Conceived and designed the experiments: CCB. Performed the experiments: CCB. Analyzed the data: CCB. Contributed reagents/materials/analysis tools: CCB. Wrote the paper: CCB.
The authors have declared that no competing interests exist.
Tail-chasing is widely celebrated as normal canine behaviour in cultural references. However, all previous scientific studies of tail-chasing or ‘spinning’ have comprised small clinical populations of dogs with neurological, compulsive or other pathological conditions; most were ultimately euthanased. Thus, there is great disparity between scientific and public information on tail-chasing. I gathered data on the first large (
Tail-chasing in dogs is widely celebrated in cultural references, such as its depiction in the cheerful, repetitive phrases of Chopin's Minute Waltz
Clinical texts, e.g.
Several breeds are prone to compulsive tail-chasing, including Bull Terriers
Despite the general renown of the behaviour and its potential severity in clinical cases, little is known about tail-chasing in home contexts or when no clinical causes have been diagnosed. Yet, a search for “dog chasing tail” on the most popular video-sharing website
The sidebar on the right also offers views links to related videos, showing a thumbnail of the video content, the video title, and the number of times the video has been viewed. The usernames are withheld here for privacy reasons, but on YouTube™ they are hyperlinked to the uploaders' homepages, which usually contain information about their age, sex, country, and their other videos.
Despite the increasing accessibility of broadband and video cameras/phones to a wide demographic, the dogs and humans on YouTube™ will not represent
To date, video-sharing websites, such as YouTube™, have been studied regarding their potential for disseminating information to the public, in contexts including tobacco use
My aims were to describe (i) canine breed/morphological and (ii) behavioural characteristics, and the (iii) animal welfare implications and (iv) broad environmental contexts, associated with tail-chasing; and also (v) to describe human responses to it on YouTube™. I made no clinical diagnoses from the videos, but could broadly infer certain animal welfare implications from visible injuries and characteristics commonly associated with perseverative abnormal behaviours, including both frequent performance and persistence in the face of distraction.
I identified tail-chasing videos using the search term “dog chasing tail” on YouTube, which returned 3340 hits in November 2009. The videos were continually but gradually shuffled by YouTube's confidential search algorithms. Between Nov 2009 and August 2010, I collected data from the first 400 videos of the returned hits, subject to the following exclusion criteria: only one video was used per ‘uploader’ (person who uploaded a video to their YouTube™ account); and very dark or pixelated videos, or those not showing a domestic dog tail-chasing or spinning were discarded; photographic collages, professional videos, and advertisements were excluded, and in video collages, only the first continuous shot was used. It is worth noting that in some cases, the uploader may neither have owned the dog, nor have taken the footage themselves.
The following details were recorded from the videos (further details in
Clip ID and URL
the reported sex, age and nationality of the uploader
dog breed, sex and age
dog tail morphology
relevant human and dog behaviour observed in the video (summarized in
environmental context (indoors or outdoors; television switched on, off or unknown)
relevant descriptive comments by the uploader and viewers (summarised in
