I hope I can help with your question and do message me if you have any queries regarding my answer/advice.
I am sorry your dog has eaten rat poison.
Some anti coagulant rodenticides require a significAnt amount to be eaten before being toxic
to dogs, however, some can require only a small amount to be ingested.
Immediate decontamination through vomiting is recommended and there is a window of 4 hours post ingestion where this can be successful. As you have not had success using the hydrogen peroxide and have tried it several times I would not repeat this, if the ingestion still occurred less than 4 hours ago I would seek veterinary attention to induce vomiting.
Anticoagulants exhaust the supply of Vitamin K in the body so depending how much Vitamin K there is in an animals body the effects of the poisoning can take 5-7 days to be seen.
So monitoring of the clotting times is required and tis should be done today and tomorrow and over the next few days.
If you seek veterinary attention then take the rat poison container with you.
Vitamin K injections /tablets should be used knowing that there is a deficiency so testing should be performed.
Dr Dan Makin