My six year old maltipoo Koko vomited blood, I mean lots of blood last night. Two days ago, I went to Target and saw Hartz flea collar on sale. Since I needed a flea collar, I was thinking “why not?” This was the worst mistake I have ever made for my lovely baby Koko. For first few hours of wearing the collar, she seemed okay, but didn’t eat her supper. I thought she was just being picky, cause she does that to me often, wanting treats instead of dry food. No big deal, so we all went to bed. Next day, she sniffed at food, but didn’t eat or drink much water. Again, since she is a really picky eater, I thought she was giving me one of her “I want cooked chicken” fit. So I gave her treats, but she didn’t even eat that. Then, I knew something was wrong. She never refuses her chicken jerky (Dogswell brand)!!! Koko was also lethargic and didn’t move much…. Few hours later, she threw up and vomited lots of blood. That was yesterday, so today I took her to the vet and she prescribed some meds to coat her stomach and calm down her system. But I am so worried that it might not be enough. Koko always had very sensitive stomach. Therefore, her diet is very strictly limited and same things everyday. Only thing I did differently was putting the flea collar on her. I should have never put the collar on her….. How could they make such horrible thing and make money from it? I read other posts and now, I am scared of renal failure….. Im taking her back to the vet tomorrow and get more tests done.