The flu takes the clinic by storm, but Dr. Pol and his staff must fight through it. Dr. Brenda struggles to find out what is causing a dog to be so abnormally lethargic. She learns from his owner that it's possible he was exposed to marijuana. Dr. Brenda is relieved that the dog will be back to normal in a day. Then an entire herd of cows are too thin despite being well fed. Dr. Pol thinks it's a lack of minerals, and is surprised to find the entire herd has come down with pneumonia.

It's time for the Isabella County Fair, which culminates in the 4-H competition. Dr. Pol and his staff are busy tending to animals that need last minute checkups to make them eligible to compete. Dr. Pol, Charles and Dr. Sandra bounce back and forth between the fair and farm calls, while Dr. Brenda holds down the fort at the clinic to deliver a set of bulldog puppies. When Dr. Pol and Charles get in to a bidding war over a sheep at the fair, it's anybody's guess as to who will come out on top.