Perez was arrested after he and a group took a tour of the Chicago Animal Care and Control Facility at 2741 S. Western Ave. on May 29, prosecutors said.
After the man broke off from the tour group, an employee of the facility spotted him going into a restricted area, prosecutors said. After the employee told the man to leave the restricted area, the man left but returned a short time later.
When the employee returned, he found the man inside the restricted area again and inside a cage with a white and grey pit bull, prosecutors said.
The employee found the man on his hands and knees on the side of the dog, and it appeared the man had just had sexual contact with the animal, prosecutors said.
The man made "inculpatory statements regarding sexual conduct with the dog" to several employees of the facility, police said.
After the man gave his license to a security guard at the facility, the police arrested him at his home on Friday, police said. The burglary charge involved his being in the restricted area of the facility, according to court officials.
His bail was set at $80,000.