Thugs tied firecrackers to the testicles of a dog and set them alight before a car mowed the poor pooch down.
Demetrio, who had been roaming the streets for many weeks, was discovered on the Caribbean island of Puerto Rico.
The animal rights organization Rabito Kontento (Happy Little Tail) rescued him a few days ago and is now fighting for his life.
Vets said Demetrio suffered from a scrotum necrotic infection, which resulted in it being full of worms.
Sharon Deliz, the spokeswoman for Rabito Kontento, told El Vocero newspaper that his wounds indicated firecrackers were bound to his testicles and lit up.
She added that Demetrio, having been run over, could not pass.
Heartworm, a parasitic roundworm that can cause serious lung disease, heart failure, and other organ damage, has also been identified.
Deliz said they have not yet reported the incident to the police because no perpetrators were seen by the people who found the puppy.
She added: “That a person could do such a thing is horrible.” It was because Demetrio probably approached them for food or affection if someone did that to him and got close enough that they could catch it and tie the firecrackers to their genitals.
He was humiliated and hurt for being a good pooch. He experienced unimaginable pain because he was a good dog.
The group is also raising money for the ongoing care of Demetrio.
donations can be made here.