How to charm other animals?

This may not be the correct place to ask, so I am sorry in advance.

However, how does a ranger charm other pets? If you slot your charm skill, you have your cat. However, once you have the cat, your not able to charm another animal. Did I miss something? or are rangers not able to charm other animals?

there are tamers around that will take your tamed pet off you freeing you up to tame a new one.

can another ranger tame your pet? could you sell your lvl 20 pet to another ranger? that would be interesting, maybe a whole new ebay thing.