Video shows one male picking up the dog, named Buddy, while another puts the keg tap into the dog's mouth and pours, with laughter and cheering around them.
Buddy is now in the care of the Nassau County SPCA.
Detective Matt Roper says Buddy was in good condition when they tracked him down. Roper says the dog's owner is a Hofstra senior and member of the Alpha Epsilon Pi fraternity. The owner, Roper says, promised investigators he would immediately take the 8-month-old pup to a veterinarian for a check-up.
But Roper says the owner didn't do that, and they had to take Buddy to get immediate care.
Neighbors of the frat house say they were appalled by the video. No one answered the door at the frat house Tuesday.
Roper says the SPCA has received upward of 100 phone calls from people looking to adopt Buddy, who's a Cavalier King Charles spaniel. But Roper says Buddy is still evidence in the ongoing investigation and cannot be adopted until the case is closed.
No charges have been filed at this point.