Is cinnamon dangerous for dogs?

In excessive amounts, I have tried a little sprinkled on my dogs food, who is a diabetic, but the cinnamon did not help lower her BG, but it did not hurt the dog, I don't recommend using it unless you have a reason, if you do only a sprinkle.

I recently checked with my veterinarian after giving my dog cinnamon and he did not know of any problems and did not have any concerns.

my dog ate cinnamon toast crunch i dropped on the floor, and then he swelled up like a balloon. he threw up and pooped 4 times before he went to bed. he passed alot of gas, and today he is normal size. was it the cereal he ate that made him swell?

I don't know, but Cinnamon toast crunch is not good for any creatures, including humans.

Read the ingredients.