Dr. Mike Dix and Jeff Popowich visit a Navajo community in Arizona to help with a canine population crisis. Meanwhile, a Lab mix with a mysterious condition arrives at DogTown; and Pat Whitacre trains another Lab mix that compulsively digs holes.
Jeff and Michelle take part in a large-scale puppy-mill rescue in Missouri. Meanwhile, Ann tries to teach a German shepherd to dance, hoping the advanced obedience-training method will improve his behavioral issues.
Sherry Woodard trains shelter dogs in search and rescue; Dr. Mike Dix treats a 4-year-old hound mix with severe leg injuries; a 1-year-old Saint Bernard arrives at DogTown with a potentially debilitating disease.
Sherry Woodard visits the no-kill Animal Rescue League of El Paso to help rehabilitate unadoptable dogs to make room for more animals. Back at DogTown, an abandoned shar-pei mix suffers from severe seizures.
The DogTown staff helps a morbidly obese Chihuahua lose weight so it's healthy enough for adoption. Also: a shy Catahoula leopard dog mix overcomes her fears; and a stubborn terrier mix learns to listen.
Sherry Woodard works to socialize a feral dog that was rescued near the Grand Canyon; Dr. Mike Dix seeks help controlling his own beagle mix, which is wreaking havoc in his home; and an elkhound mix is treated for a mysterious disease.
John Garcia works with a traumatized shepherd mix that was rescued during the 2006 Lebanon War. Also: Dr. Patti Iampietro tries to restore a blind Lab's vision; and two neglected Chihuahua mixes are rescued from a squalid home.
John Garcia helps Handsome Dan, a pit bull rescued from Michael Vick's property, overcome his crippling fear of people. Also: Dr. Iampietro tries to find a cure for a spaniel mix suffering from a mysterious illness; and Sherry Woodard works with a rottweiler mix who lashes out at strangers.
In the Season 4 premiere, the DogTown staff continue working with Cherry, a pit bull mix that was rescued from Michael Vick's compound in 2007. Later, investigators from the Michigan Humane Society are followed as they investigate an underground dogfighting ring.