Behavioural characteristic | Description | Proportion of videos showing the characteristic (excluding videos with missing values) | Significant associations (↑ = positive association; ↓ = negative association | Odds ratio +/− S.E.; DF; P-value |
Tail-chasing frequency as indicated by uploader comments* | ‘Habitual’ (e.g. daily, “all the time”, “a lot”, “spends hours” tail-chasing, the dog is “obsessed”);‘Periodic’ (e.g. “from time to time”, “regularly”, “[the dog] usually tail-chases when…”);or ‘Rare’ (e.g. “[the dog] rarely does this”, I “managed to catch” the dog tail-chasing) | Habitual: 26/86 (30.2%);Periodic: 49/86 (57.0%);Rare: 11/86 (12.8%) | ↑Difficult to distract | 8.06+/−2.50; 9; 0.049 |
“ | “ | “ | ↑ ‘Stupid’ in uploader comments | 6.52+/−2.33; 23; 0.037 |
Difficult to distract | The dog did not stop chasing for more than 5 s despite a potential distraction (e.g. the owner commanded the dog to do something other than tail-chase, a sudden noise, or the dog collided with something hard enough to impede its progress) | 76/198 (38.4%) | ↓Play | 0.16+/−1.70; 102; 0.001 |
“ | “ | “ | ↓Encouragement | 0.28+/−1.40; 102; 0.000 |
“ | “ | “ | ↑ ‘Funny’ in public comments | 6.82+/−2.09; 24; 0.016 |
“ | “ | “ | Also see Habitual tail-chasing frequency | - |
Vocalisations heard during or within 5 s of tail-chasing | Barking | 54/366 (14.8%) | ↓Television and computer use | 0.30+/−1.51; 201; 0.004 |
“ | “ | “ | ↑Tail wagging | 2.30+/−1.45; 201; 0.026 |
“ | Growling | 75/353 (21.2%) | ↑Hunter Group (Parker et al., 2007) | 2.66+/−1.63; 83; 0.050 |
“ | “ | “ | ↑Age (i.e. adults) | 2.30+/−1.40; 206; 0.013 |
“ | Whining | 4/354 (1.1%) | (too rare to test) | - |
Collision | Dog collided with an object during or up to 30 s after tail-chasing | 101/393 (25.7%) | ↓Play | 0.37+/−1.53; 262; 0.019 |
“ | “ | “ | ↑Laughter | 2.12+/−1.32; 230; 0.007 |
Play behaviour | Within 5 s of a chasing bout, the dog exhibits a play bow (characteristic posture with the forelegs extended on the ground), object play (manipulation of a toy or other available object), social play (with human or conspecific), or locomotor play (e.g., bounding, rolling) | 66/389 (17.0%) | ↑Tail wagging | 3.89+/−1.40; 259; 0.000 |
“ | “ | “ | ↓Age | 0.24+/−1.39; 259; 0.000 |
“ | “ | “ | ↑Outside | 3.26+/−1.63; 260; 0.016 |
“ | “ | “ | ↓Funny | 0.04+/−3.60; 68; 0.023 |
“ | “ | “ | Also see Difficult to distract, and Collisions | - |
Tail wagging | Dog rhythmically moves its tail laterally at least twice in each direction within 5 s of a chasing bout, rather than it remaining inanimate or moving irregularly | 135/393 (25.7%) | ↑Age | 2.77+/−1.36; 207; 0.001 |
“ | “ | “ | ↑Television and computer use | 2.15+/−1.33; 237; 0.008 |
“ | “ | “ | ↑Mastiff-terriers | 2.67+/−1.63; 84; 0.046 |
“ | “ | “ | Also see Play Behaviour and Barking | - |
Mouths tail | Dog is clearly seen to bite, lick or hold the tail or hindquarters/hind leg in its mouth for at least 1 s | 248/392 (63.3%) | ↑Laughter | 1.78+/−1.27; 235; 0.018 |
“ | “ | “ | ↑‘Stupid’ in uploader comments | 4.16+/−1.67; 154; 0.006 |
When videos had no sound-track or the soundtrack was replaced by music, missing values were recorded for data reliant on sound; similarly missing values were recorded for videos without relevant comments or where the behaviour could not be clearly seen. The proportion of tail-chasing videos (excluding those with missing values) showing each characteristic is displayed, along with any significant associations with relevant predictors, for which the odds ratios, degrees of freedom, and P-values are displayed. *This odds ratio was calculated from a model using ‘Habitual’ vs other frequencies as a binary variable.
