I think if they were real they would be like the animals we have now... but they could breath fire...
A Pigeon would be a Pidgey (But cuter and less fat)
A dog would be one of the dog Pokemon, depending on what county it is from.
Lapras would have to be some kind of new animal though, but they could live in the middle of the atlantic ocean, making them very rare!
If they were real I would have seen some rare pokemon though.
I once saw a Giant Dragonfly (It must have been 3/4 times bigger than a normal one) YANMEGA!
I have seen a wild gecko in Ibiza before (I would have caught it if it was a pokemon, I am from England so that would have been rare as hell!)
I might have had a Gastly too

One new years eve me, my brother and one of my cousins were out playing football, on the way home we walked past an abandoned pub. It had been abandoned for 2 years (the car park was still in use though) and the lights were just flickering on and off really fast, there was no car in the car park, so we didn't think anyone was there. We went to the window to investigate and found no one was inside. So it was either a ghost or a random power surge! I will never forget that though.