This x-ray of Chico the dog appears to show a spare rib, but the anomaly was actually down to the greedy pet swallowing a six-inch cow rib bone whole!
PDSA vets were gobsmacked that Chico, a one-year-old Mastiff-type, had managed to wolf it down without causing himself an injury.
Susie Hermit, Senior Vet at PDSA's Glasgow Shamrock Street Pet Hospital, said: "I've never seen an x-ray like it before, the position of the bone really did look like Chico had an extra rib!
"Amazingly he'd managed to swallow the bone whole but didn't seem to be in any pain. However, we knew we had to carry out emergency surgery to remove it because it could have caused a life-threatening tear to his stomach or intestines."
Chico's owner, Craig Anderson from Newlands, Glasgow, said he had bought the rib bone as a treat for his beloved pet.
"I thought if I supervised him it would be fine but he literally swallowed it in one mouthful.
"He seemed fine but I knew he wouldn't be able to digest it properly so I took him straight to PDSA."
Thankfully Chico has gone on to make a full recovery, although bones are now firmly off the menu.
Craig added, "I was so worried while he was in the operating theatre. It's a miracle the bone didn't cause any damage. I'm so grateful to PDSA for the amazing care they gave to Chico, it's something I'll never forget.
"It goes without saying but I don't give bones to him anymore after this. It's definitely a case of once bitten twice shy."
Susie added, "Chico is very lucky. We don't recommend bones to be given as treats because they can cause digestive tract damage and blockages. Surgery is usually needed to remove the blockage and, in some cases, the damage is so serious that it can be fatal."
Thanks to funding from players of People's Postcode Lottery, PDSA is educating pet owners about pets eating inappropriate foods and objects, and how to keep their animals safe.
Bones were the most common items removed from pets' stomachs by PDSA vets last year, with 59 cases seen. Other strange items swallowed by pets include stones (28 cases) and corn on the cob (29).
PDSA vets say training pets from a young age in basic commands like 'drop' and 'leave' can help to get them to let go of inappropriate objects if owners catch them in the act.