Have you or your vet contacted the company? Are these the ones you gave?
Milk-Bone Brushing Chews Daily Dental Treats, Small/Medium Value Pack, 14.14 oz - Walmart.com Did you use the mini size? This is such horrible news, they have been given the (VHOC) Seal of Acceptance and shown effective for reducing tartar, but it sounds like they aren't completely digestible. Thanks for the warning, and glad you were able to take Ringo for help right away. Hope he has a speedy recovery!