In the past decade, the owner of Carmen's Dog Training estimates she would have trained about 10 dogs that have managed to graduate the therapy pup program.

"I'm proud of all my dogs," Ms McGill said. "They love their jobs."

They're all special, but 20-month-old siblings Frankie and Xena might be the most special. While Frankie works at the Bidgee School, his sister Xena is down at Forest Hill Public School.

Over the last two weeks, both the pups have graduated the program after passing their assessments "with flying colours", as Ms McGill said.

"It's really great we've got therapy dogs in Wagga now," Ms McGill said.

"They're so valuable to have, but not just in schools, I've got some that have gone into different work environments."

Nowadays, therapy dogs are so sought after it can take up to 18 months of waiting before a dog becomes available for the job.

When Forest Hill teacher's aide Cherrie Godwin received approval for Xena to arrive a little over a year ago, the principal of the Bidgee School, Marianne Mitchell, was still on the list and prepared to face the long wait for one.

But by chance, arrangements with another potential dog owner fell through leaving Frankie in need of an owner.

The two schools were then able to take delivery of their dogs at the same time, and the furry siblings could also stay together for "regular play dates and catch-ups".

To be certified as a therapy dog, the pups have had to undergo a rigorous 12-month training program that tests their comprehension of basic commands and their ability to handle the unexpected.

"They have to cope with the unpredictable," said Marianne Mitchell, principal of the Bidgee School and owner of Frankie.

"Children don't always do what you expect. The training teaches [the dogs] to calm students and themselves, which isn't something they're naturally used to doing."

Their final test to receive their certificate as therapy dogs required they prove themselves efficient and comfortable in noisy, crowded environments with full of stimuli and strangers.

"A school is different from your average backyard," Ms Mitchell said.

Ms Mitchell has recently adopted a second therapy-dog-in-training, with 11-week-old Scarlett the labradoodle arriving at the school last week.

The hope is, Frankie will now be able to model his training to the younger pup.