micky wrote in
:

Maybe this isn't OT, since dogs live in homes? Why do dogs scrach
their side with their hind leg?

Is it only because of fleas or do they itch like people? Either
way, what do they do about scratching their back and belly etc?

Dogs scratch for the same reason people do: because they itch. Doesn't necessarily have
anything to do with fleas.

Dogs use their hind legs to scratch their sides and heads because they can't reach those
parts of their bodies with their front legs.

They scratch itches on their bellies and butts with their teeth, and on their backs by rolling over
and wiggling. Ever seen a person scratch his back on a doorpost? Same idea exactly.