I've read that Hindus are mean to dogs because they believe bad people get reincarneted as dogs. Is this true?

I'm not so much concerned with the belief that bad people get reincarnated as dogs, as I am with the practice of being mean to dogs. I'm an animal lover especially a dog lover and Hinduism has always sounded like a cool religion to me (along with other "Eastern" religions), but it bothered me when I heard this about Hindus mistreating dogs. Thank you.