Vegetarians are fond of equating animals with people and saying that it's wrong to cause animals distress and /or shorten their lives unnaturally. However, it seems to me that if you follow line of reasoning, keeping pets and creating zoos is also very wrong. The one is a form of slavery, then, and the other a form of kidnapping.
I believe that if you are a vegetarian and don't agree that it's wrong to keep pets or create zoos, you're being hypocritical.
You can say that most pets are happy to be pets and have even been bred for that purpose, but vegetarians often argue that "Well, but we are more evolved creatures and have an obligation to lesser creatures whether they ask for our help or not."
Okay vegetarians, it's your turn to reply, Do you agree that keeping pets and establishing zoos is also immoral if eating animal matter is immoral, or do you have any arguments to escape from this conclusion. I would hope none of you have dogs, cats, or parrots (especially parrots, since they are far smarter than dogs and cats).
If captivity shortens the lives of animals .. how is it then they actually live longer in captivity overall? Last I checked animals in the wild didn't see vets or take medication when they were sick.
Also, at this point in domestication most house pets are entirely dependent on humans and would not be able to survive on their own . As a result, we'd be doing them a disservice by letting them go free.