Did you know a horse has a frog?

Callie Jo Clark does. She can even show you where to find it.Cupping her hand as if it were the hoof of her muscled sorrel named Rocky, the 13-year-old junior high student explains the important role of the strangely named animal part.

"It's the groove inside the hoof," she explains, flashing a grin with a mouthful of braces.

"It's known as the second heart because it pumps blood, and it also absorbs shock." Clark, a seven-year member of a Davis County riding club, has committed such veterinary terminology to memory. And she's not about to forget it.

Rigorous tests are given at each summer 4-H horse show for points toward an all-around prize, including the state championship competition.

"I don't like those tests. They ask you how long the intestine is and the systems and parts. The true and false are kind of tricky," she said. "I'm better off on my horse."

Clark, whose parents, Mike and Beverly, were reared around horses, has earned her place at the final show for several years - capturing nods from judges handing out rosette ribbons for Western pleasure contests. She favors the fast-paced, clover-leaf, barrel-racing competition, however.

Callie Jo, who works the family's steeds with brother Preston, is quick to say one of her best friends is her horse. But cultivating the relationship can be a lot of hard work.

In addition to training a horse to perform tasks in the arena and caring for its well-being throughout the year, participants in the 4-H horse program must learn such animal-science basics as equine nutrition guidelines, proper safety measures and how to treat common causes for lameness.

"I have to feed and water every day and make sure they have salt blocks," she said.

Cleaning out stalls, especially for this teenage girl with a more of a fixation on horses than boys, is the most unenviable of the barnyard tasks.

"That's a pain in the butt," she said, giggling.

Callie Jo and Preston are two of some 1.8 million American kids who spend their summers training a horse, raising a rabbit or fattening a swine in a 4-H animal-caring program.

Unlike in other animal programs, most of the horse owners don't sell the animal at the end of the year. Instead, the horse is trained over several years to excel in such show events as showmanship at halter, Western pleasure and reining.

Caring for animals is the most popular option for the estimated 5.6 million youths nationwide who participate in 4-H classes.

Good thing some 40 percent of club members live on farms or towns of less than 10,000 residents, where zoning ordinances usually don't prohibit livestock within the city limits.

Country bumpkins and city slickers alike line up for courses in topics as varied as tractor repair, cross-stitch sewing and computer technology, according to the national office.

The roots of 4-H were planted in 1862 when the Morrill Act funded the creation of land-grant colleges and universities, which were charged with organizing the developing agricultural-based education programs in the community.

To spark the interest of young people, Farmer's Institutes and school officials sponsored farming clubs for boys and girls. Many started exhibiting projects at county fairs.

By 1912, Congress was allocating money to the schools for extension services throughout the country. Two years later, the Smith-Lever Act established a Cooperative Extension System within the USDA, the land-grant schools and counties.

Utah State University, which is often called the "Ag school" by older folks, was the Beehive State's link to the extension service, which it still manages.

The organization's four "H's" stand for head, heart, hands and health.

At the beginning of each show, before saddles are dusted off and the gate swings open for the first contestant to meet the judge, all participants huddle in a circle and recite the motto: "I pledge my head to clearer thinking, my heart to greater loyalty, my hands to larger service, and my health to better living, for my club, my community, my country and my world."

A show at the Lehi rodeo grounds recently was a chance for Utah County 4-H'ers to be critiqued by a judge before the final competitions.

High placings in shows throughout the summer earn points to get a place on a county team that will face off against other top show girls and boys from other Utah regions in the fall.

Winners often receive tack, such as halters, blankets and brushes. Some shows also hand out trophies and ribbons to winners.

Angie Burton, 20, looks back on her two years in a Weber County 4-H program with fondness. Enthralled with horses' powerful strides and flowing manes, Burton, who didn't have a trained steed, borrowed a neighbor's horse to enter the weekly shows.

"I think I got most of my skills from that old palomino," she said, laughing. "But I most definitely think it is a good program to develop fundamental skills."

Burton has won five trophy saddles in horsemanship competitions and was last year's Intermountain Reining Association's top rookie competitor.

At 14, she leapfrogged out of the 4-H program into the Utah high-school rodeo circuit, winning Miss High School Rodeo Utah and was runner-up to the national rodeo queen.

The Weber State University sophomore, known by friends to have a one-track-mind that is bearing down on a goal to win Miss Rodeo America, rides her two horses, Madison and Cinnamon, daily.

"You learn many skills in 4-H," she said. "I wish I would have paid more attention."