The dogs are in a high-risk situation

The dog in the picture doesn't just look abused, but also neglected, said Action for Singapore Dogs president Ricky Yeo.

"You can't leave the dog confined near the window as it can get heatstroke," he said.

He added that it amounted to abuse since the dog is "constrained and defenceless".

"If this treatment continues, it can become aggressive. If the dog is mild, it will tolerate the beatings. If it is aggressive, it may one day bite the owner," he added.

The dogs are also in a high-risk situation, Mr Yeo said.

"In a worst-case scenario, the father may pick up a dog in a fit of rage and throw it down. It has happened before."

It was good that the son had gone to the authorities, though Mr Yeo thinks the father would be let off with just a warning.

Nevertheless, the son's role has been crucial in ensuring the abuse stops. He suggested the son keep the dogs away from his father when he's not at home.

The son could also get a professional dog trainer to explain to the father how to control the dogs without abusing them, Mr Yeo said.