The Labrador Retriever, named Pier by rescuers and thought to be one to two years old, was discovered with second and third degree burns over half of his body.
Large sections of fur and skin on Pier's face and body were completely burned off with parts of both ears, an eye and one of his legs irreparably scolded.
He was unable to bark or make a noise due to the severity of his condition but was luckily discovered by an animal control officer near Hobby Airport in Houston and rushed to the Scout's Honor rescue shelter.
Co-director of Scout's Honor, Leslie Hillendahl, said: 'This is probably one of the most difficult rescues we have done, emotionally and financially.
'We've seen a lot of bad stuff; this is hands-down the worst. If you ever met the dog, he's so friendly, so nice, all he wants to do is come up and nuzzle you. I can't imagine why anyone would want to do something to a dog like that,' she added to Channel 2 Houston.
Pier was discovered on February 20 - which vets believe was around a week after the attack.
Grey patches of burnt fur and pink patches of exposed skin covered the black Labrador's body and face including his heavily injured nose and back leg.
Shelter volunteers were unsure he'd survive but immediately took him to the Texas A&M Small Animal Hospital where he is still being treated.
'He'd been out about five to seven days with open wounds and burns,' Brian Hillendahl of Scout’s Honor told the broadcaster.
'Texas A&M told us they thought it was a miracle that he didn't have any infections even though he'd been out on the street for a week in that condition.'
Volunteers at the center were heartbroken by Pier's case and decided to launch a campaign to raise funds for his treatment.
Since posting the pictures on Facebook they have been astounded by the response - with thousands of people from across the world writing to express their horror and offer their support for the pup.
Donations have flooded in and a t-shirt has even been designed to help raise much-needed funds for Pier and other abuse cases.
One donor Melissa Petersen Listul said: 'A piece of my soul died when I saw what this sweet soul has had to endure. Thank you to all those that rescued him and got him to where he needs to be.'
Amanda Honeywell added: 'I hope the sociopaths responsible for this are caught and dealt with to the fullest extent of the law which probably isn't enough'.
Dawn Evans said: 'I am enraged at the silence of the people - that know about who did this.'
Houston police agree the attack on Pier is a horrendous case of animal cruelty but say they have little hope of catching the culprits unless someone with information comes forward.
An officer told Mail Online: 'We don't have an active investigation. It is very hard to track down any information because he was found as a stray.'
In the meantime, Pier is making huge strides forward in his recovery at a safe distance from his abusers.
Initially vets thought one of his legs was so badly burned it would need to be amputated along with damaged parts of his ears but they have been able to save it.
He also has sight in both eyes despite one being burned and ulcerated in the attack.
And bandaged pictures of the recovering pooch have however brought some relief to his rescuers and supporters.
Two weeks on he is now able to eat and move - and has even shown some interest in playing with a tennis ball.
Vets say he is expected to find his bark again later this month.
Although he will never fully recover - his burns are so bad he will have to have his back permanently covered - they hope he will soon begin a new happier life with a foster family.
Yesterday he was put under anesthetic to change all his bandages and have a tooth also broken in the attack.
'He is one strong boy and looks like he is going to keep fighting on,' a volunteer at the shelter said.
(Daily Mail - March 7, 2013)
