I applied hartz to my cat and within minutes he was drooling all over himself and acting as if it was physically painful. I immediately washed it off with soap and water but Caillou continued to get worse. Within an hr he started having seizures so I rushed him to the vet where he was put on IV fluids and sedative to stop the seizure activity but to no avail. Caillou passed away early the next morning. Our family suffered to loss of a very special cat all because we were tryinging to make him more comfortable by treating his fleas.