Last summer my cat Squiggy became very ill and we were spending alot of time at the vets. 3-4 days a week for 6 weeks. He was finally diadnosed with a brain tumor and PTS. Twice during this time people came in to pick up their dogs while I was there and told me the story about how trying to save money they used Hartz flea preventative on their pooches and ended up with several hundred dollar vet bills because their dogs almnost died. These were not puppies or sick animals. I remember years ago when they came out with another flea product I think it was called blockade? and it was killing dogs left and right. But they never admitted to any wrong doing and they won’t now either.