Complex sentence: The affected chihuahuah will hold its leg flexed, and foot off the ground until the quadriceps muscle relaxes and lengthens, after which the animal feels no discomfort and continues with activity.
Split into simpler sentences: The affected chihuahuah will hold its leg flexed, and foot off the ground until the quadriceps muscle relaxes and lengthens. Once out of position, the animal feels no discomfort and continues with activity.