Have you ever wondered which breed of dog barks the most, why black cats are a sign of good luck or which direction dogs wag their tail to show they are happy? Here are 36 fascinating facts from a new book on man’s two best friends…
Dogs can smell human fingerprints that are a week old. Their noses are so sensitive that they can even smell electricity. While conducting an experiment, a researcher found that a dog could smell which of two boxes contained an electric current.
He concluded this was because the charge resulted in the release of tiny amounts of ozone that the dog could detect. The source of the dog’s exceptional ability to smell is its wet snout.
The moist leathery surface acts like Velcro, catching even the tiniest molecules of smells, then dissolving them so that the dog’s internal smell-receptor cells can analyse them properly. To keep its nose wet, a dog must produce a constant supply of mucus through the nasal cavities. Scientists reckon the average dog produces a pint of this mucus every day.
Dogs prefer Bach to Britney. A study looked at the way hundreds of distressed rescue dogs reacted to different kinds of music. The sound of human voices and pop music by artists like Britney Spears did nothing to calm the stressed dogs. Heavy metal and grunge music made the dogs even more agitated. When the band Metallica were played, for instance, the dogs started barking loudly.
At the other end of the scale, however, the scientists discovered that dogs relaxed and enjoyed themselves most when they were played classical music. Naturally, they liked the sound of Bach in particular.
Male dogs tend to be left-pawed, while females favour their front right paw. Cats, on the other hand, are generally left-pawed. Studies found that 20 per cent of cats favoured their right paws when carrying out complicated, manipulatory tasks such as toying with objects, while a little over 38 per cent favoured their left. The remaining 42 per cent were ambidextrous.
Many owners think their cat senses their arrival home in the car: The truth is more likely to be that its ultrasonic hearing allows it to recognise the signature high-frequency sound of the owner’s car well in advance of its arrival within human earshot.
The ten brightest breeds of dog (ranked according to their ability to understand new commands in fewer than five repetitions and to obey first commands 95 per cent of the time or better) are: 1 Border Collie; 2 Poodle; 3 German Shepherd; 4 Golden Retriever; 5 Doberman Pinscher; 6 Shetland Sheepdog; 7 Labrador Retriever; 8 Papillon; 9 Rottweiler; 10 Australian Cattle Dog.
The ten least bright breeds (ranked in descending order of ability to understand new commands, even after hundreds of repetitions) are: 1 Basset Hound; 2 Mastiff; 3 Beagle; 4 Pekingese; 5 Bloodhound; 6 Borzoi; 7 Chow Chow; 8 Bulldog; 9 Basenji; 10 Afghan Hound.
Dogs have 42 teeth. Cats only have 30. The make-up of their mouths reflects their different dietary habits. At the front of the mouth, both have six incisors and two canines, used primarily for ripping. At the back of the mouth, however, dogs have more molars and premolars. These are used chiefly for crushing plants, roots, vegetables and bone, which cats don’t eat.
Happy dogs wag their tails predominantly to the right. A study of how dogs respond to different stimuli was conducted by Italian neuroscientists and vets. Over a month, they watched a group of 30 dogs respond when they were briefly joined in turn by their owner, an unfamiliar human, a cat or an unfamiliar dominant dog, a Belgian Shepherd. The dogs’ tails wagged vigorously to the right when they were shown their owners and much less so when they saw the unfamiliar human.
Cats lick themselves to protect against both the cold and excessive heat. In cold weather, licking helps to keep their fur smooth so that it functions as a more efficient layer of insulation. In hot weather, licking compensates for the cat’s lack of sweat glands and helps to cool down the fur. Historically, cats have been regarded as valuable weather forecasters.
Some dogs are more likely than others to demand affection. Highest-ranking breeds: Lhasa Apso, Boston Terrier, English Springer Spaniel, Cocker Spaniel, Toy Poodle, Miniature Poodle. Lowest-ranking breeds: Chow Chow, Akita, Bloodhound, Rottweiler, Basset Hound, Collie.
Hungry cats can meow at the rate of two per minute for more than two hours non-stop and can purr continuously for up to two hours. Adult cats convey different signals with a dozen different sounds. They signal territorial aggression by growling, howling and snarling, and defensiveness by spitting and hissing. The meow, trill and chirrup sounds signal greetings. Cats also gurgle. Scientists think this is a signal of friendship.
Cats and dogs are good for human health. The idea that pets may help prevent illness was raised in the 1980s when Erica Friedmann at the University of Maryland found that recovering heartattack patients tended to live longer if they had cats or dogs.
Female dogs have a lower boredom threshold than males. In a major study in which both sexes were encouraged to look at a selection of different humans, the females got bored more quickly than the males.
A dog’s barks last, on average, for 0.2 seconds each. A Beagle was once recorded barking 907 times in ten minutes. Some dogs are more likely than others to be guilty of excessive barking. Highest-ranking breeds: Yorkshire Terrier, Cairn Terrier, Miniature Schnauzer, West Highland White Terrier, Fox Terrier, Beagle.
Lowest-ranking breeds: Bloodhound, Golden Retriever, Akita, Rottweiler, Newfoundland.
Dogs are born with an equivalent of a thumb on the side of their feet. The extra digit, the dew claw, is a remnant of their evolutionary past that has become obsolete. The dew claw can be a handicap for working dogs in particular, as it can get caught in undergrowth and bushes.
Dogs can tell the time. During his famous experiments, the Russian physiologist Ivan Pavlov trained dogs to expect to receive food every half an hour. But when he changed the rules of the experiment and failed to give them anything, they still started salivating after almost exactly 30 minutes. Consciously or unconsciously, their internal clocks had told them to expect food.
