The dog's ribs and hip bones were visible and she scored a 4.5 on a conditioning test on a scale where 1 is ideal and 5 is emaciated, the report said.
Athena's white paws and chest were discolored yellow, apparently after being soaked in urine.
"The most basic of care was not received by this dog," wrote Dr. Kristen Coates, a staff veterinarian for Palm Beach County Animal Care and Control.
Perez told officers that the dog suffered from separation anxiety and would not eat when he left for work, the report said.
After Perez turned over custody of the dog to Animal Care and Control, it ate "voraciously" and gained 15 pounds in just over two weeks.
A records check showed that someone complained May 8 that Perez and his wife were keeping the dog inside a small crate all day and that the animal smelled of feces and urine.
The condition of the dog came to light after PBSO began investigating the death of Perez's 9-month-old on Sept. 25. The boy was found "unresponsive after sleeping with the parents," according to the Florida Department of Children and Families.