They can cause loose stools if quite a lot is eaten and there's also the possibility of choking or the rawhide swelling up inside the digestive system and causing a blockage. However, the same or similar can be said about a lot of other chews such as pig and cow ears, bull pizzle etc. and the degree of danger will partly be down to whether or not your dog chews carefully and how much he's allowed to have.
My younger Cocker is a careful chewer and he has Farmfood rolled rawhides, but only under supervision, and I always bin the chew when it becomes small enough that he could potentially try to swallow it down in one go. Farmfood is the only brand I'll use because they're guaranteed cow hide and aren't bleached. Most rawhides come from China and who knows what animal they're from or how they've been processed.
Other things I buy include cow ears, rabbit ears and tripe sticks from Zooplus. I used to buy bull pizzle from there too but my younger dog isn't keen on them and the older one nearly choked on one.
I don't give them pig ears or paddywack because both of them end up with upset tummies.
