In The Lord God Made Them All, country veterinarian James Herriot shares stories of his veterinarian practice in post World War II England. Among his stories Herriot writes of his personal experiences with the many advances in veterinary medicine during this time, his adventures with travel as a veterinary attendant, and the love of his growing family. Through all of his trials and adventures, Herriot includes the warm humor and positive outlook that makes his writing joyful and victorious.

While Herriot's book is largely a collection of unrelated story of his life and work, Herriot scatters throughout his writing entries from a journal he kept during a trip to Russia and a trip to Istanbul. Although they are not included consecutively, these chronological journal entries serve as a backbone for the entire book. These two trips are perhaps Herriot's greatest adventures while serving as a veterinarian. In his first trip Herriot serves a veterinarian for a flock of sheep headed by boat to Russia. This trip is made in gale force winds and stormy seas. In his second trip, Herriot heads to Istanbul with forty head of cattle. This adventure takes place in a dilapidated airplane in which one of the engines actually catches on fire during the trip. While each of these trips could have easily been considered disastrous, Herriot presents them in his signature outlook of joy and adventure.

While he enjoys the adventure of his trips, Herriot's writing shows that his favorite place is his home town of Darrowby, England. It is here that he shares a thriving country practice with another veterinarian, Siegfried Farnon. Herriot enjoys the English countryside as he travels from farm to farm, often with his children, tending to the veterinary needs of various farm animals.

Along with his memories of his developing veterinary practice and the many developments made in the field of veterinary medicine, Herriot shares stories of his everyday life. He writes of the birth of his daughter, the help he receives from both his children when making his rounds, and his overwhelming pride in his children. Most of all Herriot shares through his writing the joy that comes from being able to perform a job that he loves.