Their study showed the pet went off their food, was more fearful, sought out attention, played less and became less active. And in one in four cases, this behaviour persisted beyond six months after the other dog’s death.
While the ability to grieve has been suggested for a number of animal species most notably elephants, there has been little evidence to support this.
Now scientists at the University of Milan say man’s best friend could be more sensitive than people think.
Dr Federica Pirrone, an author of the study, said: “Dog owners reported several statistically significant changes in the surviving dog after the death of the companion dog, both in terms of activities and emotions.
“This is potentially a major welfare issue that has been overlooked, considering the relatively high number of dogs who live with at least a companion dog.”
A survey involving 426 Italian people whose pet pooch had died while they also owned at least one other dog was carried out by the researchers. Owners were asked if they had noticed any changes in their dog’s behaviour since the death of their companion.
In 86 per cent of cases owners noticed negative changes, the team found, with 67 per cent reporting they became more attention-seeking. More than half said their surviving dog played less, while 46 per cent said they became less active.
At the same time, 35 per cent of owners found their furry friend spent more time sleeping and was more fearful. In 32 per cent of cases they also found the pet ate less, and 30 per cent said they were whining more.
How long both dogs had lived together did not influence the surviving dogs’ behaviour. The findings were published in Scientific Reports.