Need help vs lock healer teams

Ok so we play Feral Druid and Frost Mage combo and we win vs almost all teams except pally/priest and a warlock we tried to sheep the healer and nuke the warlock but u cant keep on the healer all the time so he heald the lock from time to time and we get outdmgd and finaly die we tried to do it like vs war/pally sheep the lock kill the healer but fear gets in our way all the time right before an interuption and again we die.So is there any special tactic vs lock healer teams? or we just imposible combo to beat with our setup.

I would go for the pet to prevent interrupts & dispells, this will allow both of you to drink, use hots and your mage to keep shields on.

I know it can be a pain for a mage to do dmg to a fel puppy, but if he has trouble with that you can just make him CC the other two, just prevent them from casting while you kill the pet. Also he can put a few shatter combos on the lock, it will result in the lock playing defensively & also dmg his pet. A fire blast or A cone of cold will help bring down the pet aswell.

Spellstealing Fel domination could screw the lock up very bad & getting a fel armor with SS, your mage will benefit alot from your heals (if the lock forgets to recast it they will be in an even worse position)

Against preist teams just keep the pressure on the lock so the priest has to heal & doesn't have time to MB or dispel much.

I don't play this combo tho so i'm a bit guessing atm. IMHO you have little to no chance to defeat them with the pet active.