The 3 new ones are 1 1/2 years old, but have NEVER been wormed. Thought I should start with Wazine first, from what I've read, to prevent them from getting blocked up with dead parasites. My others are 6 months old. Should I change my plan?
Valbazen is safe to use the first time it kills the worms slowly so you won't have a over load and it kills all worms, I wouldn't bother with the Wazine.