Young Saint Bernard Harley sees Dr. Debbie James when her legs begin to fail; kitten Loki is found to have a heart murmur during a routine vaccination, and Dr. Regan Williams suspects a congenital heart defect but does an ultrasound to learn more.

At the local zoo, Pinky the cheetah needs Dr. Sharon French's help to fix a broken tooth; Dr. Jon Forbes treats poodle Mocha after an unfortunate encounter with a larger dog; golden retriever Shadow seeks help from Dr. Regan Williams for heartworm.

Dr. Devon Boyd's own large pup, Sarge, needs TPLO surgery to repair an ACL tear in his knee; Pomeranian Rosie sees Dr. Sharon French for a long-overdue teeth cleaning under anesthesia; Lulu the bulldog has mysterious neurological issues.