Henry was wormed every month until 6 months (just looked up in my old diary where I wrote these things down to remind me to give him the pills). The vet said it was only every 6 months after that but he did then get both tape and round worm at 9 months, so I will now be worming him every 3 months, since he eats everything. Ooh, just reminded me that I need to do the next one!