The Maltese and shitzu cross, called Bingo, was covered in blood, leading owners Robyn and George Howard to believe he had been stabbed.
It is unclear why the dog was harmed.
The Howards’ daughter Tracey Howard said everyone is shocked by the incident.
“We still don’t know if it was random or intentional,” Tracey said.
“We posted about it on social media because we wanted people to know, in case it was just random.
“I found out (about Bingo) when my son rang me and said the dog was covered in blood, and he thought it might be dead.
“My daughter checked first and then rang me and confirmed the dog was dead, so I went over.
“It looked like he had been stabbed twice, but there’s also a chance he was burned.
“When my dad was burying him, we noticed his hair was peeling off.
“We’re not sure if he was burned (by flames), or had something like acid poured on him.”
Murray River Police District Chief Inspector Michael Fuller said the dog was discovered dead Saturday afternoon.
It in unknown how long the dog has been dead when he was discovered, but Tracey said parents of her neighbours did report hearing noises outside their home about 2am or 2.30am that morning.
Chief Insp Fuller said the owners reported last seeing the dog alive and well about midday Friday.
Chief Insp Fuller would not officially confirm the dog’s cause of death.
“The dog, when located, had an amount of blood visible however it was not clear what had caused the dog to become deceased.
“However, it did not appear to be a death by natural causes.
“Police are seeking public assistance. If anyone heard anything or saw anything suspicious, including any persons around Fowler St, Deniliquin between Friday and Saturday when the dog was found deceased.”
Tracey said while Bingo has normal small dog traits like barking, she said he was overall a loving dog who was adored by her parents and her own children.
Anyone with information is asked to contact CrimeStoppers on 1800 333 000 or Deniliquin Police on 5881 9299. Calls to CrimeStoppers can remain anonymous.