I have never played hunter before so I don't know exactly what spell you are trying to cast, but I guess you want your pet to cast Charge right?

/petattack charge,,, [target=targettarget] <-- Wrong, I'm not even sure that macro actually works.

/cast [target=targettarget] petattack charge,,, <-- Why did you add those ,,,?

/castsequence [target=targettarget] ,,,Charge <-- This will make you press the button 3 times before your pet actually casts Charge.