lets think about this way
first its just a gif
second, if the real starflight the nightwing in the book series were to hunt for a dog for food, he'll win here's why
first off, there is a group of humanoid beings in the series called "scavengers" who are smaller than the dragons. i say scavengers are hobbits (i mean, humans would have had some bows and arrows and some spears before they had swords and knives and daggers that are the only weapons scavengers use. this is why i think that scavengers are actually hobbits who stole a lot of stuff from the humans and traveled to phyria, the land where the book series takes place at than humans.) but lets give the scavengers the benefit of the doubt and say that they are human beings in the middle ages before gunpowder, and say that their height is 5'6" (66 inches) and that starflights height from claw to his shoulder is 138.6 inches ( 11'6.6") the average dog is 6.3 to 34 inches to shoulder, so yeah there much easier target than a scavenger. also, remember, we're talking middle ages, so you can't love a dog so much and give it some nuclear waist to make him big and red like Clifford (seriously, there was a thing on MAD about that called Cliffordfield or something like that)
second in the book series, a nightwing can blast an fire for all of his life if he really needed to, for his tribe has that abillity that they can blast fire for all of time. read that again. so, even with you being a part god part dog thing (if you can even say so) and you can somehow handle the heat and get stronger with it, sooner or later, you'll have to much power and die because of that. plus, from what i've seen, it does somewhat actually damage you. plus, he could kill a dog with out using fire, because he is a dragon. he could use his claws on the dog or whip his tail at it or eat the dog plain in whole. therefore, he would defeat a dog easily so please listen and hopefully agree with me you would have lost