Never had a pet have a bad reaction except for one cat when I used a generic product. Just bathed him to remove the topical. He just lost some hair. All of my pets have used either Frontline or Advantage (dogs/cats) & have lived to be 11-16 years. Sorry for those that have lost pets. I know cancer have become an issue lately especially in goldens & I have 2 ( 1 & 13 yrs.) Studies are being done but will take some time for conclusion. I live in country & have fleas/ticks galore. Natural just doesn’t work for me.
