It is best to buy a kitten from a reputable breeder who is also a registered member of the Feline Control Council and registers their queens and studs with this body. They are very strict and will only register reputable kittens. The kittens are usually 12 or more weeks old when sold. They should have had two of their first three immunisations, be wormed and also toilet trained. For the first few days they may cry a little as they will be quite bewildered by the strange new surroundings, smells and the fact that their mother and other siblings are not with them.
Some breeders neuter their kittens before leaving for their new homes.
This saves the new owner the trouble at a later date, but it is made quite clear to the owner that the kitten MUST be neutered by 5 or 6 months unless it is being sold for breeding purposes. This up to the breeder to decide whether or not the kitten is suitable. They can become confused and frightened by thunder storms and lightning, then hide under someones house or in a shed and accidentally be locked in and you may not find your cat for days. These cats often start fights and could give your cat a nasty virus or bites and scratches which could become infected. The cat could then become very sick and may have to be put to sleep in extreme cases.