Hello, can anyone advise? I worm my cavalier girls every three months with panacur tablets. One of my girls was mated four weeks ago, I don't know yet if she's pregnant but I am horrified to have found a couple of 4in round worms on the kitchen floor! I did worm her 1 week before mating but I have also heard that roundworm larvae can be 'woken up' by pregnancy hormones. Is this true?

Hi beverly, I don't know about that but you will be able to worm her from day 40 with panacur 10% liquid. The instructions are on the box.

Regards, Dawn R.

Yes that is true - the larvae can lay dormant causing no harm, but be "woken up" as you put it by hormones released during pregnancy.

This is how the worms life cycle works, and the dormant larva wake up and pass through the placenta to the new host (puppies).

Yes, it's true; pregnancy hormones stimulate roundworm larvae to hatch (at around day 42, according to the book I have in front of me) and cross the placenta to the foetal pups, so the pups are born already infected. The bitch will also shed larvae in both colostrum and true milk, so bitch and puppies all need worming at the same time.