Dogs Cats

Is it healthy to treat dogs and cats the same?

My son said tonight I messed my animals head up. They do not know if they are cats, dogs or people. That if they ever got outside on there own they would get hurt. ( Well duh, but i knew where he was going with his thoughts) They would not understand other cats would hurt them so on. And that mentally they had no clue what they were.
I have taught the dogs tricks and the cats tricks. It is really funny watching a cat roll on its back and pretend die.You just do not see that often.
They sleep together, clean eachother, sleep on top of the back of the couch when they want. (Dogs to)
And sit in the window watching birds.
I have two cats that have leashes for walks. They wanted to come so I took them.
So, do you think it is bad for them? Do you think they care?
I do not think they care if they are a dog, cat or human.
Really is there something some one can show me on a site that shows it is not good to treat them the same.

They have done studies that show human companions replace domestic animals mothers. They call them subsitute families (or stepfamilies, what ever works). So if this is a situation that you all are feeling happy in, be proud of your children and tell your son he needs to be nice to his brothers and sisters!