Dogs can eat sunflower seeds !
Sunflower seeds are a safe food to give to your dog on a couple conditions. The sunflower seeds should be peeled, and the seeds should be unsalted.
Sunflower seed shells are not meant to be digested, and because of this, they can cause your dog to have a stomach ache. If the sunflower seeds are salted, they become unhealthy for dogs, as salt is very unhealthy for them.
If you decide to give your dog some seeds, you should not give too many. If you give your dog to many seeds i can also cause stomach aches. Try to limit your dog to 10-20 seeds (small dog) and 20-40 seeds (large dog)