Police are appealing for information to try and catch the person who beat a dog so badly that it may have suffered brain damage.
The attack on the terrier cross-breed, named Holly by her carers, happened on November 30 at 3pm in Cefn Fforest.
A passer-by stepped in to help the dog and stopped the attack.
Holly, as she was later named, was taken to the Bridge Veterinary Surgery in Pontllanfraith, for treatment.
Vet Graham Blow said: “When she came to us she had some of the worst injuries I have ever seen in a dog.
“Her lower jaw was shattered, she had three broken ribs, serious concussion, and severe swelling in the left side of her abdomen.
“I have every reason to suppose that if this bloke isn’t dealt with… he’ll go on to harm other animals and probably people too.”
The passer-by who intervened was verbally and physically threatened by the dog’s attacker but they eventually stopped the beating with the attacker running off.
The witness described him as about 6ft 3in, slim to average build, in his twenties, with fair, light brown or dark blond hair. He had a local accent.
Holly was released by vets this week and is now being cared for by a foster family found through Caerphilly County Borough Council’s dog warden.
There are fears there may be difficulty in re-homing her because of her wariness around men and the possibility she may have suffered brain damage.
A Gwent Police spokesperson said: “We understand that people may be afraid to identify this dangerous person, but they can provide us with any information they may have anonymously through the 101 non-emergency police line, or via Crimestoppers on 0800 555111.”