Rat poison is a common toxin that animals get access to and it can be fatal, however it is one of the few poisons that we have an antidote for so if there is any possibility that your dog/cat has had access to it the most important thing is to get them to the vet as soon as possible. With any possible poisoning speed is of the essence, if the animal is brought to the vet within 2 hours of ingestion/access to the toxin then vomiting can be induced with a simple injection. Even if it has been longer than 2 hours we can try to limit the absorption of the toxin and take measures to prevent or limit the damage caused.
Ingestion of rat poison causes bleeding as the toxin works by interfering with the bloods ability to clot. Animals can present in different ways depending on where the bleeding occurs and how much of the toxin they ingested. Usually there is a lag period with rat poison before the effects are seen as the animals clotting factors are used up and then they cannot produce anymore because of the toxicity and bleeding occurs (can see bruising, swollen abdomen if bleeding internally, difficulty breathing if bleeding into lungs/chest, pale gums, blood in urine or faeces or vomiting blood, lameness if bleeding into joints). Bleeding can occur immediately if a very large amount of the toxin is ingested. If you know the type of rat poison ingested this can help the vet decide on the treatment protocol so if you have the packaging bring it with you! Rat poison is one of the few toxins for which we actually have an antidote so even if the poisoning occurred hours or even days ago we can still give the treatment to prevent the secondary effects and potential damage. Vitamin K is the treatment to prevent bleeding and this is administered initially by injection and then followed up with oral Vitamin K for a number of weeks depending on the type of poison. The blood clotting times can also be checked to determine if they are normal or still being affected by the poison ingestion.