OMGosh - that poor baby. MANY years ago I used Hartz on my cat too - and the same thing happened - foaming at the mouth etc...we were lucky because he wasn't poisoned by the toxins. Back then - we didn't have the net for information - and Flea Dips are very dangerous. Hartz has been killing cats and dogs for YEARS
Julz - I have a cocker too and I would just be insane with guilt if this happened to us - tell your sister to hang in there and hopefully this is temporary ? GOOD LUCK and I hope her baby will be ok......