Animal welfare groups in Singapore are upset over a Housing Board notice that asked some dog owners in Ang Mo Kio to consider "debarking your dog through surgery". The notice has since been taken down.

Just what is debarking, which the Agri-Food & Veterinary Authority (AVA) described as a "solution of last resort" in an online brochure? We take a look:

1. Debarking does not silence a dog completely

The procedure sees a veterinarian remove a section of a dog's vocal cord to reduce the volume of its bark. This is done in one of two ways after the animal is anaesthetised - through the dog's mouth or via an incision in the larynx.

The procedure does not silence the dog completely. Instead, it lowers the volume of the bark, and makes it less sharp and piercing. A 1990 Straits Times report described the sound a debarked dog makes as "a small squeal", while a New York Times article called it a "raspy squeak".

2. There is risk involved in the surgery

Debarking a dog results in pain and discomfort immediately after the operation. If there are complications, the pain may recur after the dog has recovered. A debarked dog can regain its bark if the vocal cord regenerates but performing the procedure multiple times on the same dog can increase the risk of complications.

Excess scar tissue can also build up in the throat, making it hard for the dog to breathe. There could also be an increased risk of physical harm to the dog, as it is unable to ward off threats by vocalising.

Being unable to communicate as effectively as before can also cause some dogs to be frustrated, which could lead to destructive behaviour.

3. Advocates say debarking a dog may save its life

Faced with the choice of having to put a dog down or debarking it, pet owners facing complaints tend to go for the latter option.

Some also say that dogs don't notice that the sound they make has been reduced. As they are not constantly being disciplined for barking, advocates say that debarked dogs are happier.

Veterinarian Sharon L. Vanderlip, who has been performing the operation for more than 30 years, told The New York Times in 2010: "They recover immediately and they don't ever seem to notice any difference. I think that in certain cases it can certainly save a dog from ending up being euthanised.

"If properly done, they behave totally the same afterwards and don't seem to have any health problems."

There could be medical reasons for debarking as well, like when a dog has a tumour that needs to be removed.

4. Debarking is banned in Britain and parts of Europe and the United States

Performing the procedure, unless medically necessary, is prohibited under the European Convention for the Protection of Pet Animals, which has been signed and ratified by 23 countries, including France, Italy and Denmark. It is also banned in Britain.

In the United States, debarking is banned in the city of Warwick, Rhode Island, and in four states - Massachusetts, New Jersey, Pennsylvania, and Ohio - under certain circumstances.

Australia allows debarking in situations where a dog is deemed a public nuisance, in accordance with its Code of Practice for Debarking of Dogs. The code however states: "This Code does not approve of debarking as a substitute for proper care, management and training of a dog."

5. Pet lovers in Singapore want it banned here

Society for the Prevention of Cruelty to Animals (SPCA) executive director Corinne Fong told The Straits Times in 2012 that some pet lovers wanted laws to ban certain practices in the pet industry, including debarking.

Local experts My Paper spoke to in 2009 were up in arms over pet owners resorting to debarking. Four veterinarians said then that they had seen "two to three yearly requests" in the past three years, where there was none before.

Ms Deirdre Moss of the SPCA said that debarking "takes away a dog's voice, their main form of communication", and that owners should go for training with their dogs to address excessive barking instead.

Dr Wong Hon Mun of the AVA said debarking, along with declawing of cats, should be the "final alternative, under very special circumstances and when it is necessary for the welfare of the animals concerned".

Sources: The Straits Times, My Paper, The New Paper, AVA, Humane Society Veterinary Medical Association, National Animal Interest Alliance, The New York Times, The Huffington Post, Australia's Victoria State Government, stopdevocalizationnow.org, Council of Europe Treaty Office