Along with others including Vincent Fago, Jim Mooney, Mike Sekowsky, and future Mad magazine cartoonists Dave Berg and Al Jaffee, Hart worked on such movie tie-in and original talking animal comics as Terrytoons Comics, Animated Funny Comic-Tunes and Mighty Mouse.
"[9] Hart freelanced in the 1950s for that decade's Marvel predecessor, Atlas Comics, and also wrote for detective and true-crime magazines, occasionally being recruited to pose as a character on a photo-cover.
[2] Hart also began freelance editing, illustrating, and ghostwriting for Herbert Axelrod's newly formed TFH Publications, helping produce its technical books for pet owners, and eventually joined its staff and became editor-in-chief.
He drew cover art for Alan Kirk's TFH book on Scottish terriers and Allan Easton's on Shih Tzus.
[10] Hart, occasionally signing his work "EHH", also did stories for Charlton Comics, including writing and drawing issues of the horse series Rocky Lane's Black Jack in the late 1950s.
When Lance was 9 years old, in the early 1950s, the family moved to Orange, Connecticut, where they built a house near a veterinary clinic run by Hart's longtime friend Leon Whitney.
Partly through this connection, Hart and his son Allan eventually became beagle breeders whose dogs included the bench champion Lynnlann's Button Up.
[3] While living in Florida, Hart painted and donated a 25-foot oil-on-canvas mural to the New Haven Central Hospital for Veterinary Medicine, depicting "the dog's place alongside man throughout the development of civilization.