Vicki Lee Edwards pleaded guilty in Wollongong Magistrates Court on Thursday to one charge of aggravated animal cruelty against a female Staffordshire crossbreed dog in her care.

The court heard that on August 15, an RSPCA NSW inspector attended a property in Mount Warrigal in response to a complaint about a dog.

Upon arrival, the inspector observed the dog lying stretched out against the rear fence, with a large amount of pus and blood oozing from a lump on the bridge of its nose, between its eyes.

The dog was also emaciated and was taken away for veterinary treatment.

On August 23, the inspector returned to the property and interviewed Ms Edwards, who said she had been reluctant to take the dog to a vet as she feared being told the animal required euthanasia.

She also said she felt the dog wasn't suffering.

The seized dog was later euthanased as it was deemed too cruel to keep her alive due to the severity of her medical conditions.

On Thursday, Ms Edwards was convicted on one charge of aggravated animal cruelty, resulting in a $5000 fine, plus $456 in court costs. She was placed on a two-year good behaviour bond.

She was also ordered to report to Wollongong police within seven days for fingerprinting and was banned from owning, purchasing, acquiring or caring for any animal for 20 years.