Human response to tail-chasing ( |
Proportion of videos (excluding videos with missing values) | Examples or synonyms (where relevant) |
|
- | - |
Laughter | 199/362 (55.0%) | Female: 66.4%; male 18.6%; both sexes: 15.0% |
Verbal encouragement | 119/362 (32.9%) | “Get your tail!”, “Get it!” |
‘Growling’ at dog | 6/321 (1.9%) | |
Physical manipulation | 74/371 (19.9%) | Placing the tail in the mouth, pulling or pinching the tail, waving the tail near the dog's face, pushing the hindquarters |
Tail attachment | 14/371 (3.8%) | Attaching hair bands, dog toys or treats, a bottle, a section of plastic piping, or string to the tail |
Verbal praise | 12/362 (3.3%) | “Good dog”, “Good girl/boy”, and other variants |
Physical praise | 2/371 (0.6%) | Patting or stroking the dog, or feeding it a treat, after a chasing bout |
|
- | - |
‘Funny’ | 149/253 (58.9%) | “Funny”, “haha”, “lol” (laugh out loud), “hilarious”, “comedy”, “humour”, “XD” (a laughing emoticon), “lmao” (laugh my ass off) |
‘Crazy’ | 65/250 (26.0%) | “Crazy”, “mad” (but not “gets mad” or “mad at” as these indicate perceived anger), “insane”, “mental”, “maniac”, “nuts”, “psycho”, “nutcase” |
‘Cute’ | 47/250 (18.8%) | “Cute”, “cutie”, “sweet”, “aww”, “adorable” |
‘Stupid’ | 38/251 (15.1%) | “Stupid”, “retard/retarded”, “nerd”, “dumb”, “duh/doh”, “dumbass”, “dopey”, “idiot”, “moron” |
‘Silly’ | 28/250 (11.2%) | “Silly”, “Goofy” |
‘Fun’ | 19/250 (7.6%) | “Fun”, “amusing”, “entertainment” |
‘Play’ | 12/250 (4.8%) | “Play”, “playing”, “game”, “playful” |
‘Dizzy’ | 11/250 (4.4%) | “Dizzy” |
‘Weird’ | 10/250 (4.0%) | “Weird” |
‘Tricks’ | 8/249 (3.2%) | Tail-chasing is the dog's “party trick” |
‘Awesome’ | 8/250 (3.2%) | “Awesome”, “cool”, “amazing”, “wow” |
‘Bored’ | 5/250 (2.0%) | “Bored” |
‘Hyper’ | 4/250 (1.6%) | “Hyper”, “hyperactive”, “energetic” |
Other | N/A | Angry, classic, clever, confused, crack up, curious, dirty, enjoy, freak, frenzy, frustrated, inner battle, itchy, loser, nerd, nice, obsessed (x 2), possessed, serious problems, smart, spaz, tipsy, torture, wild, wrong, “I love that my dog actually chases her tail” |
Explanations given | N/A | [The dog…] “loves/likes to tail-chase” (x6), “hates his tail”, is “entertaining herself”, is “having fun”, is “either bored or has high cholesterol”, “enjoys the dizziness”, does it “out of dominance”, “puts on a little show”, “needs prozac”, “chases on command” (x2), is “still a puppy”, “hasn't figured [his tail] is connected to him”, is showing “typical dog behaviour”, is playing “his favourite game” |
|
- | - |
‘Funny’ | 64/138 (46.0%) | As for ‘Uploader description’, plus “hilarious” |
‘Cute’ | 58/138 (41.7%) | As for ‘Uploader description’ |
‘Awesome’ | 16/138 (11.5%) | As for ‘Uploader description’, plus “impressive” |
‘Stupid’ | 11/138 (7.9%) | As for ‘Uploader description’, plus “daft”, “not that smart” |
‘Crazy’ | 4/138 (3.6%) | As for ‘Uploader description’, plus “bonkers” |
Other | N/A | “Great” (x2), “excellent”, “nice” (x3), “priceless”, “entertaining”, “weird”, “gay”, “fun” (x2), “cruel”, “animal abuse”, “I wonder why they do that”, “My dog does/did that too” (x7), “My dog bites his tail to the point of bleeding”, “My dog spins/chases faster than yours” (x4), “Dog chasing tail never gets old”, “I want your dog”, “I've never seen a dog do that”, “I feel bad for him”, “repetitive behaviours need to be checked by a vet”, “I love it when dogs and cats do that” |
Explanations given | N/A | [The dog…] has “high cholesterol” (x2), has “canine compulsive disorder”, is in “pain/discomfort”, has “Schizophrenia”, needs “the doggie chiropractor”, is “happy”, needs “toys”, “doesn't know [the tail] is part of their body yet”, has an “itchy tail”, has “worms”, is “hyper”, is “bored”, is “showing off”, has “a flea stuck in his tail” |
The percentages of videos are arranged in order of magnitude for each general category. The words that were accepted as valid synonyms for comment categories were shown. These were accepted only if they were consistent within the context of the whole comment, e.g. a comment was not included in the counts for ‘funny’ if the comment actually stated that the video was ‘not funny’, even though the keyword was present in the comment.
