Tigga, our beautfiul retriever also ate slug pellets. I'll not forget that weekend for a long time.
Natural remedies:
Copper bands -either around pots or around specific plants. They'll work to a point, but not if they get covered over with soil.
GravelBeer - Bury a container of cheap beer and the slugs who are really attracted to the smell and will fall in an drown.
But the best and safest method is hand picking them up yourself.
I believe that slugs and snails have a good sense of "home", so throwing them over the garden fence won't actually help.
Rest in peace little seven month old one, always a pup over the bridge.