Aww, those poor pups. In my experience whenever I gave my dogs dewormer, they felt better almost immediately. I didn't use the same thing though, I gave it to my dogs once, then again in 1 week. I actually just looked up the Safeguard website and its says give it to your dogs 3 days in a row, not seven. I highly recommend you at least
call your vet. Talking to the guy at vet supply really doesn't qualify, unless he's actually gone through all the schooling it takes to become a licensed/practicing veterinarian. Teddy was right too, make sure they are drinking plenty of water.Here's the link to Safeguard, know what you're giving your dogs.....
http://www.safe-guard-for-dogs.com/dewormer.html