I structurally defined all the behaviours scored according to an ethogram (
I compared tail-chasing videos against 400 breed-matched control (non-tail-chasing) videos, to investigate associations between tail-chasing and tail morphology, such as whether docked tails were more or less frequently seen in tail-chasing versus control videos. The control videos were also used to identify whether dogs were more frequently indoors, and whether a television, computer, radio or music was switched on when tail-chasing. Breed- and age-matching was important because these factors affect the likelihood that dogs are taken outdoors and that their tails are docked. My control search terms were “[dog breed name]”+“dog” or “puppy” as appropriate to match each tail-chasing video. The first control video not yet scored for that breed was used in each case. Exclusion criteria were as before, but additionally, videos were excluded if the tail could not be clearly seen; if the control video included tail-chasing or spinning; or if the video seemed to involve animal cruelty, for ethical reasons (e.g. dog fights). The ensuing control videos included diverse footage: for example, dogs playing, vocalising, performing ‘tricks’, eating, dreaming, exercising, exploring novel stimuli, or interacting with other dogs, other pets, or humans.
A subset of the variables described in
The order in which videos were re-watched was randomized. The other observer (OHB; see Acknowledgements) was an experienced observer of animal behaviour, and was blind to the hypotheses being tested. He received five practice videos for which he could see my original scores, and he was given a detailed description of the scoring criteria for each variable (
Intra- and inter-observer agreement was tested using Fleiss' Kappa statistics for binary variables, and Kendall's W for ordinal variables (Minitab 15). Thresholds for clinical acceptability were defined as Moderate (
Within the 400 tail-chasing videos, I tested associations between specific tail-chasing behaviours and their predictors (other behaviours, dog characteristics, and human responses) using generalized linear mixed models (glmmPQL and glmmML in R). I included breed as a random factor in every model to control for non-independence of similar dogs, and compared breed groups (defined according to both the UK Kennel Club and genetic groupings found by Parker et al.
I also used generalized linear mixed models, as before, to compare tail-chasing and control videos. In these analyses, tail morphology, the in- or outdoor location, and television/computer/radio activity were used as predictors.
I selected models using Akaike information criteria, and identified (and thus avoided) multicollinearity using inflated standard error terms. The α-level for statistical significance was set at P≤0.05 in this exploratory study
Of the 400 uploaders of the tail-chasing videos, 69.0% were from the USA, 13.8% from the UK, 5.8% from Canada, and 9.8% from 19 other countries. There was no significant sex bias in uploaders: 30% were female, 24% male and 46% undeclared (Binomial test of 119 females of the 215 declared:
The mean tail-chasing video length was 59.8+/−2.8 s. Each video had a mean of 863+/−197 viewings by May 2011 (maximum = 58,613), giving a cumulative viewing figure of 313,225 for the 400 videos included here.
