SHOWS FOR YOUNGSTERS AND THEIR PARENTS TOO : Nickelodeon takes Lassie for a long run of more than 2 hours

“Ruff, Ruff, Ruff! Ruff Ruff!”

What’s that, girl? You’re going to be featured in a Nickelodeon marathon? And in a Paramount movie opening Friday?

Good girl! Good girl!

Somehow, that brilliant canine Lassie always managed to communicate her message--however complicated--with the many owners she had in the 20 years she was on TV.

On Sunday, Nickelodeon honors the popular collie by featuring her in five classic episodes. The lineup includes two “lost” episodes that haven’t aired on Nick yet, including a show from the 1960 season, where Lassie and Timmy (Jon Provost), one of her earliest owners, are exposed to radioactive chemicals.

Despite the many changes in Lassie’s masters, the show remained popular for two decades, and spawned a sequel series, as well as an animated series.

“People didn’t mind those changes,” Diane Robina of Nickelodeon’s acquisitions department says, “because Lassie was the running theme, Lassie was always saving the day; the foundation of the story was always there. The ones that work best are the ones with Lassie and Jeff (her first owner) or Timmy.”

“ ‘Lassie’ is the ultimate wholesome programming,” Robina observes. “It’s a simple story about a boy and his dog, their connection and that friendship that they have.”

The show has special meaning to children, she says. “Kids connect to the show, they love the animals, and parents like their kids to watch it and can share in it. It could be a nostalgia thing for parents, too.”

“Lassie” originally aired on CBS from 1954 through 1971 and then for three seasons in syndication; Nickelodeon owns all of these shows. An animated series, “Lassie’s Rescue Rangers” ran on CBS from 1973 to 1975.

Now seen on the Family Channel, “The New Lassie” was syndicated from 1989 through 1991 and featured an adult Jon Provost, who was Timmy in the original series.

The “Lassie” marathon airs Sunday from 8:30 p.m. to 11 p.m. on Nickelodeon. “Lassie” airs weekdays at 1:30 p.m. on Nickelodeon. “The New Lassie” airs weekdays at 6:30 p.m. on the Family Channel. For ages 6 and up.

More Family Shows

In “Doug’s Hot Property,” Doug (Sunday 10 a.m. Nickelodeon) feels guilty when the school’s bullies offer to sell him the one Man-o-Steel comic he doesn’t have and that same issue is missing from the local comic bookstore. Also featured Sunday is “Doug and the Little Liar” in which Doug is convinced that Skeeter’s new girlfriend, Loretta, is a liar, and Skeeter is blindly being taken for a ride. For ages 3 to 10.

*

Big Brother Jake (Sunday 7:30 p.m. Family) and his family become the subjects of a documentary in “The Loudest Family.” Jake’s former boss, filmmaker Fred Lomax, tries to make the family appear more “viewer-friendly” through deceit and trickery. Before Jake (Jake Steinfeld) tosses him out, the family erupts in chaos. For ages 4 and up.

*

When an addict is out of control, friends and family have the option of an “intervention”--a supervised meeting at which the loved one is made to confront his addiction and urged to seek help. In Confronting Brandon: The Intervention of An Addict, a Lifestories: Families in Crisis (Tuesday 4 p.m. HBO), a teen comes to terms with his addiction to alcohol and drugs. Andrew Kavovit, Maureen Flannigan, Charlie Heath, Lisa Zane, Trevor Lissauer and Bodhi Elfman star in the drama, which concludes with an appearance by the real-life Brandon Clifton, who credits the intervention and the courage of his family and friends with helping him kick his habit and get his life back in order. For ages 9 and up.

*

Check out Explorers (Saturday 9:05 a.m. TBS), a 1985 action-adventure flick about three junior high friends yearning for excitement and a break from school; starring young Ethan Hawke (“Reality Bites”) and River Phoenix. For ages 4 and up .