A horse sanctuary in Maine is asking for donations to buy a new penis for a cancer-stricken pony which is close to death.

Richard, a 15-year-old Shetland mini cross, was brought to the Animal Rescue Unit in Palermo, Maine, in December by a horse dealer.

Staff immediately noticed a rotting smell coming from him and quickly located it to his sheath.

When worker Brogan Horton touched it, the frozen tip fell off, leaving him with a swollen appendage with leaking holes all over it.

Vets from Third Coast Equine have since told staff that the pony's penis is plagued with cancer.

Richard the Shetland mini-cross needs a new penis because his is infected, wounded and leaking due to a painful cancer

They suspect it was left untreated by his previous owners for years and that this is why he is now in such a grave state.

Sanctuary workers appealed for donations to raise the $4,000 they need to pay for Richard to undergo a surgery to have his infected penis removed and replaced.

He also needs to spend time indoors, out of the bitter winter cold, to recover properly, they say.

Horton is asking kind well-wishers to make donations on a YouCaring page found here.

They reached their $4,000 target on Tuesday afternoon.

She said she was stunned when she realized how serious Richard's condition was because he himself barely flinches when his wounded penis is touched.

'The night he arrived, a 2x2 chunk of his penis flesh,broke off.

'It has rotten so badly that it has destroyed the flesh and created additional holes,' Horton said in a description on the fundraising page.

Richard's penis is bright red and swollen with holes all over it. Despite his agonizing condition, staff say he lets them treat him and is a 'trooper'

Staff at the horse sanctuary want to raise $4,000 to pay for Richard to undergo surgery and still have enough money to pay for his care costs afterwards. Because of the brutal temperatures in Maine, they want to ensure he will be able to recover indoors

On the night he was brought to the sanctuary, it was -25 and Richard did not have a coat

She said the sanctuary would not normally spend so much money on a surgery for an animal if it was older, but that Richard deserves a chance to live 'pain-free'.

'He's only mid teens and deserves to live life pain free for the second half of his life,' she said.

Despite what looks like agonizing pain, Horton said Richard shows no signs of suffering or acting out.

'I can't fathom what he suffered.

'He's on a lot of pain meds right now but I'm sure it was excruciating before.

'Richard deserves a medal of patience. He's full of life but is very, very good about letting us treat him.

'I think he understands we're here to help,' she told DailyMail.com.