Ugh. Let me share my experience with dog touring and reiterate what many others have shared.
My wife and I have a 40# dog who means the world to us. We take her on every vacation except those requiring flight. she loves hiking / backpacking / outdoors / etc. and can keep up with us for a week on the trail even though she's 10 years old. We thought we'd try bike touring.
She's just not into it. We trained and trained and trained. test rides, treats, bribes, etc, before going on tour. While on tour she freaked out and whined and tried to escape the trailer at every chance. We tried to take her on a long hike first thing in the morning to wear her out (and give her what she really wanted - a walk) but that didn't help anything and it just caused us to lose time on the road. it was miserable for all 3 of us.
Lots of people have great times with their dogs on tour. i'd highly recommend putting the time in with your dog now to get him/her acclimated. I could see it taking even up to an entire season of riding to accomplish this so don't start 4 weeks before your tour. and remain open to the idea that your dog just won't be into it.
also, old dog - new tricks.
this pic was from our one and only tour with Mari in 2011. We still have the trailer and our next dog will be indoctrinated at an early age. I think we're going to go so far as to set the trailer up in our living room (with the wheels off) to make her permanent bed. That way she will hopefully feel comfortable from the start.
EDIT: just realized this was in utility cycling subforum, not touring. I think the info is still relevant. Also, your dog is huge. No way on earth he/she will fit in Burley TailWaggin. Kids trailers are probably out too - they are just as small and the ones we looked at didn't have a flat supported bottom - just a sling for a kid to sit in. I didn't see a way we could reasonably modify to make our dog comfortable.