Get Your Dog Care Questions Answered by Experts
You really need to take a fecal sample to your vet and have them analyze it. Different wormers work for different worms. It sounds like you are describing hook worms or roundworms but you cannot be sure. Since different wormers work for different worms, you will need to see the vet, have them analyze some fecal matter and give you a dewormer that will WORK. Over the counter wormers are not terribly effective.
Let me know if you still have questions.
Yes. I do think so. Once you treat it, you can prevent it by getting your dog on a montly hearworm preventative because it contains worming medications that treat these types of worms.
No. The worms are not contagious to humans. There are a couple that are but we will not actually get worms from them, just some skin irritation.
You do need to see the vet to have this taken care of even if they are not contagious to people.