My dog died last week because he was sick, but I just realized he could have died because of something I did. Is it really possible my dogs poop turned poisonous and killed him?

So, my dog had lost a LOT of weight, and was vomiting his food after eating, so we brought him to the vet and they gave us medicine for him to take, and i just had to receive it from the drive thru of the vet, they didn't take him in for any tests. He ate and drank fine, but a couple days later just collapsed and died. <br><br>For a while, I've just been feeling like I messed up so bad and there was something I could've done, and it really hurts. And a few days ago, I remembered that the medicine I had for him was in the fridge of my room, not the fridge used by my family, and I had to give it to him in his food, and I never washed my hands in between touching the medicine and the food because I thought that the medicine would have to be digested to work. <br><br>My dog had not eaten in a few days, and he had eaten my poop before, and it was outside, so his stool was visible, and there was a spot that he normally ate where he pooped. I just realized that he MUST have eaten his poop right when he started eating because it was right outside the door, and his poop would have had the medicine in it. <br><br>I told my mother about the poop eating and she said it wasnt a big deal, and my father said it wasnt my fault. But I know that medicine can not be safe to eat if it has to be digested, right? Like it can't be safe outside of a body, or else I would be able to just eat the medicine I have for him. <br><br>I've never taken any medicine whatsoever, and a lot of my family refuses to take medicine too, and they laugh at the idea of going to the vet. My father said there was nothing I could have done for my dog, and that he was going to die anyway. But I know that if he had eaten the medicine, his death would be my fault. He could've lived longer than his few months he had, but now hes gone and it's all my fault.<br><br>Anyways, im aware that poop eating is common, and not deadly or bad, but if there was medicine in there, it couldnt be good for him. <br><br>My life is shit and I can't even properly care for a dog, and I killed him. I just wish he could come back.<br><br>EDIT: I think it's clear that my dog was sick and had parasites, but his death was unexpected. The vet said he had hookworms, but didnt need to take him in for a checkup. I was told to give him medicine, but the vet didnt verify if he was eating the medicine because of course i was giving it to him properly. It's not like I/gave him a pill and expected him to digest it, and I thought that it was safe because the vet told me it was fine. I was given medicine for him and told to give it to him, and that was it, and my dog died the next week, and I know that something went wrong. This all happened a week ago, and it's not like I'm accusing the vet of malpractice, Im just saying that I was the one who had the medicine, and my dog ate it, and im wondering if my dog eating his poop would have been what killed him, if the medicine was in his poop. I had a dog and I failed to take care of him, and I killed him.