The Northern Territory News reports the elastic on the size 10, lacy black G-string became wrapped around the intestines of Baxter, a two-year-old cavalier King Charles spaniel.
Baxter's owner, who was too embarrassed to be named, said she rushed her tiny pooch to the University Avenue Veterinary Hospital in Palmerston at 9pm on Saturday after she became concerned when the ''usual pig when it comes to food'' was refusing to eat and started vomiting.
Her fears were recognised when an X-ray revealed something was obstructing the 9.7kg spaniel's bowel and vets said if he wasn't operated on immediately he would be lucky to survive the night.
But the $2200 life-saving operation turned to hysterics in the surgery when vets found a piece of underwear was to blame for Baxter's misfortune. The dog's owner said she couldn't believe it when the vet rang her at 3am on Sunday following the surgery to say they'd found women's undies.
'When she rang back and said that it was a ladies black g-string I couldn't believe it,'' she said.
''He had 20cm of elastic all through his intestines, they had to untangle it all.
''Now we know he is okay we can have a laugh about it but he is very lucky.''
She said it was not the first time the spaniel had ran off with her underwear.
''The dog's a real guts and will eat anything,'' she said.
''He's taken off with undies before but we'd learnt not to leave them around.''