The dog's owner received a "nasty shock" when she approached the kennel to let her Chihuahua-Maltese cross off its chain, only to find a carpet python in its place with a large bulge in its body and the dog's chain emerging from its mouth.

Volunteers from the Wildlife Information Rescue and Education Service (WIRES) were called to the home in Caniaba, near Lismore, on Thursday morning and arrived to find the 2.5-metre snake still lying in the kennel.

WIRES Northern Rivers secretary Sue Ulyatt said the volunteers cut the chain and observed the python, which is about 50 years old, for 24 hours to see if it would regurgitate the chain.

However, when it didn't, the python was taken to Currumbin Wildlife Sanctuary, where it would be examined by a veterinarian to see if it would require surgery.

Mrs Ulyatt said the dog's owner was upset but calm when she rang the wildlife service's hotline on Thursday morning.

"She realised that she had made a dreadful mistake. She hadn't thought about the possibility of a snake taking the dog," she said.

"The lady went out to let dog off the chain, but instead of the dog being on the chain, it was large carpet python.

"It's only the second incident like this we've had in over 10 years. Usually it's the other way around, the snake comes off second best."

Mrs Ulyatt said the incident occurred on a rural property, and carpet pythons were very common in the area.

The python would have strangled the dog before swallowing it whole, she said, and estimated such a meal would sustain a python for about a month.

Mrs Ulyatt said the woman was trying to do the responsible thing by chaining up her dog at night so it did not stray and potentially attack and kill wildlife.

"Chaining up a dog in a wildlife area is certainly a responsible thing to do, but the dog was too small. It should have been inside," Mrs Ulyatt said.

If the snake does undergo surgery, it will remain under care for "quite some time" before being released into the wild, Mrs Ulyatt said.

Thursday morning's incident is the latest in a string of captivating encounters this month involving pythons devouring other animals.

On March 2, an enormous water python swallowed a metre-long fresh water crocodile following an epic duel that shocked onlookers at Lake Moondarra, near Mount Isa.

Mount Isa mother Tiffany Corlis captured the contest on camera, taking a series of shots that documented the huge snake's assault on the croc.

The previous day, a python was captured on camera making a meal of a rather large possum in full view of North Lakes residents, north of Brisbane.

That spectacle drew a large crowd of curious onlookers, including amateur photograph Caroline Hubbard, who arrived to find much of the possum already in the snake's bulging stomach.

"As it was, the [snake's] tail was wrapped around a prickly branch of the tree ... and it was so thick with the body of the possum in it," she said.