Small animals shouldn't slow your caravan down!

[Goostave]

Is your feature request related to a problem? Please describe.
Here's the scenario: You send a man in cars to trade, then you get attracted by cute cats and dogs in the shop, you buy them and find out your way home will take at least 3 times longer then the time you came, because the caravan speed was AVERAGED by slow animals. This doesn't seem to be logic, cuz small sized animals can be put in your back seats!

Describe the solution you'd like
A possible solution to me is that, based on the SIZE of the animal, small ones can be considered as passenger (if there are more seats), or as put in a cage to carry (like cargo?), so not affecting the travel speed.
For larger animals, the current situation is fine. If something needs to be added, then maybe you could add some special type of vehicles that can hold big animals so they don't slow your caravan down.

Thanks for the great mod!