© A Current AffairCarrie Barlow is being sued for $100,000 over an online review she left for a vet.
An unhappy review posted online has sparked a four-year legal battle and cost one family $100,000.
Carrie Barlow was walking her dog Valentine four years ago when another dog ran out of a nearby house and bit Valentine on the head.
Ms Barlow took her pooch to her local vet, where she said she had been a customer for two years.
Valentine needed two stitches, medication, and a dose of antibiotics, and was promptly seen to by staff.
"I went to pay the bill, and the vet said to me, 'oh, that really added up didn't it, I'm sorry about that'," Ms Barlow said.
"And I didn't think much of it, we paid the bill, we left."
Days later, after looking back over the bill, Ms Barlow said she decided to query the $427 charge. © A Current AffairCarrie's dog Valentine was injured by another dog and treated at the local vet.
She admitted to A Current Affair she had a heated discussion with the practice manager about the bill, which ended with Ms Barlow asking for Valentine's records so she could take her business elsewhere.
When she returned home from picking up the records, there was a letter inside from practice owner and head vet Allen O'Grady.
"The letter was talking about the other services that the veterinary practice offered," Ms Barlow said.
"And it said that (they) wouldn't be able to provide those services to me and my family in the future." © A Current AffairMs Barlow queried the vet bill and eventually said she would take her business elsewhere.
Ms Barlow took to Twitter and TrueLocal to post reviews of the clinic.
She also snapped a photo of the letter and shared it on Facebook.
"I was writing about the fact that I thought that I had been overcharged, and that the service was very disappointing, and that we weren't happy to receive a letter like that after putting so much money through the business previously," Ms Barlow said.
Days later, a legal letter arrived on behalf of Dr O'Grady, demanding Ms Barlow remove the posts, issue a public apology, and pay a sum of $6300. © A Current AffairPractice owner Allen O'Grady said in a letter he would not be able to provide other services to the family in the future.
Ms Barlow said she had been willing to apologise, but refused to pay the money.
She deleted some, but not all, of the posts.
She claimed Dr O'Grady's lawyers then sent a follow-up letter asking for $17,000.
Ms Barlow is now being sued by Dr O'Grady and his vet practice for defamation and $100,000 in damages. © A Current AffairMs Barlow posted a negative review on TrueLocal, and another on Twitter.
Dr O'Grady claims Ms Barlow defamed him seven times over a 10-day period in 2014, damaging the business and his reputation.
Ms Barlow claimed the merit of the case had not yet been tested.
"No-one's looked at my defences of honest opinion, and substantial truth," she said.
The matter was listed for trial last month, but days before, Dr O'Grady's lawyers said he was unwell and would not be fit for trial until February. © A Current AffairDr O'Grady claimed he was defamed by the reviews.
"It's cost us somewhere in the vicinity of $100,000 just to defend this to date and it hasn't gone to trial yet," Ms Barlow said.
Derek Wilding, from the Centre for Media Transition, said more everyday Aussies were heading to court over things that had been posted online.
A Current Affair approached Dr O'Grady for comment, but was referred to his lawyer.