Originally posted by G.P.girl
it's ok for humans to be vegetarians because they were ment to eat plants and meat so they can live off only plants. but dogs and cats are only meannt to eat meat. so plants aren't very good for them,
Actually dogs are omnivores. Or primary carnivores (eats both, but more meat than other). Even cats need to eat vegetables and such. I hate to compare domesticated animals with their ancestors because of how much they have changed, but when you think about it, their ancestors all ate veggies too.

And like us some dogs can thrive on a vegan diet.
Yes, but people aren't "made" to eat the considerable amount of meat that a dog does. Some people eat only a small portion of meat every few days, and are healthy. But a dog's diet needs to have a large portion of meat everyday that is largest in proportion to what other parts the meal consists of.