A Bridgewater woman has narrowly avoided being sent to prison after she neglected her dog so badly it almost died.

Hayley Campbell, aged in her 20s, today pleaded guilty to one charge of cruelty to animals in a case Magistrate Sam Mollard described as the worst he had seen in recent memory.

The Hobart Magistrates Court heard the Staffordshire bull terrier cross Ripper weighed just 8.6 kilograms when animal welfare inspectors were called to the property.

The six-year-old animal was so weak it could only groan in response when inspectors approached it and was struggling to lift its head, the court heard.

It was also unable to walk.

The court heard it was rushed to a vet and put on a drip for several days before making a full recovery several months later.

Magistrate Mollard said he was "struggling for words" during sentencing.

Campbell was given a six-week prison term, suspended for three years.

"I must say, I don't find myself struck for words very often ... it's just extraordinary," he said.

"I've owned dogs for 65 or more years. I know enough about dogs to know this sort of thing doesn't happen suddenly.

"Just how somebody would have possibly allowed this dog to get in this condition causes me to grasp for words."

Magistrate Mollard demanded Campbell tell him "what was going on" with the animal, because "it looked like it hadn't had a decent feed in weeks".

The court heard Campbell had told inspectors, who also described the case as one of the worst of neglect of a dog they had seen, that her pet "was always thin" and "a fussy eater".

Campbell, who was unrepresented, claimed she provided her pet with food and water, but that he had no appetite and she "didn't know what else to do".

"I feel terrible ... he was a family dog. I wasn't paying enough attention. I had a lot going on," she said.

'This unhappy animal was almost dead'

But Magistrate Mollard questioned Campbell's version of events, and told her alarm bells should have been ringing.

"What about the vet? Worms can destroy an appetite, did you know that?" he said.

Staffordshire bull terrier cross Ripper was rescued by the RSPCA. ( Supplied: RSPCA )

"Are you aware you could be fined $15,000?

"It was absolutely clear this dog had been neglected for a significant amount of time.

"If you can't afford the vet, go to Kmart and buy some worming tablets."

Magistrate Mollard said animal mistreatment was unfortunately not uncommon but he was shocked by the case before him.

"Very unhappily, these cases are not that uncommon, and it's not just dogs, it's goats, sheep ... often they seem to be horses," he said.

"Recently, I haven't seen anything quite as bad as this. It really is the sort of thing that ought to attract community attention.

"To describe this as a shocking case is hardly going to get me accused of exaggeration.

"This unhappy animal was almost dead."

Campbell listed her occupation as a mother on social security.

She was fined the RSPCA's costs of $943, as well as court expenses, and ordered not to own a dog for the next three years.