There is no such thing as a poisonous tadpole... the only time when a frog or toad is truly dangerous, is during their adult life when the poisons on their skins develops as a defense mechanism. I know this because I was one one of those "Hippy" toad licker's from back in high~school... (90's)...lol.
I think if I survived it, a dog could too, good times and god's love.