Over the years has attitude towards animals changed???

Zoos, game reserves, circuses, horse racing, aquariums and marine parks are just a few of the industries that involve unnecessary cruelty to animals in the 21st century, but have the conditions of these industries improved over the years?
One of the first known event to use animals for human entertainment was the roman games in which animals are forced to fight each other to the death, this is criticised in our modern world, yet dogfighting, roosterfighting and bullfighting are all still present in the 21st century. Although both dogfighting and roosterfighting are illegal in this country, it does still occur in Britain. Dogfighting is not illegal all around the world, and on average 16,000 dogs are killed each year.
In the 19th and 20th century, animals were locked in small cages, for human entertainment in zoos or for personal collections for the upper classes; wild animals were sytolen form their natural habitat and placed in overly small cages which were designed more the safety of the public than the comfort of the animal. However is this still the case for zoos in the 21st century?
People would assume that conditions of zoos have improved, over time, yet animals are still locked in small enclosures that are inadequate for their requirements.
Some would argue, zoos help animals by breeding endangered species. Although they are breeding these endangered or vulnerable animals, they would be unable to survive in their natural environment. This is due to them being co-dependent on zookeepers for things such as food, and they are unable to fend for themselves and be independent.
Due to over hunting, destruction of habitat and the exotic pet trade, many species have been driven to near extinction, because of the negative impact humans have had on these animals. Therefore if not driven to near extinction by humans it would not be necessary for these animals to be kept in zoos for breeding.
Conditions in many zoos have been criticised as being inhumane and sometimes outright cruel in our 'modern world', with Humboldt penguins at Scarborough sea life centre being prescribed anti-depressants because they are so unhappy. This is most likely due the low living standards and sheer small size of their enclosures.
In 2003, San Diego Zoo and Tampa's Lowry park zoo imported 11 captured African Elephants from Swaziland. So even the biggest zoos steal form the wild, and this is occurring in the 21st century, where we are supposed to be helping endangered animals, not stealing them form their natural habitat.
However over the years there has been laws passed to try to help zoo animals such as the Animal Welfare Act which helps to protect the welfare of individual zoo animals, but this act is not always followed.
So, doesn't this prove that cruelty to animals in zoos and other industries that use animals have not improved much, in some cases you could argue its worse in the 21st century; with animal cruelty now being covered up so zoos such as San Diego don't receive bad publicity, but occasionally the cruelty that occurs in these zoos are leaked, showing us what zoos are really like.