What bicycle trailer would you recomend for a large breed dog?
None of the dog specific ones are big enough, through researching on the net I think the burley cub would work - any ideas or experiences please? Would also like to be able to use it as a stroller and also maybe for kids in the future.

How heavy is your dog? Large breeds can weigh 200 lb
The weight limit for a Burley cub is 100lb (45kg)
http://www.bikesandtrailers.com/children/burley_cub.html#spec
If your dog is over 100 lb (45 kg)Try these guys their trailers are rated to 300 Lb (135 kg). A flat bed with a short fence should do the job.
http://www.bikesatwork.com/bike-trailers/
You will want to make sure your brakes are up to the task. A 2 into 1 lever running to brakes on both wheels of the trailer used instead of your normal rear brake should do the job.
http://www.trimuter.com/BL2-1-P13C4.aspx
Your dog will love riding it is even better than "the head out the window of the car". I’ve taken mine on a few charity rides. Everyone seems to get a bit of a kick out of it.
yes, I think you are on the right track. get the burley — they seem to me to be the best trailers. You may find good used ones on Craigslist.com. Most people are selling them after their kids out grow them, or buy one before test riding with the kids to see if they even like riding in a trailer.