The Fatdog has now done something like 48 Munros and 16 (I think) Corbetts. From discussions I've had with others there are only a relatively small number of Munros where a medium sized dog couldn't go (mainly Skye). Depends on the dog, its temperament, conditions, type of terrain. You just have to take a sensible approach. Eg we were on Devil's Ridge in the Mamores last year. Having had a discussion with another dog hillwalker before hand I knew there was only one point that would be a problem, and even that had a bypass. As it worked out my son had a problem with vertigo so we had to back up having gone half way across. That would have been the most "interesting" one we had tackled. On the other hand I had been advised by others not to tackle the ridge to the east of Devils' Ridge with the dog.
FD is hooked up for all ridges, near crags, and near summits...in fact anywhere where I can't predict the terrain or I think she might be distracted and it seems to work well. I have to say it probably works with Maisie becasue she is a very relaxed animal who more or less stays on the path and plods her way upwards.
Sharp scree is also something to avoid as is prolonged work in icy snow as you risk cut paws. Oh yes - deer fences - a real sod if you have a big dog.
It's a case of doing your homework before hand and you'll be amazed how many hills you have at your disposal.
To get you started most of the hills I have done are here...
http://fatdogwalking.wordpress.com/Good luck