Daughter has 2 Jack Russell X pups who are 9 weeks old and her little darlings. She popped to the shop and brought back Bob Martin Spot on for small dogs and puppies to make sure no unwanted guests. I have never seen a reaction like it ,frothing at the mouth ,throwing themselves on the floor ,I quickly helped her to wash the stuff off with baby shampoo,but one of them became quite lethargic and we rang the vet ,who had heard of this happening before and said if he didnt perk up ,had sickness or runny poos etc, get him to surgery immeadiately. I normally use Frontline and have never had anything like this ,and what amazes me is that this stuff is sold on the supermarket shelves!! Has anyone else had the same thing??