i had to take my dog to the vet today because she has been itching really bad. i found out that the hartz flea and tick drops i used on her really hurt her skin. after talking to 3 different vets they all said hartz is a really bad medicine. i am wondering if anyone else has used this and if it hurt there dog and also how long it took before they felt better. i am giving her benedryl for the itching but they said that is about all i can do. i also found out she might have a thyroid problem. i should have the test results back tomorrow. they said if she does she has to be in medicine for the rest of her life. she has lost quite a bit of her hair which i thought was shedding and so did the vets everytime i called but it turns out it is not also she has gained 10 pounds in 2 months and that is another reason they think it is a thyroid problem. i am wondering if anyone elses dog has this and if you noticed a difference after they were started on the medicine.she is a german shepard