To be fair, dogs (and certainly dragons) have levels of intelligence much closer to the level of a human than a squirrel.
I am not so sure about this, I'd have to do some reading before making a statement.
I'm basing my statement about squirrels ~entirely off of the fact that IRL we have domesticated dogs and googled statblocks says the 5e squirrels have Int=2 and Mastiffs have Int=3. On the other hand, I have seen videos about squirrels participating in obstacle courses to get food, so who knows really...
Dragons, unfortunately, are not real so we can't really do any research besides reading 5e lore & statblocks, almost all of which I've seen show that dragons have humanish or better levels of intelligence.
