Dog breeders need to take action to improve canine mental health, scientists have said, after research found almost three-quarters of pet dogs have highly problematic anxiety-related behaviour.

While physical problems such as breathing difficulties and other health concerns relating to squashed-nosed breeds have become a hot topic, the study suggests breeders also need to focus on dogs’ behaviour.

“Behavioural problems are the leading cause for the relinquishment or euthanasia of the dogs,” said Prof Hannes Lohi, a co-author of the study from the University of Helsinki.

The study, published in the journal Scientific Reports, is based on a survey of owners of more than 13,700 pet dogs in Finland, spanning 264 breeds and ranging from young pups to elderly hounds.

It examined the frequency of seven anxiety-related traits, including noise sensitivity, fear, aggression, separation problems and compulsive behaviour, as well as sub-traits within these categories, such as tail-chasing. For each, dogs were classified as having low, medium or high levels of problems.

It found that 72.5% of dogs had highly problematic behaviour in at least one of the seven categories, and many had multiple problems. Almost a third of dogs showed high sensitivity to noise, with fireworks a particular problem, while 29% of dogs were said to be highly fearful and 14% showed highly problematic aggression.