How can summer bring both dog days and shark season?

Turner Classic Movies kicks off a “Dog Days of Summer” film festival, celebrating some of Hollywood’s favorite four-legged performers. Every Wednesday evening in July, Turner Classics will feature cinematic canines, including Lassie, Asta and White Fang, the legendary pooch whose howl (or the absence thereof) tipped off Sherlock Holmes.

The movie pooch-a-thon kicks off with five helpings of Hollywood’s favorite collie. The 1943 classic “Lassie Comes Home” (7 p.m.) stars Roddy McDowall and Elizabeth Taylor, two of MGM’s most promising juvenile stars. June Lockhart, who starred in the “Lassie” television series, appears in the 1945 sequel “Son of Lassie” (9 p.m.), along with future Kennedy in-law and Rat Packer, Peter Lawford. Taylor returned to the franchise in the 1946 feature “The Courage of Lassie” (11 p.m.), co-starring Frank Morgan and Tom Drake. The “Lassie” series continues with the 1948 adventure “Hills of Home” (1 a.m.) starring a very young Janet Leigh, and the 1949 drama “The Sun Comes Up” (3 a.m.) with Jeanette MacDonald.

The “Dog Days” festival will also include short clips and interviews with canine co-stars, including Ben Gazzara, Eddie Bracken and Patricia Neal. These short “bites” will inform viewers about the lives and careers of such screen favorites as Terry, the dog who played Toto in “The Wizard of Oz,” Pal, the collie who played Lassie in seven feature films, and Skippy, star of two “Thin Man” movies.

“Science of Shark Attacks” (9 p.m., TLC) asks the bold question: just why do sharks bite people? After two swimmers from Perth, Australia, were mauled by a great white shark, Craig Ferreria of the White Shark Board conducted bold experiments to see how the big fish react to human presence. Ferreria conducted his test firsthand, swimming with the sharks without any scuba devices or protective gear. And he lives to tell the tale.

“Science” also introduces the creators of the “Shark POD,” a device scuba divers use to prevent attacks, and shows a more than 40-year-old defensive tactic used to create shark-free swimming areas.

More than 50 years of gags and clips unfold on the repeat special “Bob Hope’s Funniest Out-Takes” (7 p.m., NBC). Kelsey Grammer is host to this retrospective, which includes footage from Hope’s television shows, his numerous holiday specials and USO benefits in Korea, Vietnam and other fronts.

Hope’s Christmas Specials from Vietnam remain some of the highest-rated TV events of all time. It’s time that NBC, TV Land or maybe the History Channel rebroadcast these holiday events. They would certainly have historic value as well as a great emotional effect. They might seem a little dated, but so do most episodes of “The Love Boat.”

Tonight’s other highlights

Scheduled on “60 Minutes II” (7 p.m., CBS): repeat reports on overcrowded emergency rooms; a diver discovers sunken Nazi secrets.

The teenage witch looks for enchanting guys in Australia in the 1999 comedy “Sabrina Down Under” (7 p.m., WB).

Bernie’s burnt-out buddy moves in on “Bernie Mac” (8 p.m., Fox).

The multigenerational saga “Mama Flora’s Family” (8 p.m., CBS) concludes.

Former presidents Gerald Ford, Jimmy Carter and Bill Clinton, along with White House aides, look back at their service on a documentary episode of “The West Wing” (8 p.m., NBC).

A homicide case unfolds on “State v.” (9 p.m., ABC).

Cult choice

A psycho coed (Jennifer Blanc) methodically assumes the identity of a fellow student (Shannen Doherty) in the 1997 made-for-television drama “Friends ’til the End” (8 p.m., Lifetime).