Cases of stress and depression in cats and dogs left home alone for long periods of time are increasing, research has suggested.
Dogs: Happier out and about than home alone
Eight out of 10 vets have seen pets with problems because they have been left while owners work and commute.
That is despite the majority of owners - 70% - saying they wanted their animal for companionship.
More than a quarter of pets are affected, the survey by More Than of 350 vets and 1,700 owners found.
Barking and yowling
Being left alone, a new baby in the family and the loss of a family member were the chief causes of stress and depression.
The findings come after Mintel research in June showed pets were being squeezed out of British households by lifestyle changes. Dog ownership fell by 26% between 1985 and 2004.
Veterinary advisor Sophie de Pelet said typical symptoms of stress in dogs included "destructive behaviour and excessive barking or yowling".
"More worryingly, persistent anxiety can contribute to long-term illness," she said.
Dogs ideally should not be left for longer than four or five hours. With cats, "if they are not getting companionship at home they may well uproot and move in elsewhere".
Lisa Marks, of BowWowMiaow, has been looking after people's pets full-time for six years.
She said stress in animals may have always existed but not been recognised - as with human stress. Diet, exercise, upbringing and environment play their part.
Snubbed cats 'may uproot' and go elsewhere
"For example - a border collie in a hectic family environment. You're asking a dog that's very intelligent and potentially highly strung to deal with children making high-pitched noises."
Obsessive behaviour like herding, nipping or self-mutilation can follow.
Her worst case was a dog who went to live with a full-time worker after its owner died. It chewed through the front door to find someone to keep it company.
"I'm not saying every dog needs a dog-walker, but they need human interaction. It's not huge hikes round parks - it's interaction."