Gothmog vs. Sauron

[Galadriel55]

Originally Posted by Eönwë

It takes a great elven warrior to kill Gothmog, whereas Sauron could have been killed by a dog (however great he was).

I'm not sure that Huan would be able to kill Sauron. He just took his physical form away. Sauron is a Maia, so it's not that simple to "kill"him. I don't think he was ever killed; when the Ring was destroyed he was just weakened too much for hi to begin anew. Also, Huan was not exactly a plain dog - it says that in his barking you could hear Orome's horn. It's like a bit of ORoe is inside Huan, and Orome is more powerful than Sauron, being a Valar.