We have used frontline plus on our 2 pedigree labradors for a few years now with no problems. We found it effective in emliminating fleas and ticks and very user friendly. Until this month when both our dogs reacted to the product and began convulsing within 4 hours of application. Unfortunately 1 died from poisoning and the other is left with neurological problems. Initially our vet said the frontline plus would not of caused this but after days of researching this product he agreed that indeed there was a high possibility that this frontline plus batch could of indeed been the cause, particularly...