Always used Frontline Plus. My vet switched to Frontline Gold.
Used it on both of my pure bred Labs. No issue on the 6 year old. My 16 month pup told me it hurt his skin when applied. About two days later, he was curled up in a ball, moaning, stumbled when walking, acting scared, no tail wagging.
After a half day, took him to emergency vet - inconclusive exam. I was told to monitor him and discuss with regular vet if symptoms do not go away. It has been 3 days now. Dog is beginning to get back to normal and I think all is going to be OK.
Bottom line - I have a very healthy, pampered Brit Lab who became very ill, mostly neurological plus physical ailment. I believe the only change to his situation was the Frontline Gold. I will NOT use this product again. I am a Chemical Engineer and do have some understanding of the chemistry behind this product.
Will need to find a replacement. Will go back to the old Frontline Plus and see how next month goes for him Will contact the manufacturer today and discuss also.
Product or Service Mentioned: Merial Frontline Gold Flea Control.
Reason of review: Bad quality.