Carroll Howell was born in Holliday, Missouri. He earned a B.S. degree from the University of Missouri and an M.S. degree from the State College of Washington.
In 1917 he was appointed Assistant Professor of Animal Husbandry at the State College of Washington. He moved to the University of California at Davis in 1920 as Assistant Professor in the Animal Husbandry Department. He became a Professor in 1952 and retired in 1958. In addition to his work at UC Davis, he served as manager of the W.H. Kellogg Institute of Animal Husbandry at Pomona, California from 1939 to 1943.
While employed at UCD, Carroll Howell carried a heavy teaching load. From 1928 to 1939 he had most of the responsibility for non-degree instruction in Animal Husbandry. At various times he also taught each of the production courses offered by the department. He also assisted in coaching the judging team, advised students on curricular and extra-curricular activities, and managed the equine stud for the department.
Carroll was active in University service to the livestock industry. Often he was invited to speak at agricultural meetings and for many years was chairman of the departmental committee charged with presenting research results to the livestock industry. While managing the Arabian Stud at Pomona he served the University with distinction; stimulating research on horses and using the facilities and horses for public relations in the Los Angeles area.
He was a highly regarded judge of livestock and horses, both draft and light. He served as an official judge at many fairs. He was a member of the advisory board for the California State Department of Fairs and Expositions.