This study evaluated a polylactic and polyglycolic acid (PLA/PGA) implant as a partial tracheal substitute in young developing canines. This experimental and longitudinal study included local stray pups that received substitution of a short cervical tracheal segment with a PLA 85%/PGA 15% plaque. We measured clinical, endoscopic and tomographic variables for 1 year, at which time we performed histomorphological evaluations of the implant using light and electron microscopy. There were no adverse events throughout the clinical progression. On endoscopic evaluation, the implant was covered with mucosal tissue beginning in the first month, without granulation or stenosis, and the circular shape of the trachea was altered. Tomographic images of the tracheal area at the implant site were similar to adjacent healthy areas (p=0.423). At the end of the follow-up period, the plaque had biodegraded, and the space was covered by pseudostratified epithelium and ciliated cells similar to the neighboring tissue. Implantation of a PLA/PGA plaque constituted an effective (functional) replacement of a short semicircular cervical tracheal segment without limiting the growth of the recipient. Additional studies are required to prove the efficacy of these implants for larger tracheal segment replacements and in subjects at different stages of development.