The cat’s purr may be a self-healing mechanism. Cats purr at between 25 and 50 hertz, a frequency at which vibrations have been found to have a wide range of medical benefits, from increasing bone density and helping in the healing of fractures, torn tendons and muscles to generally relieving pain.
Cats are highly promiscuous. Male cats aren’t fussy about who they mate with.
Cats have more than 20 muscles in their external ears, or pinnae. As a result, they can move each ear independently of the other, using them to identify and amplify sounds quickly. They can also move their bodies in one direction while pointing their ears in another.
When researchers tracked the behaviour of a white tomcat for a year, they found he fathered 63 kittens with a number of different females. That’s one every six days or so.
Male cats appear to be possessive and certainly don’t like the idea of sharing. Indeed, knowing their partners are being “unfaithful” makes them less fertile. One study of the sexual activity of male cats found some were capable of having sex ten times in an hour.
An average mother cat has between one and eight kittens per litter, though a litter may contain as many as 13 kittens. In one case, a cat was discovered to be carrying 18 foetuses. One cat was recorded as having 420 kittens over a period of 17 years. The oldest known mother was pregnant at the age of 26.
Cats’ milk contains eight times more protein and three times as much fat as human milk.
Dogs have more taste-buds than cats. They have around 1,700 - almost four times as many as cats, which have approximately 470. A cat’s tastes are moulded when it is a kitten. During weaning its mother gives it a set of food preferences which remains in place for the rest of its life. From then on, a cat is extremely fussy about eating anything that it hasn’t tried before. So, despite the fact that raw meat is closer to the diet it would have in the wild, a domesticated cat raised on tinned cat food will shun uncooked cuts of meat that don’t look and smell like the processed product.
Cats are hypercarnivores. This means they need a much higher amount of protein in their diet than almost any other mammal. An adult cat needs its diet to contain 12 per cent protein while a kitten needs half as much again, 18 per cent. Dogs are capable of living healthily on much less than this. An adult dog needs a diet of only 4 per cent protein. This is why dogs are much better suited than cats to vegetarian diets.
Cats can fish. To land their catches, they use a cunning “flip” technique. Depending on the size of their prey, they will dip one or two front paws into the water and quickly slide them under the fish’s belly. They will then flip the fish out of the water, throwing it behind them, over their heads and on to land, where they will eat it. When kittens throw a ball up into the air as if to catch it, they are not playing. In fact, they are practising the fishing techniques they would use if they were living in the wild.
Chocolate can be poisonous to a dog because it contains high levels of theobromine, which is a cardiac stimulant and diuretic. Cats don’t like sweet things, mainly because they can’t taste them. By analysing the cat’s genetic code, scientists learned that part of the code that normally provides an animal with sweet-taste receptors is missing.
Cats are much less likely to become overweight than dogs. One vet reported that 30 per cent of dogs that came to his clinic were overweight. Only 10 per cent of cats suffered from obesity. Anorexia is more common in cats than dogs, though dogs can suffer from it. In their case, the condition is often associated with anxiety about being separated from their owners.
Contrary to the familiar saying, old dogs can learn new tricks - provided, that is, they are following a healthy lifestyle. A study discovered that when elderly Beagles were fed on a diet of fruit, vegetables and vitamins and exercised regularly, they were able to learn a whole range of new tasks. Scientists think the healthy regime and mental stimulation stave off the onset of Alzheimer’s and other brain-related illnesses common in older dogs.
The cat has a symmetrical walk, with its left limbs moving in sequence together, half a stride apart from its right limbs. The giraffe and the camel are thought to be among the few other animals that walk thisway. Cats normally walk at around 0.9 metres a second - that’s just over 2mph. Most breeds of domestic cat can run at speeds of up to 30mph. The Egyptian Mau, exceptionally fast, can reach up to 36mph.
Cats instinctively react to cold by baring their teeth and walking around in circles.
All 38 members of the modern cat family are believed to be descended from just eight ancestors: the ocelot, panther, caracal, baycat, Asian leopard, puma, lynx and the domestic cat. The domestic cat evolved from the African wild cat and six species of small cats that thrived around the Mediterranean.
Cats signal friendship by sticking their tails in the air. Scientists think this might be a rare case of a behaviour that has evolved since the domestic cat started living with humans. In the wild, cats raise their tails into an upright position only in order to spray urine. A household cat, however, adopts this position for long periods of time while it conducts friendly rubbing with another cat.
Black cats shouldn’t he seen as symbols of bad luck - quite the opposite, in fact. Scientists have discovered that, if anything, black cats have a fortunate genetic make-up. The gene for melanism, which makes their fur black, may also be able to prevent certain viruses or bacteria from entering their cells, making them more resistant to disease than cats with lighter-coloured coats. Dark coats also act as a better camouflage for hunting.
Among domestic breeds of cat, the Bengal has an unusual affinity for water. It frequently jumps into its owner’s bath, generally uninvited.
Cats have a blind spot, right under their nose. For this reason, they can’t find titbits on the floor.
Dogs are not colour-blind; they just don’t see the range of colours other species, such as humans, do. A study concluded their world is predominantly made up of yellows and blues. Cats can see limited amounts of colour.
Cats gets stuck up trees because of an evolutionary design fault. Their claws curve under, making them a useful tool for climbing up but less handy when coming down, as they can’t grip so effectively. As a result, cats tend to use a far-from-graceful backwards-sliding technique to get out of trees.
• Extracted from Play It Again, Tom by Augustus Brown, published by Bantam Press at £9.99, Augustus Brown. To order a copy (p&p free), call 0845 606 4206.
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