Things you can do help in the meantime are:
1. Contact your veterinarian immediately: Time is of the essence when it comes to theobromine poisoning, so it's important to contact your veterinarian as soon as possible. They will be able to advise you on the best course of action and provide treatment if necessary.
2. Induce vomiting: If your veterinarian advises you to do so, you may be able to induce vomiting at home. This can help to remove the cocoa powder mixture from your dog's stomach and reduce the risk of further absorption of theobromine. There are a few different ways to induce vomiting, but one common method is to give your dog 3% hydrogen peroxide by mouth (1 tablespoon per 15 pounds of body weight). Be sure to only do this if your veterinarian has advised you to do so.
3. Provide supportive care: While you're waiting for your veterinarian to see your dog, you can provide supportive care at home. This may include giving your dog small amounts of water to drink, keeping them warm, and monitoring their breathing and heart rate.
Do not attempt to medicate your dog unless advised by your veterinarian. Some human medications can be toxic to dogs, so it's important to only give them medication that has been prescribed by a veterinarian.
The prognosis for theobromine poisoning depends on the amount of cocoa powder consumed and the severity of the symptoms. With early treatment, most dogs can recover from theobromine poisoning.