They're man's best friend - and rather cuddly and comforting too.
But researchers say you shouldn't hug your dog because it makes them sad.
As you close your arms around your pet, their animal reaction is to run away, meaning you are making them anxious by trapping them, researchers claim.
In a study of dogs, 81 per cent appeared to be stressed and uncomfortable when they were in a human's arms.
Dr Stanley Coren, a canine expert and professor of psychology at the University of British Columbia, in Canada, examined 250 pictures of dogs being hugged by adults and children, and analysed them for signs of stress.
When canines are especially anxious, they bare their teeth or bite, but Dr Coren said there are also subtler indicators.
Signs include flattened ears, half moon eyes, avoiding eye contact altogether or when a dog licks its lips. Yawning or raising one paw are other giveaways.
Only 7.6 per cent of the photographs Dr Coren studied showed comfortable dogs while the remaining 10.8 per cent were either neutral or ambiguous.
In an article in Psychology Today, Dr Coren wrote that "[there are] many pictures of happy people hugging what appear to be unhappy dogs", adding: "Dogs are not human children."
Dr Coren said: "The clear recommendation is to save your hugs for your two-footed family members and lovers. It is clearly better from the dog's point of view if you express your fondness for your pet with a pat, a kind word, and maybe a treat."