After a long, cold winter, the animals of Isabella County are getting testy. Dr. Pol and Charles head out on a farm call to treat an angry bull with a deadly case of bloat. Dr. Pol must act quickly, or the bloat could block the bull's diaphragm and lead to death. Back at the clinic, a cat injured while birthing kittens inspires Charles to volunteer at HATS, the Humane Animal Treatment Society, whose goal is to keep the animal population in check by way of spaying and neutering animals.

After successfully handling a cow with a twisted stomach, a rabbit with overgrown teeth and a complicated foal delivery, Dr. and Mrs. Pol head off to their much needed vacation. Taking care of his patients is Dr. Brenda, who tends to Debo, a rambunctious escape artist dog who has broken his foot in four places. She also aids a cow that may have slipped on ice and a cat with a toy in its intestines. Eager to help, Charles goes on a farm call with Dr. Brenda to check on a baby goat with pneumonia.

As winter drags on Charles, Dr. Pol and the rest of clinic staff brave the frigid temperatures to keep animals healthy in the clinic and on the farm. The first stop is an organic farm where the owner recently lost two calves to a mysterious infection. Across town, Dr. Brenda is called out to visit a 10-month-old horse who has cut his leg badly on a rusty trailer. Later, Dr. Pol and Charles investigate two bizarre cases, both involving birth defects at the opposite ends of two young calves!

It is birthing season in Michigan, which means Dr. Pol and his clinic staff have their hands full. After receiving an emergency calving call, Dr. Pol and Charles discover that a heifer is already in labor -- but is still out in the pasture. So before he can help her, they'll have to catch her! Meanwhile, Dr. Brenda gets an urgent call about a few sick piglets that were recently purchased for a 4-H project, and she must stop this potential pneumonia epidemic before it spreads even further.

Roses are red, violets are blue, when animals go crazy, Dr. Pol knows what to do. For Dr. Pol, Valentine's Day means flipping a cow upside down to fix his stomach, de-worming a champion goose, and curing the relentless cough of Zev, the Siberian Huskie. Now, that's love. Inspired by Zev the huskie, Charles takes a shot at driving a sled dog team, but realizes that mushing isn't as easy as it seems. Meanwhile, Dr. Brenda dehorns a group of loud, but loveable pygmy goat babies.

Dr. Pol challenges Charles to take part in the local Special Olympics charity event, the Polar Plunge, where participants dive into an icy lake in the height of winter.Then, Dr. Pol races to a farm call to check on a horse that's showing irregular symptoms. Meanwhile, Dr. Brenda discovers a cow is having respiratory issues and has twisted its stomach. Finally, Dr. Pol must race out on an emergency farm call to young racehorse who has severely wounded his leg, jeopardizing his racing career.