Arrived in my inbox from Dictionary.com:

Word of the Day for Sunday, May 22, 2011

slaver \SLAV-uhr; SLAY-vuhr\, intransitive verb:

1. To slobber; to drool.

noun:
1. Saliva drooling from the mouth.

The tiger was slavering. It was thirsty. Or maybe hungry.
-- Eliseo Alberto, Caracol Beach
Two ancient, lopsided wooden signs declared NO TRESPASSERS! and BEWARE OF GUARD DOGS! The latter featured a slavering Doberman frothing at the mouth.
-- Meera Syal, Anita and Me
Slaver is probably of Scandinavian origin, perhaps ultimately from Old Norse slafra.

Everyone i know says slobber or drool for this usage. Slaver means to deal in slaves. I don't doubt the etymology, but at least among the people i know in North America, i don't think any would use slaver in this sense.