The male black-and-white cat was found in the lagoon on Wednesday with a five-pound dumbbell tied around its neck. It was discovered by Redwood City public works employees, who brought it to the humane society, shelter spokesman Scott Delucchi said.
The dumbbell was attached to the cat's neck with zip ties, he said.
The cat appeared to be middle-aged and his front paws were declawed, indicating that he was likely someone's pet and not a feral cat, Delucchi said.
The nature of the crime indicates clear intent to harm the animal, which is a felony, he said.
Thursday the humane society announced it was offering a $1,000 reward for information leading to the arrest and conviction of those responsible for the crime. That award has since grown to $8,400 after individuals and two businesses pledged donations for the reward.
According to the PHS, the owner of the Swingin' Door in San Mateo pledged $1,000 and Pet Food Express contributed $2,750.
A humane society veterinarian conducted a necropsy Friday that revealed the cat was alive when it was dumped in the lagoon with the weight around its neck, according to the humane society.
"We continue to believe this was an owned cat and that someone intentionally killed him in a horrific, unimaginable way," Delucchi said today. "We need the public's help in order to find the owner and the person responsible."
The cat did not have a collar or an identification microchip.
Anyone with information about the crime is urged to call the Peninsula Humane Society at (650) 340-8200 or email at email@example.com.