That's interesting and I'm surprised. I can believe a lapdog but surely not a big dog, there are so many anti-dog squad out there these days I'd expct other passengers to complain.
Next question would be do you book so you are in 2 little seats together or book a table seat so he can sit under the table, but then he'd be in the way of other people... hmmmm..... (head scratcher....)
You are getting the wrong end of the stick, it wouldn't bother me I love dogs -How can you question Zacs that a lot of the population either don't like dogs or don't trust them? Look how many have won their desire to keep them off beaches and out of parks. My MIL would go berserk if she had to sit near a dog.