Sabuesos (2009)

The simple search for a lost dog turns into something much larger for a detective who learned his trade through a mail order course, and the sad sack uncle who agrees to become his sidekick. After mastering the art of sleuthing courtesy of the postal system, Anibal decides to move back to his hometown and put his newfound detective skills to the ultimate test. Before long, Anibal has established a detective agency with the help of his lonely, retired uncle, and the pair is paying a visit to the local police chief in search of a case. The chief assigns them the case of "Cachito," a small dog that has vanished without a trace. At first the search for Cachito seemed simple, but before long Anibal and his uncle will learn that sometimes it's the smallest cases that lead to the greatest discoveries.