Wikia

Lava Breath
Lava Breath 30 yd range 8 sec cooldown Instant Your pet breathes a double gout of molten lava at the target, reducing the target's casting speed by 50% (25% on player targets) for 10 sec.
Usable by
Class	Hunter
Pet	Core Hound
Properties
Type	Offensive, Utility
School	Fire
Cooldown	8 sec
Related debuff
Magic Lava Breath Casting speed slowed by 50%. Duration: 10 seconds

Lava Breath is a hunter pet ability unique to core hounds that slows the casting speed of enemies by a small amount of time.

Patch changes

Patch 3.0.9 (2009-02-10): Now reduces the target's casting speed by 25%, down from 50%.
/ Patch 3.0.2 (14-Oct-2008): Added.