Associations between dog behaviour characteristics and context (excluding dogs with objects attached to their tails) are shown in
Approximately 38% of dogs appeared difficult to distract, or ‘perseverative’ during tail-chasing. Perseverative dogs were more likely to tail-chase habitually and to collide with objects when tail-chasing, and they were less likely to show play behaviours than were other tail-chasing dogs (
Play behaviours (defined in
Problematic tail-chasing (as indicated by the percentage of all tail-chasing videos that appeared perseverative or habitual per breed group) was distributed widely across diverse Kennel Club breed groups (
Kennel Club Breed group | Total tail-chasing videos ( |
Perseveration | Tail-chasing frequency | |||||||
Distractible ( |
Perseverative ( |
Percentage perseverative | Breeds exhibiting perseveration | Rare ( |
Periodic ( |
Habitual ( |
Percentage habitual | Breeds exhibiting habitual tail-chasing | ||
Gundog | 56 | 22 | 8 | 26.7 | Goldendoodle, Golden Retriever, Labrador | 2 | 9 | 3 | 21.4 | Labrador, Springer Spaniel |
Hound | 21 | 9 | 3 | 25.0 | Beagle, Dachshund | 1 | 1 | 0 | 0.0 | N/A |
Pastoral | 28 | 5 | 0 | 0.0 | N/A | 1 | 5 | 1 | 14.3 | Shetland Sheepdog |
Terrier | 86 | 28 | 20 | 41.7 | American Staffordshire Bull Terrier, Jack Russell Terrier, Patterdale Terrier, Pitbull, Staffordshire Bull Terrier, Yorkshire Terrier | 3 | 7 | 6 | 37.5 | American Staffordshire Bull Terrier, Jack Russell Terrier, Patterdale Terrier, Pitbull Terrier, Staffordshire Bull Terrier |
Toy | 56 | 11 | 14 | 56.0 | Chihuahua, Havenese, Papillon, Pekingese, Pug | 3 | 10 | 2 | 13.3 | Chihuahua, Shih Tzu |
Utility | 29 | 10 | 3 | 23.1 | Lhasa Apso, Shih Tzu | 0 | 4 | 2 | 33.3 | Lhasa Apso |
Working dog | 24 | 7 | 5 | 41.7 | Bernese Mountain Dog, Boxer | 1 | 2 | 0 | 0.0 | N/A |
Crossbreeds | 100 | 30 | 23 | 43.4 | N/A | 0 | 11 | 12 | 52.2 | N/A |
Breeds are grouped according to the Kennel Club, which takes into account the breed history and general usage. They can also be grouped both genetically, as described by Parker et al. (2007), but those data are not shown here because not all recognised breeds have been genetically characterised according to that system to date. Representative breeds that showed perseverative or habitual tail-chasing are listed for each breed group; these were identified from uploader descriptions, or if no breed was stated, the breed was estimated from the appearance of the dog. Only those videos that included a potentially distracting event (
While 69.3% of tail-chasing videos were categorized as ‘Pets and Animals’, 18.8% were categorized as ‘Comedy’ and 6.3% as ‘Entertainment’.
Human responses to tail-chasing are shown in
Viewers were 6.8 times more likely to describe perseverative dogs as ‘Funny’ (defined in
In nine videos (2.3%), at least one comment offered clinical explanations for the behaviour or suggested that the dog should be checked by a veterinarian (three comments by uploaders, and seven videos had at least one such comment by viewers). However, none of the descriptions indicated that uploaders had posted their video on YouTube™ specifically to raise awareness of clinical aspects of tail-chasing.
