I should add that while it's been a long time, I pulled kids in kiddie trailers back in the day, and it works reasonably well.
one thing not too forget is the additional weight of dog food and water.
I guess if a used kiddie trailer could be bought, you could at least see how it goes. Kiddie trailers can always be resold too, but I'm sure there are weight limits on them to be aware of.
I imagine too w even borrowing a trailer and putting in some weight like sacks of potatoes or whatever could quickly give you any idea of what you'd be up against.
anyway, all the best with whatever happens or doesn't.
One thing I've learned since retiring and having extra time to do things is that our brains relish the new adventures
but they're not necessarily in sync with our aging bodies. Up until I had cancer issues I was in excellent shape,
especially my legs, and believe that had I not had the issues they still would be in great shape to tackle riding with
the equivalent of another person's weight. During all my tours, I always used gearing rather then push too hard.
I relate it to the commercial trucks I drove with very heavy loads...having proper gears and using them gets the job
done without undue stress on the motor or drive train. One situation I think I would have problems with is when stopping
on a steep hill with all that weight. Trying to hold everything stopped and in control while attempting to get off or on
would be challenging, even potentially hurtful, and very likely turn the air around me blue, lol! It's sometimes hard to do
with just a normal loaded touring bike. Nope, it's best I go find someone to care for the dog, thanks.