
Wow in all my years of owning the dogs (over 25) have never seen round worms in my own dogs or puppies.
I have always used Panacur including worming bitches during last three weeks of pregnancy. It does of course attack larval stages not just mature worms.
Tend to only worm when a bitch is to be mated and then everyone gets done when pups leave, so probably twice a year.
I use a multiwormer to cover the tapeworms (though touch wood have had no flea issues (use a household spray) about once a year.