The Assie family's Staffy Terrier 'Boof' was in the family's Casey Street backyard when Morgan Assie went off to work at 6.50am on Saturday morning.

But when Jane Assie went outside to say good morning an hour later she noticed something was wrong.

"Boof didn't come to the door which is very unusual," she said.

Mrs Assie found her very-sick pet in the yard and with the help of a friend who'd been staying with her rushed him to Mulberry Lane Vet Hospital.

Within minutes of arriving at the vet Boof was dead, suffering seizures before he died.

Devastated, the Assies returned home only to find the friend's dog, a German Shepard named Sam, having a seizure at the gate.

They rushed back to Mulberry Lane where veterinarian Judith Carney and her team worked on Sam and the Assies' other dog Zeus.

Suspecting a poisoning, Sam's stomach was pumped and the vets administered a drug to Zeus to induce vomiting.

Dr Carney said she noticed hexagon shaped pieces of bread inside the German Shepard's stomach, at which point she became "highly convinced" it was a poisoning.

"It makes you feel quite sad that someone would be so vindictive," she said.

Sam recovered from the poisoning and Zeus was given fluids.

Dr Carney said she suspects the bread found in the dogs' stomachs was soaked with Strychnine, a poison often used to kill characters in works of fiction as it is tasteless and odourless.

In the last six months, Dr Carney said she's treated animals she suspects were poisoned using rat bait, but this is the first instance of Strychnine she's seen.

"This is a new spate of a different poison," she said.

"It's not a nice way to die."

Orange police attended the Casey Street property on Saturday morning.

Chief Inspector Peter Atkins said initial investigations suggested the dogs had been poisoned and police were awaiting test results on Tuesday.

He said police had spoken to neighbours and none were being treated as suspects.

Jane Assie said she doesn't believe her family are the only victims.

"There have been a few incidents of this," she said.

While losing their "beautiful" pet has shaken the whole family, Mrs Assie said she's horrified to think it could've been her two-year old Addison or four-month old Lola who picked up the bread.

"There's a swing set in the backyard - our two-year old 100 per cent could've picked it up," she said.

"They easily could've murdered our daughter," she said. "If Boof was annoying someone they could've come to us and said something.

"We've never had any problems with any neighbours, now every car going past you think 'did they do it?'"

Inspector Atkins urged anyone who saw anything suspicious between 6.50-8.15am on Saturday morning to contact Orange police