Last night, Honey and I were out most of the evening and when we came home at 9, we went straight to bed. Usually, Dobby goes to sleep with us right away, while I read for a while. But last night he couldn’t settle down. He kept chewing his new rawhide bone like a madman. Every once in a while, I’d get up and try to coax him into bed with me, to no avail. Finally, I gave up and fell asleep to the sound of his chew-suck-chew on the bone.
I woke up at 1:30am to him still chewing away. So I took him outside for a potty break. He came in and still wouldn’t settle down. He chased Brudder around a bit, let Brudder try to hump him, chewed on his bone, ripped up some kleenexes — it would not end! I held him close and checked his heart rate from time to time, trying depserately to figure out what was wrong with him. His heart rate wasn’t too unusual for a dog his size, but I’m not veterinarian!
So I got up this morning to discover a chewed up and empty box of Toblerone chocolate that Honey had gotten me for Christmas. Apparently, the dog ate the chocolate last night, probably before we got home. That would explain his excitability throughout the night.
I called my dad, who called his vet on three-way and we had a lengthy conversation with the vet tech about what symptoms of toxicity I should look for and if I should take him to his own vet. It turns out that milk chocolate isn’t as bad as, say, baker’s or semi-sweet or dark chocolate. Honey found the following on the internet:

The truth is chocolate contains theobromine that is toxic to dogs in sufficient quantities. This is a xanthine compound in the same family of caffeine, and theophylline.
The good news is that it takes, on average, a fairly large amount of theobromine 100-150 mg/kg to cause a toxic reaction. Although there are variables to consider like the individual sensitivity, animal size and chocolate concentration.
On average, Milk chocolate contains 44 mg of theobromine per oz.
Semisweet chocolate contains 150mg/oz.
Baker’s chocolate 390mg/oz.
Using a dose of 100 mg/kg as the toxic dose it comes out roughly as:
1 ounce per 1 pound of body weight for Milk chocolate
1 ounce per 3 pounds of body weight for Semisweet chocolate
1 ounce per 9 pounds of body weight for Baker’s chocolate.
So, for example, 2 oz. of Baker’s chocolate can cause great risk to an 15 lb. dog. Yet, 2 oz. of Milk chocolate usually will only cause digestive problems.

He chewed off the part of the box that indicates the amount of chocolate inside but my guess is he didn’t eat more than 3 ounces and he weighs 14 pounds. Whew.
He’s been pretty hyper all morning, just as he was last night, but shows no other dangerous symptoms (such as vomiting, tremors or diarrhea). Within the last hour he’s finally curled up in his sun chair for a nap.
We’re keeping a close eye on him for the rest of the day and night of course but I think he’s in the clear. He gave us a pretty bad scare there. Yikes.