The appalling case led to renewed calls from an animal welfare group last night for tougher sentencing for those convicted of animal cruelty.

Thor, a one-year-old Jack Russell, is recovering slowly from his injuries after being rescued by a couple who found him wandering on a road in Innishannon, Co Cork.

He had a laceration on the top of his head which stretched down the back of his neck, ligature marks around both rear legs, bite marks on his rear right leg, and a huge wound torn open to reveal a broken bone and joint in his rear left leg.

It is feared he may have had the wounds and been in excruciating pain for almost a week before he was found covered in fleas and emaciated.

His broken leg is so badly injured and infected that it will probably have to be amputated today.

He was brought to the Riverview Veterinary Clinic in Ballincollig for treatment, where vets believe his injuries are consistent with him being used as bait in a dog fight.

The injuries, they believe, were caused when the dog was tied by his hind legs and dangled to be mauled by a larger dog, or dogs.

It is believed the injuries did not occur in a single incident, leading to fears he may have been subjected to this form of appalling cruelty over a sustained period.

Valerie Mohally, a veterinary nurse, said it was one of the most appalling cases of suspected animal cruelty she had encountered.

“I couldn’t believe it when I came in and saw him. He was in a wicked way,” she said.

“But as we were treating him, the vet said sometimes it just doesn’t surprise her anymore when cases like this come in. And I knew what she meant. And that is sad.

“It’s absolutely horrific that this can happen.

“This is a living animal with feelings and emotions, and for anyone to think that this was right is absolutely sickening.”

Thor, named after the Norse god for his strength, has undergone several procedures to remove infected flesh and is on high doses of morphine for the pain.

This is Thor. He was used as bait in a dog fight. Highlighting his plight in tomorrow's @irishexaminer #Cork pic.twitter.com/XK8Jt23SFU — Eoin English (@EoinBearla) April 1, 2014

He is showing signs of improvement and has begun to eat. But he faces weeks, possibly months, of intense medical treatment.

The Dog Action Welfare Group, which highlighted Thor’s plight, said he has a long journey ahead of him.

“Sometimes in rescue, it seems like we are beyond shocking, our hearts are so fragmented as we witness more and more neglect, abuse, and indifference,” spokesperson Margaret Twohig said.

“It is difficult to understand how human beings can cause so much suffering on those who depend on us for their very existence.

“But irrespective of how many broken and battered dogs come to us to make their lives whole again we are never failed to be touched at how they react to human kindness — they bear no grudges.”

She said the sheer number of animals being abandoned, dumped, and coming into rescue centres across the country is overwhelming and she called for tougher animal cruelty laws.