Plot: Noel Fitzpatrick offers cutting-edge treatment for Luca, a long-suffering four-year-old springer spaniel with a painful elbow disease. He designs and creates a special screw for Luca's leg with a system for injecting a bone-growth gel around it, and after an eight-year-old Newfoundland collapses, its owners face an agonising wait for the MRI scans to reveal if anything can be done for the gentle giant