Thanks for your patience. As you likely already know - chocolate is toxic to dogs, however it depends on the size of the dog, the amount ingested and the type of chocolate. While your boy is big at 80lbs and only ate milk chocolate, unfortunately he could have ingested up to 25 - 30 ounces of milk chocolate by the time we take the candy shell out of the equation. As such, that is definitely enough to cause a severe chocolate toxicity. Because chocolate toxicity can take 4 - 6 hours to show up as symptoms, it could well be that his real symptoms of this ingestion are yet to appear. Symptoms can include increased thirst, hyperactivity, restlessness, but also twitching, muscle spasms and even seizures. As such, you really would be best playing it safe in this instance by getting him to your local ER vet where they can give him IV fluids and activated charcoal to minimize the chances of a severe toxicity here (he has had enough chocolate for a severe toxicity).
If he currently seems fine and you would rather continue monitoring him, then you will need to keep a close eye on him for another 2 - 3 hours yet if you can. In particular, please keep a close eye on his mucus membranes, capillary refill time and respiratory rate as follows:
Mucus membranes - flip his lip and look at the color of his gums. They should maintain a nice salmon pink color. Get him to the emergency Vet if they appear white or very pale pink, or if they are a dark deep red color.
Capillary Refill time - this measures blood perfusion and test this by putting your thumb on his gum to apply pressure. After you release your thumb you will see the gum blanch. Capillary refill time is the amount of time it takes (in seconds) for the gum to return to a healthy pink color from the blanched white color. If 2 seconds or less don't worry - if it is taking significantly more time, again - off to the emergency Vet.
Respiratory Rate - if he is continuously panting throughout the night, this is a sign of shock and or pain and a signal for a trip to the emergency Vet.
Best of luck with your boy and hopefully he will only have the symptoms of increased thirst, but keep a close eye on him. I hope all of the above makes sense? If you have more questions or if I can help in any other way, please do not hesitate to ask! If you would like to accept my answer, please press RATE OUR CONVERSATION (I am not compensated in any other way). Bonuses are always welcome. Thanks! I hope to work with you again soon!
PS: If you have additional questions after you rate the question, you are welcome to request me for additional conversations if I am on-line or by beginning your question "Dr. E..." or "Pet-doc..." and others will leave the questions for me.