The Knights of Silversnow, Book 16 by Tony Abbott

Cats don't bark. They meow. Or at least they did before Eric used Droonian magic in the Upper World. When he cast a spell with the wand of Urik, everything got messed up - now weird stuff, like barking cats, are all over Eric and his friends hurry down the magic staircase only to find more trouble. Earthquakes have rocked Droon; and Galen's under a nasty spell. Time for some back-up The brave Knights of Silversnow could help, but they're in a deep sleep in the Ice Hills. The knights have the power to make things right again, but only if the wand of Urik has the power to wake them up.