“Severe repetitive behaviour may significantly impair canine health as well as the interaction between the dog and the owner. This is why identifying risk factors can benefit both dogs and their owners,” says Doctoral Researcher Sini Sulkama from the University of Helsinki.
Interlinked behavioural problems
Repetitive behaviour was associated with other behavioural problems: aggressiveness and ADHD-like behaviour. In dogs who expressed either one of the latter, repetitive behaviour was also more common. Similar connections have also been found in human studies. In humans, obsessive-compulsive disorder (OCD) often occurs in conjunction with ADHD, in addition to which aggressiveness is associated with both disorders.
“The observations point to at least partially overlapping neurobiological pathways and brain regions underlying the disorders,” says Professor Hannes Lohi from the University of Helsinki and the Folkhälsan Research Center.
Differences between breeds
The study found that repetitive behaviour is clearly more common in certain dog breeds, such as the German Shepherd, the Chinese Crested Dog and the Welsh Corgi Pembroke. What merits particular consideration in breed differences is the breed-specific difference between repetitive symptoms. For example, Border Collies and other herding dogs have a high predisposition to compulsive staring and snatching at ‘invisible’ flies, while the most typical repetitive behaviour in Staffordshire Bull Terriers is tail chasing.
“Certain behaviours have become increasingly prevalent in different breeds, since each breed has its own breed-specific traits and uses. The observed differences between breeds provide clear indications of hereditary predisposition to repetitive behaviour,” Lohi notes.
Factors that increase stress boost predisposition
“We found that repetitive behaviour was more common in male dogs as well as in sterilised or castrated dogs. In addition, repetitive symptoms were more common in young dogs, while they again became more prevalent in ageing dogs. In old dogs, however, repetitive symptoms may result from a progressive neurological syndrome known as canine cognitive dysfunction, or dog dementia,” Sulkama says.
As a new finding, a link between repetitive behaviour and the owner’s dog experience was discovered. Repetitive symptoms are more common in dogs whose owners have not previously owned a dog compared to the dogs of owners with previous experience with dogs. The researchers also found that the absence of other dogs, a limited amount of exercise and a larger family size increased the likelihood of repetitive behaviour.
“The causality is not yet clear, and further research is needed. However, stress is known to increase the likelihood of repetitive behaviour. Perhaps more experienced dog owners are better able to provide their dogs with a less stressful setting. Or maybe inexperienced owners just don’t notice repetitive behaviour early enough, making it easier for such behaviour to become permanent. These are factors that can increase the dog’s frustration and the amount of stress they experience in their surroundings, thus exposing them to repetitive symptoms,” Sulkama muses.
With the help of an extensive behavioural survey, the canine gene research group headed by Professor Hannes Lohi collected data on nearly 4,500 dogs with the aim of identifying environmental factors that affect canine repetitive behaviour and its potential links to other behavioural traits. Repetitive behaviour and its severity were investigated by asking what kind of repetitive symptoms the dog has and how often they occur.
Sulkama S, Salonen M, Mikkola S, Hakanen E, Puurunen J, Araujo C, Lohi H. Aggressiveness, ADHD-like behaviour, and environment influence compulsive behaviour in dogs. Sci Rep, 2022. Doi: 10.1038/s41598-022-07443-6 http://nature.com/articles/s41598-022-07443-6