Oscar, 10, had to be rushed to the PDSA’s Pet Hospital for emergency treatment.
The beloved pet was given a general anaesthetic so that vets at the Blackpool branch could remove the “papier mache-like” substance that had glued his jaws shut.
Vet Rachel Smith said: “Oscar was brought into us in an extremely distressed state.
Chewing the leaflet had turned into a sticky wallpaperlike substance inside his mouth, which had glued his teeth together.
“Once he was anaesthetised, we used our dentistry equipment to remove it from his mouth.
“Thankfully he made a good recovery and he was able to go home the same day.”
Owner Pat Finnerty, 55, of Blackpool, said she had gone shopping with her daughter Emily and returned home about an hour later to find Oscar in an extremely anxious state.
She said: “I brought him back a treat and he wanted to eat it, but he couldn’t open his mouth and there was all this saliva everywhere.
“When I looked closer at his mouth, I could see that he couldn’t open his jaw but I didn’t know what it was.
“I then noticed a chewed-up leaflet and realised what had happened.”
They contacted PDSA and were advised to bring Oscar straight in.
Pat said she was hugely grateful to the PDSA for the treatment Oscar received and now takes extra precautions to prevent him going for the mail again.
She said: “He hasn’t learned his lesson and, given the chance, he still tries to get the post.
“I now take extra care to shut the door between the lounge and the front door when I go out.
“Oscar means the world to us, so I don’t want him getting into trouble again.”
PDSA vets advise taking steps to ensure pets can’t get at any mail such as keeping hallway doors shut or using a letter cage on the inside of the front door.
Letters and leaflets dropping through the door can be particularly enticing for dogs as they often like to explore new items with their mouth.