Capt. Ruben Saavedra says the 19-month-old boy's mother found him floating in the pool around 10 a.m. Sunday at their home near 35th Avenue and Ocotillo Road.
Saavedra says she immediately administered CPR and the boy began to cry and vomit.
Firefighters took the boy to a hospital and no significant injuries were found.
The mother told firefighters that she believes the child slipped outside through a doggie door and a latch on the pool fence may have been opened.