Some days Margie Kendall walks as many as 13 dogs. Three times a day each. She's as regular as the mail carrier, maybe more so. But even she has her limits: no pit bulls, no Rottweilers.

In the unforgiving heat of summer, Kendall, 52, maneuvers a golf cart around the gravel streets of a campground tucked in the crook of the road where the Capital Beltway meets Interstate 95 in College Park. She goes from one site to another, leashes up a pooch and commences to walk.

"Hi, Ruby, how are you, dumpling?" she greets a chocolate Labrador. "C'mon, baby," she coos. "C'mon Ruby, you ain't gonna smell every blade of grass."

Seven days a week, Kendall walks the dogs of Cherry Hill Park, a mecca for the traveling RV set in search of inexpensive lodgings while they tour their nation's capital.

The pooches come from all over the country. As their owners go about having what the park touts as a "monumental experience" seeing the sights of the District, man's best friend is left behind at the RV park, awaiting nature's call.

"Go potty," Kendall instructs a little Yorkshire terrier, her voice that of an eager parent coaxing a 3-year-old.

"That's a good girl," she praises a Shih Tzu who has done her business.

Kendall, Cherry Hill's third dog-walker in five years, charges $5 per day per pet for her service, which includes bird-sitting. But mostly it's dogs. Walking them can take up to six hours a day because Kendall prefers slow, 20-minute meanderings, not aerobic workouts.

She does, however, bend down to clean up after her charges. "Some of 'em will go right away for you. Some of them don't never," she says.

All are rewarded with dog biscuits, which Kendall buys herself, investing "probably $10 a week."

She's had dogs that scared her and dogs that were scared of her. "C'mon, Gypsy, I wouldn't hurt you for nothing," said tells one of two Yorkies she is walking at the same time--an exception to her usual practice. "This one's timid," she says of Rachel. "Gypsy, she pulls you."

At Cherry Hill Park, Kendall has walked everything from tiny poodles to huge Newfoundlands, one of which she swears weighed 350 pounds. A dog owner herself, she lives at the park year-round and works in the office when she's not out walking dogs.

Returning the visiting Shih Tzu to a Chevy conversion van, Kendall sees the dog begin to shake. "She's scared," Kendall says. "You want to go home? It's right here, baby." Once inside the van, the dog begins to growl and Kendall has to leave her leashed.

"She's just nervous," Kendall explains. "I'll come back, see if she'll make up. Well, how would you like it if some stranger came in and got you?"

CAPTION: Ruby, a chocolate Labrador whose owners are staying in Cherry Hill Park, delights in a walk with Margie Kendall, who tends to the pets of campers staying in Cherry Hill while visiting the area.

CAPTION: Oliver, a severe macaw, cavorts on the finger of John Novak, a staff member at Cherry Hill.