Joseph Scaglione said that the animal had bitten him on the hands, ripping the nail off of his little finger during the incident in Jupiter, which lasted for “several minutes”.
The otter was later picked up by the Palm Beach County Animal Care and Control and tested at the Florida Department of Health Laboratory, which confirmed it was positive for the rabies.
Mr Scaglione told local news outlet WPTV that he had been attacked while feeding ducks at a pond near his home on Saturday.
“I went through our back gate and I was just going to close the gate and then that would have been it, but as I started closing the gate it charged (and) immediately attacked my legs,” he said.
“I started to push it away and it started to bite my hands. One of the bites that I have is on my pinky and it actually ripped the nail off the pinky.
“It looks like the tooth went completely through my finger.”
Mr Scaglione said he has received several shots for rabies and would be visiting a surgeon in the coming days to assess the damage to his hands.
Following the attack a neighbour was able to trap the otter using an upturned recycling bin before Animal Care and Control arrived, according to WPTV.
In a statement, The Florida Department of Health said: “Animal Care and Control confirmed on September 23rd that a rabid otter bit a dog and then a person in the 900 Block of Marlin Drive in Jupiter, FL.
“The otter was picked up by Animal Care and Control and then sent for rabies testing.
“Residents in the area are cautioned to avoid contact with any wildlife including feral/ community cats and report suspicious animals to Animal Care and Control.”
Rabies is a disease of the nervous system and is fatal to warm blooded animals and humans if not treated.
The only treatment for human exposure to rabies is rabies-specific immune globulin and rabies immunisation, and appropriate treatment must be started as soon as possible after the exposure to protect an exposed person from the disease.