No Soy for Bulldogs?

So I seem to recall--and have found a few small mentions on some pages--that bulldogs must avoid soy products.

From the best I can discern, it appears that bulldogs are susceptible to soy allergies.

I was curious about this because several bulldog pages mention that they shouldn't eat kibble with soy; you shouldn't use soy oil to add to their food (use canola or corn). (See the Bulldog Club of America.)

But there's a chewing toy from Nylabone--the green ones I think?--that contain soy product in them. I don't know if this enough to warrant avoiding them.

Update: There seem to be stories about dogs dying from choking on Greenies... And bulldogs, specifically, choking on them and barfing them up in chunks. So definitely avoid those!