Yes, not just mastiff or large breeds but even a spaniel can develop this habbit.
Its just a dogs way of trying to dominate, or thinking he knows better where to go as opposed to being led by its master. This is a behavior dogs must not have. Try practicing some obidience with him (with firm consistency), one might think it has nothing to do with pulling on leash, but it teaches him respect for u, and restores the belief of u being master / or alpha which ever way you'd think of it.
When my dog tries to pull on the leash she is very stubborn, and wants to go explore some crap, I don't budge 1 inch further, and verbally encourage her to come my way, the first time it took about 4 minutes she stood there looking at me.. finally she gave up and followed i rewarded her with some praise. Following this for about 6-7 days, she now dosen't pull on the leash until something distracts her like a passing stray dog, or the colony guard patroling with a big stick, her curosity is aroused but i don't allow her to go explore if she pulls on the leash.
the above is just about my experience with this problem, my dog is a 5 month old rottweiler (quite strong).. some people solve this behavior by rewarding the dog with treats for not pulling, but i didn't know how to manage that.
M waiting for other folks to share their opinions on this one :)