D&Dtools1

Your breath weapon acts as a targeted dispel magic, possibly dispelling magical effects affecting creatures caught in its area.
The modification applies only to the breath produced as part of the casting.
For each creature or object that fails its saving throw against your breath weapon and that is the target of one or more spells, you make a dispel check against each ongoing spell currently in effect on the object or creature.
A dispel check is 1d20 + 1 per caster level (maximum +15) against a DC of 11 + the spell's caster level.
A creature's magic items are not affected, and creatures and objects that rolled successful saving throws against your breath weapon are likewise not affected.
If a creature that is the effect of an ongoing spell (such as a monster summoned by monster summoning), is in the area and fails its saving throw against your breath weapon, you can also make a dispel check to end the spell that conjured the creature (returning it whence it came).
For each ongoing area or effect spell centered within the area of your breath weapon, you make a dispel check to dispel the spell.
You may choose to automatically succeed on dispel checks against any spell that you have cast.