Drugs are all fun and games — at least to detection dogs.

Narcotics detection dogs for the Texas Department of Public Safety have a blast sniffing for cocaine, marijuana and other drugs. To them, the hunt for illicit substances is a constant game of fetch.

Lizzy, a longhaired yellow Labrador who has been a DPS detection dog for two years, once uncovered 452 pounds of marijuana in a pickup's gas tank, toolbox and false bed. Her handler, Trooper Denney Bowen, said he loves working with her.

“And she loves me,” he added.

When Bowen and Lizzy aren't working their 12-county area surrounding San Antonio, they continue training eight hours a week.

Right now, the agency has 33 canine teams — each consisting of a trainer and a dog — working across the state. It usually has 38, and three of them search for explosives. The rest stick to drugs.

So the department is looking for five trainable pooches and is scouring private and public kennels and shelters. Donations from the public are accepted.

Whenever there's a vacancy, DPS Capt. Justin Chrane activates an online donation form, which can be found on the DPS Web site. He did so June 18 and within a week received eight responses. Troopers also spread the word by contacting local animal agencies.

To qualify, dogs must be 1 to 3 years old, weigh between 50 and 100 pounds, be in good health, and have good stamina and temperament, Chrane said. They also need to have a near-frantic desire to retrieve.

The dog's breed, whether purebred or mutt, has no effect on the dog's ability to detect drugs, he added.

“These dogs are bold, very alert and inquisitive,” Chrane said. “They want to go around and try different things. They aren't afraid of going up stairs.”

Accepted dogs are enrolled in an 11-week canine school in August. Graduates become DPS drug dogs.

Lizzy, 5, was a bird dog, until her owner contacted DPS and asked to donate her. Paired with Bowen, she's not interested in cocaine or marijuana — she just wants to find her towel and play a good game of tug-of-war with him.

Bowen is her whole world. For his part, he spends more waking hours with Lizzy than with his wife.

Lizzy's obsession with rolled-up towels stems from retrieval games played while training. Eventually, the towels are scented with different narcotics, and dogs associate the smells with their towel.

“(Searching) is all a game to them,” Bowen said. “They are just looking for their towel.”

From her kennel at Bowen's home, if Lizzy sees Bowen in uniform or hears his patrol car she gets excited and starts jumping. She knows it's time to work, to play.

“She's real keen to what she's doing,” Bowen said. “It's a pleasure to play with a dog eight hours a day.”