Marley gets a milky drink alongside his tea every night (60%milk40% water) no harm done, can't tolerate cheese though

Another one is human oatmeal raisin cookies. Callie will stand on his head to share those, with no ill effects. Think it depends on the dog, their weight, and general health.

I used to have a GSD who loved avocados. We had a large tree in our garden and when they were in season, every morning she'd eat at least half a dozen, without any ill effects. Walnuts are also said to be toxic for dogs, but my previous two used to collect them from under the tree. My larger dog would crack the shell and share the nuts with my little one. It was quite fascinating to watch how they cooperated with each other to get what they both wanted!

Yes, size is extremely important.

Example. Nigredo got a chicken thigh bone a few days ago. I was eating at the table, and dad yelled in pain so I got up and rushed upstairs to see what was wrong (he had stubbed a gout toe, no biggie) and left the bones on the table. I was helping him limp back to his bed and fetched his meds etc.... took about 7 minutes in all.

Well, the cats worked in unison with Nigredo. They knocked the bones down, and he nabbed one. I saw him with it when I came back, he was jetting downstairs to eat it before anybody noticed he had taken it. Jade was laying on the couch, suppose she wanted nothing to do with this mess they were making.

He responds to a drop it or leave it command pretty well, but when there is a food item, it can falter. That has held us back in so many ways. This time, it faltered. As I went to try and pry his jaws open, realizing he wasn't going to drop it... he swallowed it whole.

He is greedy, has been known to swallow entire raw chicken thighs whole, is 90 lbs with a big head and throat etc., and was perfectly fine, but it might have choked a smaller dog had they tried to do this. Size is a HUGE (no pun intended) factor.