We meet chihuahua Chloe, setting up residence in an east London nail salon. She arrives and immediately wants to befriend ten-year-old Rocky, formerly top dog in the household, but Rocky is not interested. With the two dogs fighting constantly, Louise is called in to help restore the peace. Border collie Jura joins a ski patroller in the Highlands of Scotland, where owner Will wants to train her to become the Nevis range's first avalanche search and rescue dog. Rescue pup Pedro is brought from Spain to spend his life in the genteel surroundings of the Surrey countryside with Rick and Sarah in Shalford, as Rick enters semi-retirement. But when Pedro escapes from his cage in the middle of the night, Rick's relaxing retirement becomes a DIY nightmare as he attempts to secure the house and garden, and keep his new friend safe. And golden retriever Lola joins the Paye family, where mum and dad have been persuaded to get a dog by their children, on the agreement that they will do all the hard work. But mum Claire is quickly left to do all the training. As Lola displays a very stubborn streak, it becomes a battle of wills - Claire v Lola.
—BBC's Official Plot Summary