I'm pretty sure that they could be trained to do this...their sense of smell is astounding.

They probably could, but Idk if anyone wants to take the time to do this. Usually if someone is allergic to that stuff it's easier to just keep it away from them then to train a dog to do it. But nice idea though.

Dogs can be trained to detect food allergens and they are being trained to do so already! I do it! We have peanut detecting dogs working right now, protecting kids with LIFE THREATENING allergies. It takes about six months to complete the training of these dogs - they have to learn to detect peanuts, peanut oil, peanut dust, peanut butter, etc and in the tiniest amounts you can even imagine. In fact, if you ate a single peanut and then wiped your hand on your pant leg or even on the seat of your chair, our dogs will find it and alert! If you go to a restaurant and they use a pan that had peanut oil in it for a previous dish but hadn't been completely cleaned before using it for a "peanut-free" dish, our dogs, when examining the plate of food (and, yes, they do that too!), would find it and alert! Kids can't even go to parks and enjoy themselves because, holy cow, if a peanut butter sandwich had been on the table before them, contact with that peanut butter can kill some of these kids - it's a BIG DEAL! So, our dogs are trained to find stuff humans can't see, smell -- detect! They're incredible! If the dog eats the food, it's NOT doing his or her job! However, if the dog gets food on his nose or muzzle and then that part of the body touches the allergic person, it will, assuming their allergic to the CONTACT, cause a problem. That's why, after every search, the owners of these vested service dogs wipe their faces with disposable wipes! Like I said, it takes about six months to train... first how to detect the peanuts, then how to detect the small amount and then how to search without drooling (NOT easy!) or tasting! After that, these dogs have more obedience training and socialization so they can go ANYWHERE and behave! Most of our peanut dogs are Standard Poodles (the big ones) because a lot of people with the food allergies also can't handle pet dander - but they can handle poodles!! It was news to me that they are considered the second most intelligent breed of dog... If you really want more information, you can go to www.peanutdog.com!

Their breath usually makes me sick, anyway!

They can and are trained to do it. I've seen one in action actually checking out plates of food and the do not eat the food because they've been trained not to do it. It's really cool and the kid sure loves that dog!!

Dogs CAN be and are being trained to detect peanuts, tree nuts, and seeds! Check out peanutdog.com for more information. The dogs do NOT eat the food - they are trained to simply detect it and point out the contaminated item. The dogs are service dogs and protected by the ADA so they can go anywhere with you! Google peanut detecting dogs and you can find articles and even video (on abcnew.com) of these dogs. Next, the peanutdog.com folks may be training Gluten Dogs! I kid you not!