Get Your Dog Care Questions Answered by Experts
I do not recommend giving anything that contains tylenol to a dog. Tylenol is actually a toxic chemical and can cause liver failure which is not reversible. This is a personal preference as some vets will allow tylenol to be prescribed in conjunction with hydrocodone.
For sedative: You can give melatonin, calmplex 2000, or even benedryl. Melatonin dosage is 1/2 tablet. Benedryl dosage is 1mg per pound up to three times daily. Calmplex 2000 (nutrition store) varies. In his size I would start with 1/4 tablet and then increase if needed.
The problem you are going to run into here is breaking your tablet down enough to give to your dog. Your dog would only need a very small dose of the hydrocodone which is usually about 1.25-2.5mg yet the tylenol dose would be rather high even if you broke it down. Vets will give hydrocodone with tylenol based on the hydrocodone alone but I will warn you that this can cause fatal liver damage and I do not recommend giving this under any circumstances. If your dog is acting strangely out of character then I suggest a trip to the emergency vet to determine the cause because mixing of all of these sedatives can have devastating consequences.