Welcome to tankspot , It sounds like you did nothing wrong .If you get that toxin debuff and no one but the other tank has the fire debuff you where right to move towards the other tank .But what i remember is that dreadscale is kited but it does not need to be kited far or fast .So the other tank should be quite close to you so you would be able to get the fire buff from them quite easily. I find that whispering the tank before the encounter about the debuff the next time you go in , may help you alot . Also i would get the pvp enchant for your shoulders the 30stam 15res , From orgrimmar off the pvp vendor and maybe put 22 agility on your cloak. Also maybe get your enchanting up to enchant your rings too with the stam enchant. Which will rise your health up to .I hope this helps you and good luck with your tanking .
Hasslebelf armory http://eu.wowarmory.com/character-sh...&cn=Hasslebelf