Rocky Mountain spotted fever (RMSF), a severe tick-borne illness, is not just a local health issue but a growing concern across the southwestern United States and northern Mexico. This disease, caused by the bacterium Rickettsia rickettsii, is transmitted by the brown dog tick and can lead to fatal outcomes if not treated promptly with antibiotics. The resurgence of RMSF highlights significant public health challenges, intertwining human and animal health and underscoring the need for a comprehensive One Health approach.