SINGAPORE - A government veterinarian who checked on a horse at a Gallop Stable's Pasir Ris ranch three years ago saw it drink water non-stop for two minutes and eat continuously for up to half an hour - something she had not seen before.

The thoroughbred mare's right hind leg was also severely swollen and infected, and it had flies in its eyes.

The next day, another vet who saw the horse taught stable staff how to wash its wounds twice a day.

But three days later, she had to use forceps to remove maggots which had burrowed deep into a wound - something that would not have happened had her instructions been followed.

These details emerged on the first two days of Gallop Stable's trial at the State Courts for animal cruelty on Monday and Tuesday (May 10 and 11). The company, which owns three ranches here and one across the Causeway, is denying its single charge.

A district court heard that Dr Wendy Toh was at the Pasir Ris ranch on May 15, 2013 for an unrelated visit when she saw the horse, named Sharpy, lying down. It was bobbing its head in a bid to get rid of flies in its eyes.

Its right hind leg was about three times the size of a normal leg and it looked to be in obvious pain. And there was also faeces in the background.

"I really feel sorry for the horse," said Dr Toh, who was then with the Agri-Food and Veterinary Authority.

When water was taken to it, the horse used its mouth to suck the liquid up, instead of using its tongue to lick the water like normal horses would. It also ate up the hay that was given to it.

The next morning, another vet went to check on the horse after being called by Gallop Stable's director.

Dr Phyllis Yew, who is in private practice, found it lying down, with a fever. There were numerous sores covering about 85 per cent of its right hind leg, which was very swollen and filled with pus.

In some areas, the skin had actually peeled away, leaving open sores. The sores would have developed up to eight days prior to her visit, said Dr Yew.

The horse also had conjunctivitis in its eyes and its eyelids were swollen. There were also several wounds on its face as the horse had been scrapping and banging its head against the ground in a bid to get up on its weak legs.

Dr Yew prescribed intravenous antibiotics and painkillers and showed the stable staff how to clean the animal's wounds. She also instructed them not to let the horse lie down to prevent further injuries, such as nerve damage.

But when she returned three days later, she had to use forceps to dig out maggots which had burrowed deep into a wound on the horse's right elbow.

This would not have happened if the staff had cleaned the horse's wounds twice a day, as instructed, with an antibacterial wash, said Dr Yew.

The cleaning technique is simple and not complicated, she added. "It's a very simple wiping with an antibacterial wash."

The horse, now aged 20, is still with Gallop Stable. If convicted of failing to provide adequate veterinary attention to its horse, thus causing unnecessary suffering to the thoroughbred, the company faces a maximum fine of $10,000.