People keep pets for various reasons. Some of them feel lonely and want to have a living being beside them. The others earn money raising popular breeds of cats and dogs. There are also special cases like having a dog to protect your house or to help the blind; picking up sick animals and taking care of them. But the majority enjoy pets just because they are real fun. It is great to have such an active and always ready to play friend. Besides it is an open secret that animals can cure people for many illnesses.
Dogs, cats, hamsters, rats, parrots, fish, guinea pigs are considered to make good pets and are still favourite ones, because they are rather easy to look after, quite cheap to keep, and they get attached to their masters indeed.
It has become fashionable to keep exotic animals as pets. But in my opinion it is not reasonable at all : they make bad pets. First, it is very dangerous for the owners themselves. Second, other people (their neighbours for instance) are not safe either. Third, you should think of animals too: I am not sure that they feel comfortable in our environment.
I have had a dog since I was 12. I found it in the yard and brought it home. I was absolutely happy because my parents allowed me to keep it. It is a simple mongrel ['mʌŋgr(ə)l] and we call it Jack. It is neither big nor small, coal black and incredibly funny and cute. When it was a puppy it used to be bouncy and noisy, but now it behaves like an adult: it is serious and calm.
It has always been my share of household chores to walk the dog, feed it, wash its paws, brush its fur and clear away its dirt. What I really enjoy is to teach it different tricks or just run and jump together. I believe that we are true friends.