broncitis
A breathing-difficulty caused by saddle-breaking wild horses, either because you spend too much time at it, or because you're just not "cut out for it" physically.
Charlie Brown's intellectually-naive little sister Sally claimed that the Broncitis was a dinosaur that soon became extinct because it coughed a lot. Maybe what actually happened was that its lungs got totally worn out from wheezingly/lumberingly chasing after the speedy prehistoric wild horses who preferred not to become said dino's lunch.