Many dog owners suspect their pet is smarter than the average hound.
And soon they could be able to prove it - as researchers claim to have devised a reliable IQ test for canines.
British scientists have carried it out on border collies and found that dogs vary in how clever they are - just like humans.
They also discovered that animals which excelled at one task tended to do well in others, again following the pattern of how human intelligence works.
The research has a serious purpose, as it could help the team understand the link between intelligence and health problems such as dementia. Dr Rosalind Arden, from the London School of Economics, said: "In humans there is a small but measurable tendency for people who are brighter to be healthier and live longer.
"Dogs are one of the few animals that reproduce many features of dementia, so understanding their cognitive abilities could help us understand the causes in humans."
According to the findings published in Journal Intelligence, some 68 border collies from working backgrounds were given tasks such as finding hidden food - and showed a notable variation in their abilities. The researchers added that this is a "first step" in creating a "reliable, valid" IQ test for dogs.