrong?

The fatal flaw in this study is that there is no control group – meaning a group of cats who did not receive the clicker training but were also tested for improvements in activity, exploration, and friendly behaviors. As someone who spent many years working in an animal shelter, I can attest to the fact that most cats will improve with time in a shelter environment just because they adjust to their new environment. In fact, previous research has shown that cats’ stress levels in novel environments improves significantly in 14 days…the same time frame as that in the clicker training study.

Without a control group, it is NOT POSSIBLE to say that the clicker training contributed anything to the improvements in behavior observed in these cats. It’s a behavioral equivalent of a placebo effect – these cats may have improved significantly with or without clicker training.

Another concern with this study is that the researchers did not control for how long the cats had been in the shelter when the clicker training was started. The range of time the cats had been in the study at the start of clicker training ranged from 2 to 21 days. If you looked at the four cats who improved on HAT scores, they had an average length of stay of 14.5 days when training began, compared to the other eight cats who had been in the shelter an average of 6.25 days when training started, again supporting a strong effect for time in the shelter on the cats’ behavior.

I don’t really like blogging to tear apart a study – doing research is difficult, and when doing research there are often minor flaws or things that if we could go back in time, we would do differently, no doubt. But the flaw in this study as presented is so fatal, that I’m surprised it was published as is (even the title suggests experimental support for the hypothesis that clicker training effects shelter cat behavior).

The sad thing is that this flaw could have easily been fixed just by having a control group of cats who did not receive clicker training, and seeing whether and how much their behavior changed during the same two week period (ideally, matching those cats to the clicker trained cats on how long they had already been in the shelter). If the researchers had done this, we might be playing a whole different ballgame folks.

Because when you do science, you can’t just think about what might prove your idea or hypothesis (“clicker training will increase activity in two weeks”) – you have to think about what would DISPROVE your idea or hypothesis – what are the OTHER possible explanations (“cats will become more active in the shelter in two weeks without clicker training,” “cats will become more active in a shelter in two weeks if they are offered toys to play with” etc.). Especially when it has already been demonstrated that cats improve in a new environment in about two weeks ANYWAY, to not control for this factor is doing the field of cat behavior research a disservice.

There are some classic writings on how to think about these issues when doing science, first of all, John Platt’s “Strong Inference” and Richard Chamberlain’s 1965 paper “The Method of Multiple Working Hypotheses” are every bit as relevant today as they were when published over 50 years ago (and should be required reading for anyone who is “science-ing”). The overarching messages: design your studies to get clean results, consider alternative possible explanations, and try to control for them. This is why including placebos and blinding folks is the gold standard for testing new medical treatments.

Hopefully someone will take the initiative to test the effects of clicker training on cats with these messages in mind in the future, so we can know for sure whether clicker training offers additional benefits for shelter cats above and beyond the effects of just getting comfortable with more time in the shelter.

References

Chamberlin, T. C. (1965). The method of multiple working hypotheses. Science, 754-759.

Gourkow, N., & Phillips, C. J. (2015). Effect of interactions with humans on behaviour, mucosal immunity and upper respiratory disease of shelter cats rated as contented on arrival. Preventive Veterinary Medicine121(3-4), 288-296.

Grant, R. A., & Warrior, J. R. (2019). Clicker training increases exploratory behaviour and time spent at the front of the enclosure in shelter cats; Implications for welfare and adoption rates. Applied Animal Behaviour Science211, 77-83.

Kessler, M. R., & Turner, D. C. (1997). Stress and adaptation of cats (Felis silvestris catus) housed singly, in pairs and in groups in boarding catteries. Animal Welfare6(3), 243-254.

Platt, J. R. (1964). Strong inference. Science146(3642), 347-353.

Stella, J. L., Croney, C. C., & Buffington, C. T. (2017). Behavior and welfare of domestic cats housed in cages larger than US norm. Journal of Applied Animal Welfare Science20(3), 296-312.