Do our four-legged friends really see in black and white and what does it actually mean when they’re wagging their tails?
Dogs suffer from jealousy and are just as likely to turn into a green eyed monster as humans, according to scientists in California.
Researchers studied 36 dogs from 14 breeds and found that most were indifferent when their owners ignored them until the owners showered their attention on a stuffed dog.
Then the pet pooches’ behaviour changed dramatically, sparking snapping and snarling. The discovery shows that while dogs are man’s best friend, they still have the capacity to surprise us.
Here are some other facts you might not know about Fido.
1) Dogs don’t feel guilt
Your pet pooch may get jealous, but researchers found those puppy dog eyes are not a sign of guilt. In fact they are just the way we interpret a dog’s reaction to being scolded.
Alexandra Horowitz, from Barnard College in New York found all dogs looked ‘guilty’ after being told off for eating a forbidden treat like a biscuit – and those who were wrongly accused often looked more ‘guilty’ than those who really deserved to be in the dog house.
Maybe Denver didn’t eat the kitty treats after all…
2) Dog urine can corrode metal
Apparently allowing your dog to wee on a lamp-post could be more dangerous than you think – because the acids in the urine can corrode the metal.
In April 2003 Derbyshire County Council spent £75,000 carrying out a six month survey of one million lamp-posts amid fears that dog wee was causing the bases to crumple. In the same year, urinating dogs were blamed for a spate of lamp-posts collapsing in Croatia.
We dread to think what damage this mutt did to this Banksy mural in New York then.
3) Dogs can see in colour
It is a common myth that dogs can only see in black and white but they can actually see colours – just not as vividly as humans.
They only have two cones in their eyes to detect colours, whereas humans have three. That means dogs see colours on a blue and yellow scale but cannot distinguish between red and green. On the other hand, they have better night vision than humans.
4) Dogs can smell disease
If your canine chum is acting strange there might be nothing wrong with them – the problem could be with you.
Research at the Schillerhohe Hospital in Germany found dogs have an incredible ability to recognise the smell of a range of organic compounds that show the human body isn’t working as it should.
That means your dog can actually diagnose your cancer, something scientists are eager to explore further, as well as diabetes and the early signs of an epileptic seizure.
5) Dogs can be pretty smart
You might sometimes think your dog is as daft as a brush, but the truth is that they can actually be as smart as a two year-old child, according to research presented to the American Psychological Association.
Perhaps unsurprisingly, border collies are the cleverest canines, with some able to understand up to 200 words. The other breeds in the top five are poodles, German shepherds, golden retrievers and dobermans.
Don’t believe us? Just look at what Nana can do…
6) A wagging tail doesn’t always mean they are happy
Tail wagging has its own language. Apparently dogs wag their tail to the right when they’re happy and to the left when they are frightened. Wagging low means they are insecure and rapid movements accompanied by tense muscles or dilated pupils can signal agression.
So every wagging tail tells its own story, if you know how to read the signs.
7) They really are hot dogs
Next time you see your pet pooch panting on a sunny day take pity on them. Not only are they wearing a huge fur coat, they also have to contend with a higher body temperature than you.
The normal body temperature of a human is 37C, but a dog’s is a whole degree higher at 38C. That’s one reason fleas are more likely to be attracted to your dog than to you. And unlike humans, dogs don’t have sweat glands all over their body, just on the pads of their paws.
8) Dogs have their own ‘fingerprint’
A dog’s paw print may look pretty generic but their nose print is actually as unique as a human fingerprint. Their combination of ridges and creases is so distinct it can actually be used to identify them.
Good luck getting them to stick their nose in a pad of ink without sneezing though.
9) Dogs dream just like you
This won’t come as a huge surprise to anyone who has watched their own dog twitching or whimpering in their sleep. Dogs have the same brain wave patterns while they are asleep as humans, so they dream just like we do.
But what is more surprising is the fact that not all dogs dream the same amount. Small dogs actually have more dreams than big dogs. For example, a small dog such as a toy poodle may dream once every 10 minutes, whereas a great dane may have around an hour between each dream.
10) Dogs can fall in love
They don’t call it puppy love for nothing. The concept that dogs can fall in love was suggested by anthropologist Elizabeth Marshall Thomas, author of The Social Lives of Dogs, who believed two dogs named Sundog and Bean were agonized star-crossed lovers kept apart because neither of their owners wanted to give them up.
It may sound far fetched but Paul Zak, a professor at Claremont Graduate University in California, found that a dog’s brain releases oxytocin – the love hormone – when it interacts with humans and dogs, just the same as a human brain does when we hug or kiss.
11) When did we become friends?
Scientists believe that humans and dogs first became best friends 30,000 years ago and our close bond started in Ice Age Europe when wolves, ancestors of today’s domesticated dogs, were first tamed by the ancient hunter gatherers.