Nine animal welfare groups have banded together to ask the authorities to place more rules on how pets are put down for behavioural issues - a move which several veterinarians said was impractical.
According to the proposal sent to the Agri-Food and Veterinary Authority (AVA) and the Singapore Veterinary Association on Monday, they want vets to carry out a series of steps before euthanising an animal.
The "Proposed Euthanasia Protocol for Vets" includes asking them to verify if the animal has had basic obedience training, and if it was adopted, to check whether the pet's previous owner wants it back.
The groups, which include Action for Singapore Dogs (ASD) and the Animal Concerns Research and Education Society (Acres), were spurred into action by the recent controversy over a seven- month-old healthy puppy which was put down by its adoptive owner.
The British owner, Ms Alison McElwee, who works in a health-care clinic, says that the puppy, Tammy, was aggressive and had bitten her four-year-old daughter and two adults.
She also claims that Ms Ada Ong, who gave Tammy up for adoption after rescuing the dog from the streets, declined to take the animal back.
Ms Ong, an assistant project manager, disputes this and has begun legal action against Ms McElwee for breaching their pet adoption agreement.
ASD president Ricky Yeo said the proposal could have saved Tammy, in this case by requiring the vet to check with Ms Ong before putting the dog down.
"It acts as a guide and checklist to ensure that the vet obtain relevant and sufficient information before making such an important decision as taking away a life," he said.
But vets said some of the proposed rules were impractical and would make their job too onerous.
Dr Lee See Yang, a vet with seven years' experience, said: "How is the vet supposed to verify who owned the pet before? What if the adoption happened a long time ago or the animal had more than one previous owner?
"The person who adopted the pet assumes responsibility for it and should make the decisions. If you ask vets to always go back to the previous owners, then the current owner is just a fosterer, not an owner."
Current protocol requires vets to confirm ownership of the pet, satisfy themselves that euthanasia is reasonable and then advise the owner of the various options before killing the animal.
However, the decision rests entirely with the pet owner.
The AVA, which regulates vets, confirmed Monday that it had received the animal welfare groups' proposal.
In a previous statement, it said that the clinic which euthanised Tammy had followed the correct protocols.
The authority added that vets "may at times be called upon to euthanise an animal for various reasons, such as to alleviate their suffering, or if they are aggressive".
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