How often should de-worming be done?
All puppies have worms when they’re tiny and generally deworming is done at least 3 times – usually at the same time as their puppy vaccinations are given.
After that, annual deworming should be enough, as long as your dog is kept parasite free.
You can learn more about worms in dogs on my Canine Worms page.
Hope this helps. Best of luck with your Rottie.