There has always been a dog at home. Sometimes two. I am one of the many who like dogs. People exist who don’t, but the rest of us think there’s something odd about them.

Along with dolphins and elephants, dogs are known to be smart. Some seem as sharp as razors, others, by comparison, a bit dim. But as a species (if that is what they are) dogs are extraordinarily clever: in just a few thousand years they have insinuated themselves into human life all over the world, thereby solving the life-and-death problems which were the daily curse of their wild ancestors.

In Egypt, where dogs are no longer regarded as companions or pets, you see bands of feral canines everywhere. What’s interesting is that they all look the same: light-brown with long noses and pointed ears. Since the Arab invasion, wild Egyptian hounds have undone all the careful breeding of 30 dynasties. They have regressed to become ‘average dog’.

My dogs have always named themselves. Poppy was a red setter who ate a poppy. Grass was a labrador who ate grass. Cracker, when young, managed to pull a Christmas cracker between her paws and fell down the stairs in panic.

Euan, my friend, likes bulldogs. He talks about the historical identification of bulldogs with the British character – we are called the ‘Bulldog Breed’, at least by ourselves – but, more than that, he is captivated by the bulldog’s placid temperament, which conceals immense strength. Once bulldogs have decided to do something (which takes quite a while) nothing on earth can deflect them. They are literally dogged.

I like sheep-dogs. Closer to their wild ancestors than other breeds, they are alert, fast, full of energy and intent on making themselves useful. When not running up and down hills, they stare at their owners as if to say: ‘Come on – give me something to do’. They will herd anything – cows, ducks, chickens, children.

Michael Rice, the egyptologist, owned two ‘Pharaoh Dogs’. They were identical twins. I first met them when I saw a pair of wooden statues either side of his office door and wondered how he had managed to find examples in such an excellent state of preservation. They were, indeed, as still and silent as the grave. Then one of them turned its head, and it took me several days to recover from the shock.

Dogs are supposed to resemble their owners, or vice-versa. A friend once owned an afghan, a breed known for being highly-strung, temperamental, capricious and slightly crazy. As she said, just like her. Euan could easily be a bulldog in human form. But I am not sure where this idea leaves owners of chihuahuas or poodles.

The entire global population of dogs has been identified genetically as stemming from a very few forebears. Just like us. Their founder families probably emerged at about the same time as ours, which gives dogs and people a unique shared history. It has always struck me as remarkable how much variety exists among the hundreds of breeds alive today; far more than in any other species. This is evidence, I suppose, of man’s ingenuity in ‘designing’ dogs for particular purposes. It doesn’t take long: a ‘new’ dog can be produced in ten generations.

Why are dogs such popular companions among bipeds? Perhaps because their species is so extremely socialised. This must be innate, but it has also been encouraged by human intervention and, presumably, by the dogs themselves – although a walk in the park tends to defy the notion of selectivity of any kind in dogs’ breeding preferences.

Loyalty has a lot to do with it. The quality which is so rare and highly-prized among people is taken as a given among dogs. ‘Friends in politics? If you want a friend, get a dog.’ There is something extremely heart-warming about an intelligent creature whose only desire is to be with you. You know that you are weak and faithless, your victories petty and your disappointments vast. But to your dog you are a hero.

I have a friend with two pyrenean mountain-dogs – huge, furry things with pink tongues and enormous tails which wag furiously whenever they see you. They have big, black noses and large, dark eyes. If you are watching TV they saunter up and lie down on your feet, which means you can’t move. I have often wondered who’s dominating whom.

As well as dogs, there have always been cats at home. Cats can be entertaining, but they’re no substitute. Self-absorbed, greedy, superior, wrapped up in their own egotistical fantasies, sometimes downright psychotic – they’re just like people. Give me dogs any day.