I have, at an uncountable number of times, been told that you shouldn't feed dogs pork, lamb, poultry and fish. The reason is that the dog will eat the bones, and the bones will fragment (as opposed to bones from cattle) and that is dangerous.
This doesn't make sense for several reasons:
I don't believe a pack of wolves wouldn't eat a boar if they get a chance (yes, boars are dangerous, but an old or sick boar that can't defend itself). The same goes for birds, fish and lambs. It would be an evolutionary dead end if eating a board would kill a wolf. Similarly, street dogs aren't exactly picky with what they eat and if they find an injured bird on the ground or some chicken remains in a the trash, they'll eat it.
Besides, why would they swallow large fragments of bone? The throat is the bottleneck, not the stomach or intestines. Clearly, as everyone who feed their dog dry fodder can see, the dog chews the pieces into something that it can swallow. Dogs/animals aren't stupid and try to swallow things that will choke them.
Finally, I can eat chicken bones. Many humans chew on the cartilage at the end of the thigh bones of chicken and unintentionally swallows some bone fragments. The same goes for fish - e.g., sardines are regularly served "ungutted" and you just swallow them, without problems. Bone marrow is very energy rich and it would be weird if dogs couldn't take advantage of that.
