Boxers dumb ? Lol I could not agree more.
A few years ago I was over a friends who owns 2 boxers. I took a few dozen fresh clams for him and I to eat. Well guess who ate many of the shells ? Yep, his two boxers. We opened them in the garage and tossed the shells in a 5 gallon bucket. Stupid was leaving the doors open. Good thing they were cherry stones. He called his Vet and he suggested to keep a close eye on them to make sure they "pass" they did.
Yep pretty dumb, but makes for plenty of entertainment!