1980, Paul A. Hutton, The Cowboy Hero review, Utah Historical Quarterly, Volume 48, Number 3, Summer 1980, pages 321-322:
“Cowboyitis” strikes down men and women of all ages, educational backgrounds, and professions. The stockbroker, insurance agent, and college professor are as likely to be victims as the truckdriver, construction worker, or cab driver. This social disease is epidemic both east and west of the Rocky Mountains and the telltale symptoms are are well known. The stricken soul comes home from a hard day at work and slips into his faded Levis (preferably a size or two too small) and shiny Tony Lama boots. With an oversized Stetson daringly tilted back on his head he settles into an overstuffed easy chair, lights up a Marlboro, flips open a tall can of Coors, and watches the Denver Broncos brutalize some hapless opponent on the television.
1999, Mark Zeligman, George Brett: A Royal Hero, page 59:
He owns a horse, a Morgan filly named Funquest Siri, and soon he'll own a ranch near Kansas City (he won't say where). Moreover, Brett has the chafed fanny and blistered memories of riding a real roundup back to his claim.
It's not unreasonable to credit some of Brett's cowboyitis for his more relaxed personality since the baseball strike ended.
1986, Robert G. Athearn, The Mythic West in Twentieth-Century America, page 58:
He savored the term frontier and asserted that to the genuine American it was "the dearest word in all the world." He was another of those who stressed the notion that authentic Americanism was largely a frontier product, albeit a characteristic that had been diluted, as Hough put it, "by far less worthy strains," but one, he hoped, that still showed some signs of strength in the West.
For those who eschewed the printed word, there was Theodore Roosevelt, a converted easterner who was afflicted by a terminal case of cowboyitis, who now railed at authorities for their refusal to let him charge up Teutonic San Juan hills and corral the kaiser.
2016, Slim Randles, "Home Country", Freestone County Times, 23 November 2016, page 2-D:
On a morning like this, his daily dose of "cowboyitis" lets itself be felt. That aching hip? Oh, he remembers when that colt dumped him into the rockpile, putting him on crutches for two months.
Noun: "an infatuation with or attraction to cowboys"
2002, Jennie Marie Leis, Life, Love, and Cowboys, page 32:
Cowboyitis starts as just an innocent crush but soon it progresses so that the minute you see a cowboy hat your pulse quickens and you immediately focus on the form beneath it.