Shocking images, which appeared on the North West SPCA Ballina Facebook page, show the body of a dog which was recovered from the River Moy in Ballina.
Animal rights group ARAN say they are responding to a deluge of calls from outraged members of the public in response to the horrific case of cruelty.
"As a result of this latest case of cruelty, the group is offering a reward of up to €1500 for information leading to the arrest and conviction of the person or persons responsible", Aran said.
The animal, which is believed to be a one-year-old lab/collie mix, had been tied at the neck to a concrete cinder block and drowned.
The North West SPCA said: "When we got there, this is what we found, the remains of a poor young lab/colliex male that had been tied to a concrete block and thrown into the river."
“It is imperative that any community faced with a violent act such as this take measures to find the culprit or culprits responsible and bring them to justice,” says ARAN’s John Carmody.
“Animal abusers are a danger to everyone – they take their issues out on whomever is available to them, human or non-human, and must be apprehended before they act again, which is why we hope this reward from ARAN of €1500 will get people picking up the phone to give us or the authorities the information needed to cage the monsters.”
The group added that "past incidents involving cruelty to animals regularly appear in the records of serial rapists and murderers.#2
"This was so difficult to witness, the suffering of the dog would have been unbearable", read the SPCA's Facebook post. "The cruelty involved in this is unspeakable."
If you have any information about this brutal act of cruelty please contact Ballina garda station on 096 21422 or 1800 666 111 for the garda confidential line.