Owners can spend hours telling their dogs just how much they love them - all while knowing they'll never hear it back.
However, dogs have their own ways to show their owners their affection towards them - and it's usually so subtle their owners don't even pick up on it.
According to the Kennel Club, dogs are more likely to yawn when their owners do because yawning is contagious in humans and certain other animals.
Research shows humans who 'catch' a yawn from another person have better social skills than those who don't - with "contagious yawning believed to help show empathy with your fellow yawner".
Applying this to dogs, Dr Brian Hare, author of the book The Genius of Dogs and founder of the Duke Canine Cognition Centre at Duke University, said: "It’s reasonable to assume that dogs who yawn when their owners do are more emotionally connected to them.
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"They understand us in ways that other animals don’t, including great apes."
A study, undertaken at the University of Tokyo, found that just over half the dogs monitored yawned after watching their owners yawn.
The team also monitored dogs who watched a stranger yawn to see whether their results differed - and they discovered the dogs yawned about half as frequently.
Teresa Romero, an animal behaviour researcher who conducted the study, said: "Our results show the emotional bond between people and their dogs may be reciprocal."
A Kennel Club statement reads: "Romero says contagious yawning may be a way for animals who live together to coordinate activities.
"Since dogs and humans have been living together for between 14,000 and 30,000 years, contagious yawning may be deeply rooted in canine evolutionary history.
"Dogs’ longstanding relationships with us may have enabled them to reach across species lines to feel what we’re feeling."
Owners can test Dr Hare and Dr Romero's research by yawning in front of their dogs and watching their reaction to see whether they yawn back.
What's the best way to show your dog you love them?
Most dogs enjoy nothing more than spending time with their owners, but there's lots of ways you can make the day extra special.
Dr James Greenwood, resident vet on ITV's The Pet Show, said: "A daily walk is essential; dogs love using their senses to smell and explore and need to burn off calories exercising.
"I would also suggest setting up obstacle course or using puzzle feeders to get them thinking and problem solving."
"Food is also a big motivator for dogs and you can use this to your advantage when training by using treats as a reward for good behaviour.
"It’s also worth teaching our dogs how to be alone - gradual time spent on their own, with long lasting chews or toys to keep them occupied, is key to their development.
"Independence is necessary so they don’t become overly reliant on their pet parents or develop attachment issues."
Do you have a dog story to share? Email paige.freshwater@reachplc.com.
