距离第二部后猫狗休战已经过去10年了，猫狗两家共同发明了一种监控系统，维持和平化解冲突。然而当一只精通技术的鹦鹉出现，利用自己的“黑客”技术入侵，并使用猫和狗才能听到的频率来操控它们，世界各地再度爆发猫狗大战！于是，一群没有经验的新手猫狗特工要用最原始的方式来恢复和平。

　　It's summer again, and everyone's favorite Junior Rescuers, The Flounders, are back at Tower 2. With the International Junior Rescue Championships headed to Southern California, the eyes of the entire planet are on Malibu Beach. But when Team USA falls victim to a bout of food poisoning, it's up to Tyler, Dylan, Eric, Lizzie and Gina to represent their country in the world's most extreme lifeguard challenge.