Working as a vet tech the amount of objects I’ve seen surgically removed from cats and dogs is astonishing! Puppies are generally the worst perpetrators of this, but older dogs can get into mischief too, and cats as well.
The worst things your dog can actually munch on are things like cork. It’s organic and does not show up in x-rays or ultrasounds. It looks passive, non-existent, but can lodge within the digestive tract and block it up. Corn cobs, big problem too. We see them as discardable items, dogs see it as a treat. Thread and cats! Dimes, wrapping ribbon, things that we regard as benign can be pretty tempting.
I had a kitty come into rescue. I caught him eating broom bristles. He started throwing up blood. I took him to my local rescue friendly vet and the x-ray showed something. This cat was dumped at a NYC shelter just before Christmas. One of my funders Ron Howard paid for his abdominal surgery and when they got in there they found two wads of wrapping ribbon. He was deemed a PICA kitty, but he really wasn’t. I think he was so hungry and bored that he got himself into a $1,600 mess. I don’t know if the owners knew about this before they dumped him at Animal Care and Control, but it’s a lesson for any pet owner. Keep weird objects out of reach at all times.