Anything is dangerous. Dogs are tough and can hunt in stuff that we would not want too. The only thing that is real bad is spear grass. found on the prairies up north and in Canada But, This does not stop Pros from training up there year after year. I trained on the grounds in Canada that had been used since the turn of the centry for summer training. I never have had a problem. I have heard of a couple dogs that did die from getting the stuff in their lungs and it got infected. Also one our nat. champ years past. one year had to have surgery to removea spear grass spur from a infected lung
All my training and hunting coarses are planted in millet, milo, sorgum, and other small seeds never a problem