Videos showing tail-chasing were approximately 6.5 times less likely to be outdoors than were breed- and age-matched control videos (8.8% of tail-chasing videos were outdoors versus 38.8% of controls; Odds +/− S.E = 0.15+/−1.25; DF = 317; P<0.001); and when indoors, tail-chasing videos were over three times more likely to show a television or computer switched on than were controls (32.1% of indoor tail-chasing videos showed one switched on versus 9.1% of controls; Odds +/− S.E. = 3.35+/−1.34; DF = 106;
Control and tail-chasing videos showed no significant differences in tail morphology, such as length, docking, or hair-type (initial analyses had suggested that tails were longer in tail-chasing than control videos
The results here reveal new clinically relevant information that has been difficult to discover previously. Approximately one third of the dogs with complete data tail-chased habitually or appeared perseverative, and were significantly more likely than other tail-chasers to be described as ‘Stupid’ or ‘Funny’, respectively. Comments suggesting clinical explanations for habitual, perseverative tail-chasing were only seen on 2.3% of videos, so it seems that public awareness must indeed be very low. Regardless of clinical signs, about one quarter (25.1%) of tail-chasing videos were classified as Comedy or Entertainment, laughter was recorded in over half (55%) of videos, and encouragement in 43%; and almost half of viewer comments described the videos as ‘funny’ or ‘cute’. The vast and ever growing numbers of viewings that these and similar videos receive on YouTube™ will likely reinforce these perceptions, normalising tail-chasing behaviour yet further
The findings therefore indicate a gulf between public perception and indicators of poor welfare in tail-chasing dogs. This implies that many pathological tail-chasers may go untreated, and the behaviour is widely assumed to be normal and amusing regardless of its persistence. These results are perhaps not surprising considering that some owners also incorrectly perceive the – arguably less ambiguous – separation-related behaviours in their dogs (barking, whining, howling, scratching the door, destructive behaviour and inappropriate elimination) to indicate neutral or even positive welfare
Results in
In 17% of videos play behaviours were interspersed with tail-chasing; playing was less likely in perseverative dogs, but more likely in puppies than adult dogs. This is consistent with tail-chasing sometimes forming part of play, especially in puppies
Encouragement of tail-chasing was recorded in 43% of videos, and laughter, which could also inadvertently be reinforcing for dogs, was heard in 55% of videos. The true prevalence of encouragement and laughter, will depend on how frequently people manipulate the dog for the film (e.g. attaching objects to the tail), play up to the camera, or deliberately remain quiet or offscreen during filming. Some encouragement seen on YouTube™ may have directly distressed the dogs: in almost 2% of videos, humans ‘growled’ at dogs, and almost 20% of people physically manipulated the tail (
Compared with breed- and age-matched controls, tail-chasing videos were approximately 6.5 times less likely to be outdoors, and – when indoors – televisions or computers (but not radios or music players) were more frequently switched on. The breed- and age-matching was intended to control for some breeds being kept indoors to a greater extent than others. However, the environmental differences could still be Type I errors (falsely significant) if, for example, tail-chasing were one of the few canine behaviours that people tend to record indoors while watching television, rather than it being performed more in that situation
Nevertheless, the observed environmental differences are consistent with tail-chasing being triggered by a lack of exercise, under-stimulation, and/or insufficient attention from humans
The usual treatment for compulsive tail-chasing is drug therapy combined with behavioural therapy, such as increased owner attention and walks; the drugs may treat the clinical signs but behavioural change addresses the cause of the problem. However, owner compliance with behavioural recommendations is often poor, e.g.
Tail morphology and docking showed no significant differences between tail-chasing and control videos. A previous small-scale study
In summary, YouTube™ has offered the first large, study population of dogs chasing their tails in non-clinical contexts. Approximately one third of the dogs showed signs of clinical relevance, but this was rarely recognised openly by uploaders or viewers; indeed, dogs showing problematic tail-chasing were more likely than other dogs to be described as ‘Stupid’ or ‘Funny’. In 43% of videos tail-chasing was actively encouraged, which could risk reinforcing the behaviour excessively, and in some cases it included rough handling or goading the dog. The study also reveals that diverse dog breeds chase their tails on YouTube™, and that this seems predominantly to occur indoors when televisions or computers are switched on.
Future research could record more detail about the clinical signs: for example, details of tail-mouthing behaviour could indicate tail or hindquarter discomfort, and persistently chasing in one direction could help diagnose compulsivity
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Many thanks to Dr Oliver H. Burman for watching and behaviour-scoring the videos to allow testing for inter-observer reliability. Thanks also to Drs Holger Volk, Oliver H. Burman, Alex A. S. Weir, Prof. Alan Wilson and the anonymous referees for their constructive comments on the manuscript. I would like to acknowledge Verity J. Browning, who carried out her Bioveterinary Sciences Final Honours project on part of this subject under my supervision at the Royal Veterinary College, which effectively acted as a pilot for this study. The RVC has approved this manuscript (ID number: P/VCS/000147/) for publication.