I used Hartz on my dog, the flea and tick oil, and she had a seizure that lasted over 1 and a half hours. I took her to the vet ER and they were finally able to stop the seizing. They had to sedate her for the night so she would not have more. She has not been the same since. When I picked her up in the morning a man was there who told me he had a lab and his lab did the same thing after using this product. I am hoping that people will see it is so worth it to use vet approved products on their pets. I have written the company and told them that they need a warning lable and asking to be reimbursed for this. I will let you know what happens. Please if you love your animal do not use these products.