angie panacur kills roundworm and comes in granule (or liquid) form if you needed to do it more often.
Berties mum, this will work but wormers only kills whats there, they do not have any effect on what she might get next week. Also it would be perfectly safe for you to give her another in 2 weeks time (which i may be inclined to do then go to monthly worming)
Make sure you know the weight of minnie and that she is getting the right dose.