Wednesday evening, I purchased a 3 pack of Gold Sargeants Flea & Tick for weight 9 lbs to 14 or 20 lbs. I have a male Bichon mix that weighs 21 lbs and his sister that weights 13 lbs. I administered to both exactly as was directed on the instructions. Within an hour, the female was flipping all over the floor, scratching and shrieking. The male was scratching and lethargic. All night the female screamed. (We bathed both of them before we went to bed that night.) The next morning the female was getting serious. We were instructed to bring both in to the vet and leave them. The vet bathed both of them and injected solution under the female’s skin. I picked them up Thursday evening at the vet. It was implied that this has happened repeatedly with the same product. When I got home both were going crazy with scratching/itching. The female still crying and shrieking. Friday morning both of them had extreme burns on their backs and the male was crying and shaking. Right now they have horrible burns on their backs that we are working with to relieve their discomfort.