Alfie and Charlie, a Labrador Retriever–Poodle mix and a German Shepherd Dog, respectively, are being trained to detect cancer in humans through a new program at The University of California, Davis.

It is proven that dogs are able to detect certain types of cancer at earlier stages than current screening methods. Dog trainer and physician Dina Zaphiris revealed that the dogs will learn to sniff saliva, urine, and breath for some presence of volatile organic compounds, which are waste products of cancer. The researchers will first work on samples for oral and laryngeal cancers.

Zaphiris, who runs the InSitu Foundation in Chico, California, trains more than 30 dogs to detect different types of cancer. The study is being done in collaboration with Duke University, which is also conducting a similar cancer-detection program.

“Our new canine colleagues represent a unique weapon in the battle against cancer,” Peter Belafsky, a professor of otolaryngology, said in a press release. “It’s the first of its kind at UC Davis, and the dogs’ incredible talent for scent detection could offer us humans a real jump on diagnosing cancer much earlier and thus save many more lives.”

The program would be helpful for cancers that are hard to determine at their early stage like stomach cancers, ovarian, and pancreatic.

The right dogs need to be used in order for the project to be successful. Charlie and Alfie are two of the few dogs that were chosen for the job.

“I love German Shepherds for this type of work,” Zaphiris said, according to AKC News. “For them, it’s more than just the nose; it’s a matter of temperament. German Shepherds have tenacity. They’re tough. They love to work, and they’re not easily startled.”

Meanwhile, Alfie was chosen since a doctor's wife has allergies and Alfie is a hypoallergenic breed. The dogs will live with the doctors during the 18-month training period, which will be completed by mid-2016.