You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
The family - based in Cust - posted online saying their poodle-pomeranian crosses Bonno and Clyde were found poisoned, believing it was the result of a neighbourhood dispute.
Clyde did not survive. But Bonno returned home yesterday.
Ben Davidson, of Rangiora Vet Centre which treated the animals, said the dogs were found with nerve injury signs such not being able to control their movement, being shaky and collapsing.
"It has been a very up and down case," he said.
The incident happened after the two beloved dogs set out to chase rabbits on Friday evening. Brooke Wallis was called by a neighbour who said they could hear the pets "yelping" from a local property.
Driving to the property with her family, they whistled to the two small dogs to call them out.
They didn't rush back to their owners but Wallis could hear them howling, she said on Facebook.
"My husband decided to drive up to the culprit's home to check, they didn't appear to be home," Wallis wrote.
"He found our dogs in a holding pen at their home, with their legs tightly bound with baling twine upside down. My husband broke them free and rushed them home."
Davidson said the case was unusual given common poisoning includes predator bait or algae.
"We see lots of poisonings but this is a wee bit unusual in that it's a prescription drug that was the cause of the poisoning, one that's normally used to treat epilepsy," he said.
The family declined an interview, but posted on social media today to thank people for their support.
In an earlier post which first alluded to the poisoning, one owner said Clyde - the deceased dog - was found eating balls of mince covered in powder.
"We are absolutely devastated. Our daughters are 14 and 7, and they've spent their weekend sobbing and scared that someone could come to our home and hurt our family in this way," they said.
The family have made two complaints to the police, who are investigating.
"Police have received two reports in relation to animal welfare offences against dogs in Cust, the first on 1 May and the second on 2 May," a spokesperson said.
"Enquiries are ongoing, however no arrests have been made or charges brought at this stage."