Jack Russell Toby bit off more than he could chew when he devoured the morning post and the mashed up paper and envelope glue set, locking his jaws together.
Owner Gill Bird was stunned when she returned home to discover her mischievous pet could not open his mouth.
After Gill, 41, tried unsuccessfully to prise open his locked jaws herself, she drove him to the vet.
Mischievous: Toby the Jack Russell found his jaws clamped shut after glue from the post he had been chewing set
Staff there tried to force open the dog's jaws but had to sedate anxious Toby in order to pick away at the glue and open his mouth.
Toby's jaws had become stuck together after he ripped up the morning post when it landed on the doormat at Gill's home in Lee-on-the-Solent, Hampshire.
The envelope glue had become sticky and, mixed with the paper, had set like papier-mache, locking Toby's upper and lower jaws shut.
Gill said: 'Toby likes to attack the post. When we hear the letter box go we have to run and get to the post before he does.
'I came home with some fish and chips for lunch. I went to give him a chip and wondered why he wouldn't take it. He was drooling. I thought it was strange.
'All this paper was mashed around his teeth. It was absolutely stuck to it. I tried to stick my finger in his mouth but he couldn't open it.
'He had bubbles and saliva coming out of his mouth and he had a strange look on his face.
Unstuck: Toby, pictured here with his owner Gill Bird, had to be sedated as a vet worked to remove the glue from his jaws
'It's just really bizarre. I can't help but laugh.
'He is the most fantastic dog. He's very lively. He's loved by everyone, he's so much fun.'
Ian Wooding, a veterinary surgeon at Alver Vets, in nearby Stubbington, described it as a 'very unusual case'.
He said: 'I couldn't believe it until I saw it, his mouth was stuck together. It was very funny - although not for the dog, of course.
'He had chewed on an envelope and he chewed it up to the point where the mashed up paper and the glue had gone all sticky.
'At first I thought I'd get his mouth open without a problem - but I soon realised it wasn't budging at all.
'We tried to scrape some of it out but the dog was getting quite worked up. He was growling and I think he would have bitten me if he'd been able to.
'We decided to sedate him but even then it took the nurse and I a good 10 minutes to scrape all the paper out of his teeth and get his jaw open again.
'I've never seen anything like it. I hope he's learnt his lesson - but I doubt it!'
Toby returned home a few hours after the sedation wore off, fit and well.
Read more: Post-chewing dog left in a sticky situation after envelope glue locks his jaws together | Mail Online