Dynamic obstructions of the equine respiratory tract are often underdiagnosed or misdiagnosed with resting endoscopy. So veterinarians usually perform endoscopy on exercising horses using treadmills, in order to try to reproduce the exercise conditions. However, treadmills are only available in limited places and facilities. At the 2008 American Association of Equine Practitioners convention, held Dec. 6-10 in San Diego, Calif., Youssef Tamzali, DVM, PhD, Dipl. ECEIM, of the Ecole Veterinarie de Toulouse in France, described a two-year collaborative effort between engineers and clinicians that resulted in an endoscope that can be used on horses exercising under natural conditions.