It goes without saying that parents need to keenly monitor what their children watch on TV. The TV programs they view need to be suitable, age appropriate and non harmful also goes without saying.
However, even among those age appropriate and seemingly harmless programs, there are several concepts that may be confusing to children, and which may send out the wrong message without us realizing it.
Many cartoons or animated movies perform the important function of educating children about certain values: for instance several movies have an anti-cruelty message; that one must not be cruel to animals. They tell children to love and understand animals which of course positive. 
Consider the example of the hugely successful film Stuart Little where the parents are looking to adopt a child but decide to adopt a rat instead; the understanding here being that you don’t discriminate against someone just because they are different.
Excellent so far! But then it becomes important to explain to children that it is not possible to have a rat as a brother.
The personification of animals and then assuming human roles has been part of the story telling tradition since time immemorial. And the recent 3-D feature from DreamWorks Animation How to Train your Dragon is a recent example of this tradition. Animals are cute, cuddly and affectionate; they are loyal and trustworthy is the message sent out.
However, the potential dangers of attempting to befriend a wild animal have to be pointed out to a child, lest they try to befriend something really unsuitable and even downright dangerous!
If the harmless show off of a lion is Madagascar, Alex somehow gives your child the impression that every zoo lion is loving and entertaining, that would be an erroneous impression indeed.
What some of these films and animated films do is send the message (perhaps unwittingly) of the limitless possibility of interspecies love.
If in the hugely loveable film Shrek, the donkey married a dragon and went on to produce hybrid fire spewing offspring in the sequel, it was a funny and delightful way of getting across a message of plurality. But, it is also perhaps required for it to be made clear to children that they cannot grow up and marry their favorite horse!
So by all means let your children watch what is appropriate and entertaining for them, just supervise their viewing and make sure that they are not forming any erroneous concepts about animals vis-a-vis their relationship with humans.
