When Lambie becomes jealous of Doc's new Valentine's Day toy, Doc diagnoses her with "splitheartitis" and reassures her that no one could ever take her place.
Recap[]
It's Valentine's Day as Doc gets a new Valentine's day toy, a heart-shaped character Doc named Val as the toys are having their Valentine's day party, Lambie feels sad and left out when the other toys started loving Val instead of her as Doc remembers all the love she gave to Lambie as it is up to Doc to cheer up her favorite cuddler, Lambie.
Season One:Ba-Ba Bubbles • Bop, Bop, Bop (Don't Wanna Pop) • Pop Up • Get Your Sleep On • Close Your Eyes • Be Safe • Water, Water • Everyone Gets Hurt Sometimes • Be Good to Your Tummy • Rockin' the Right Note • Nobody Wants a Broken Toy • Stars, Stars • We're Ben-Anna • You Can Do It • If You Got the Hiccups • Dig, Dig, Dig • When You Need a Friend • Do What the Doctor Says • Ready for Action • In a Flash • Rest Your Rotors, Ronda • Keep Still • Nobody's Perfect (Forgive and Forget) • Here For You • We Can Light the Night • Have You Heard • Blast in a Cast • Eat Good Food • Camping's Great • You're Gonna Grow • A Lambie Like You • My Better Half • The Things You Like • Tell The Doc • It's Your Birthday (Happy Birthday Hallie) • My Shark's Tale • Stick With Me • Because You're You • Everybody in the Pool • Loud, Loud Louie • Wash Your Hands • Clap, Clap, A-OK • Take Care • Made in the Shade • On Halloween • Let's Play Outside • Chillin' in the Snow • Look Great in Glasses • Shine • Blue Skies • Dinosaur Stomp • Brush Your Teeth Season Two:The Doc Mobile • No Matter What • I'm So Strong • Let the Good Times In • A Little Help • Twisted Tail Blues • Wing Deep • Stuffy the Great • Be You • Take Care of Yourself • A Little Sun • What Friends Do • Stay Calm • My Helmet • Keep On Dancin' • Room to Zoom • Why Does It Have to Be You? • Blow, Blow, Blow Your Nose • Your Body Feels Great (When It's In Shape) • Itchy • What's Better Than Toys? • A Very McStuffins Christmas Time • I Shake-a-My Hair • Beat the Heat • Picture You • Her Spots Are So Spot On • Hallie Hippo Happy Hour • Peachy Clean • The Rest is Up to You • Be a Patient Patient • The No-Tangle Tango • Stay Cool in an Emergency • A New Way to Be Wild • There's So Much to Adore About You • I Love My Hairdo • Hey, Star Blazer Zero • Weather the Storm • Fix It Now • Forever Friends • Three Cheers for Chilly • A Princess Can Too • Treat It Like a Treat • We're On the Same Team • Here We Go • Everyone (Look What I Can Do) • Don't Eat a Little Toy King • One Toy at a Time • Backyard Rules • Wash Your Face • He's a Monster • Be a Doctor Too • Don't Worry, We'll Wait • So Much to Say • Love What You Do • Before You Sleep • Fess Up • Ready to Serve • Look Before You Leap • Just Say Hi • Stop • Smiling's Good for You • Get the Spaces In Between • I Can't Cuddle • Bonk Your Noggin • Eyes on the Road • The Right Shoes • Get Your Eyes Checked Out • Give It a Try • Be Brave • Sunscreen • The Show Doesn't Have to Go On • Your Animal Friends • Directing Melinda (In a Ballet in a Pool) Season Three:Teddy B Blues • Walk, Don't Run • Brave Queen Bessie • Step Out • Wait for It • Chew Your Food • It Was Only a Dream • Suddenly Somebody Else • A Toy to Love • I Want to Adopt You • Get Ready • Pick Me • Everyday • She's the Boss • Even the Brave • Pop, Pop, Pop (Did I Getcha?) • School Is Awesome • Glitter Can Happen • The First Lady and Me • Breathe Easy • Safe 'N Spooky Time • Sad Stuck Gator • The Magic Is Me • I'll Wait for You • Squibbles, Come Home • One of a Kind • Out of Sight • Queen of Ballet • My Style • Out with the Old • Talk to Kids • Use Your Imagination • Not Cool to Get Too Cold • Take a Break for the Team • A Part of Me • What's Best for Your Pet • Trophy of Dreams • Can't Stop the Giggles • The Unknown • Bust a Marvelous Move • The Best Big Sister • The Giving Is Good • Green As a Four Leaf Clover • Any Size at All • Plenty of Love (to Go Around) • Bike Rules • Babies are the Best • No Longer King • The Baby's Comin' • The Things We Can Do • Love That Little Baby • Home • Suited Up for Safety • Focus • New Haircut • Slow Down, Sleep Now • I'm Gonna Win • Putting the Awe in Awesome Season Four:Welcome to the Hospital • King of the Broken Toys • Never Stop Loving a Toy • So Proud to Be Med Students •I Know What's Best • Get Psyched to Work All Night • There's an Appointment for That • Your Signature Style • Ride, Ride the Ambulance • Without You • Stay on the Line • Baby Bathtime • Help Us Help You • Too Far • Rest Your Voice • The Big Foosball Game • Making a Diagnosis • Stuck Here Blues • The Emergency Room • Buddy Up • Bye Bye Bouncy Boo-Boos • Therapy Pet • It Matters What You Say, Mr. Mayor • A Monster! • Safely Across the Street • Get You to the Party On Time • Where You Should Be • Get a Better Picture of You • Follow That Bear! • Think Heavy Thoughts • Me and My Guide • Think Like Your Pets Think • Make You Better • Doc's Gonna Figure It Out • Brave Like You • If You Wanna Say Hi • I'm So Great at My Job • Better Bedtime Steps • Not the Bedtime Blues • Not for Touching • Ready for You • Oh No! We're Baby Toys • In Case of an Emergency • Who Needs a Doc When You've Got a Duck • The Hero Inside • First Responders Respond! • We'll Put It Back Together •What a Mermaid Can Do • Hula No More • Make the Right Call • Just Bring You • Meant to Be Wild • Tonight is Going to Be Perfect • A McStuffinsville for All • Remember Your Numbers Season Five:We're the Pet Rescue Team • The Best Rescuer Ever • Your Perfect Pet • Where'd He Go? • Christmas Is Coming • Christmas Miracle • Rescue in Space • Rocket to the Rescue • The Search for Cece • A Kid Always Knows • When I Get to Dragon Mountain • Love Makes a Family • Good to Be Good • Ask Anything • Helping Toys Is What I Do • You Can Depend on Your Friends • Mumbo and Me • Time to Let You Go • This Could Be My Life • You're Our Star • Lost Toy Lament • Going Home • Everything Bling • Jungle Quest • You Shine • Replaceable • When There's No Snow • Best Medicine • A World Without Doc • Water Wing