ATLANTA — As passenger lines at security checkpoints grow, Atlanta airport officials think one solution could be more screeners like Miley, Jo and Dougie.

They are part of Hartsfield-Jackson International’s five-dog squad of four-legged security screeners, and aviation general manager Miguel Southwell thinks having more could help speed the flow and hold down rising waiting times.

“Either additional inspectors or additional canine units — we need those right now,” Mr. Southwell said. “I believe we could use about four to five more canine units or the equivalent in the number of employees.”

The trained dogs patrol lines at screening checkpoints, sniffing for explosives or potential bombmaking ingredients on passengers and their carry-on bags.

Their presence gives the Transportation Security Administration a form of expedited screening, as passengers scrutinized by dogs might be able to keep their jackets or shoes on or leave their laptops in bags to speed the lines.

In addition, the dogs bring “a degree of comfort and security” to passengers, said the TSA’s Atlanta canine supervisor, Anthony K. Jones.

Long lines have become a more urgent issue over the past year, with waiting times at the world’s busiest airport reaching as long as 52 minutes during peak travel periods.

Mr. Southwell last month said he was considering the drastic step of privatizing security if the TSA — whose overall screener force is smaller now than it was five years ago — cannot cut waiting times.

He has since talked with the agency and said he believes it will bring “additional resources, including employees, canine teams” and new technology to process passengers.

During the recent holiday rush, extra dogs from Fort Lauderdale, Fla., helped at Hartsfield-Jackson, Mr. Southwell said. But those teams were returned afterward.

Now Mr. Southwell is worried about the summer rush, writing in a Feb. 12 letter to the TSA that airport officials are “dreading” long waiting times.

During the busiest travel days, such as the Sunday after Thanksgiving, TSA screens as many as 88,000 passengers in a day at Hartsfield-Jackson.

TSA’s five certified passenger screening canines at Hartsfield-Jackson are Miley, a chocolate Labrador retriever; Jo, a German shorthaired pointer; Dougie, a yellow Lab; and Balou and Betty, both black Labs.

The TSA refrains from using pointed-eared dogs like German shepherds, which can appear more threatening.

There’s already funding for four more dogs that are still in training to work at Hartsfield-Jackson. Other TSA dogs are used to screen cargo.

The bomb-sniffing dogs work in half-hour to one-hour shifts at the main security checkpoint, sniffing passengers, their bags and the air for any hint of explosive materials.

It’s tough work, Mr. Jones said.

“As many people as Atlanta pushes past these dogs, they’re trying to catch each one, they’re pretty exhausted,” he said. “You can see it … [The dog’s] tail is not wagging like it used to be, he’s dropping his head a little bit more.”

Each canine team costs as much as $220,000 in the first year to cover the handler’s salary, training and certification, veterinarian services, kenneling, dog food, a climate-controlled vehicle for the dog’s break periods at work and other equipment, according to TSA.

Basic training takes place at Lackland Air Force Base in San Antonio, Texas.

“All dogs are not cut out for this,” Mr. Jones said. “Some dogs wash out.”

The training is followed by an acclimation period at the airport and operational training, with tests to see if they detect training aids. Dogs learn the area where they are expected to work.

“Basically, the checkpoint is their cubicle,” TSA spokesman Mark Howell said.

The dogs work for rewards — tennis balls, rubber toys and most important, a “Good boy!” or “Good girl!” from their handlers.

When not on duty at Hartsfield-Jackson, the dogs go home with their handlers. But they are not treated as pets and typically stay in kennels when off the job.

If being home is nonstop play time, “the dog is not going to want to work,” Mr. Jones said. “Their fun is working.”

First Published: March 13, 2016, 5:00 a.m.