[blazey]

Wild animals are those that in general are only kept in national wildlife parks/safari parks, exotics are animals that are generally kept in zoo's/safaris too but with licenses (if possibly a danger to people or are possibly an endangered species) or without, you may be able to keep as a 'pet' in the loosest possible sense, domesticated are your typical 'pet shop' animal, such as hamsters, cats, dogs, some birds, rabbits etc.

The tiger shouldn't have been shot down dead, tigers are classed as an endangered species and it should have been incapacitated. San Francisco has a world famous zoo that surely could have provided tranquilizer guns to deal with the problem.

Its a tiger, not a pussy cat, and if an area has a zoo then its not a good enough excuse to say that its just not equipped with the necessary drugs and guns to incap it.
If someone keeps venomous snakes then they should be expected to keep the anti-venom on premises or it should at least be accessible locally just in case otherwise the animal shouldn't be allowed to be kept. Same goes for tranquilizers when there are animals like the tiger being kept in captivity.

As for animals being kept in cages, I believe its often necessary as some endangered animals, for example the great panda, need monitoring for sexual activity and behaviour patterns and to try and see why they aren't breeding and so on.

Also, zoo's help fund such projects, and without the money that they makes from visitors they wouldn't be able to do what they do.