03/16/2012 12:02 pm ET Updated Mar 16, 2012

Thackery And Milo, San Diego Koala Joeys, Receive Clear Bill Of Health After First Medical Exam (VIDEO)

Though understandably frightened after being separated from their mother for the longest period of time yet, koala joeys Thackery and Milo stayed strong as they underwent their first routine medical examination at the San Diego Zoo this week.

The youngsters, born last year at the zoo's large koala colony, were given a clear bill of health after undergoing a series of tests including x-rays and blood evaluations, according to the San Diego Zoo website.

"So this morning, at the San Diego Zoo, we did exams on two of our baby Joey koalas, it's the first exam that they get at seven to eight months, and they both look fantastic," Geoff Pye, senior veterinarian for the San Diego Zoo, told the International Business Times. "It was a little bit of a shock for these guys, it's the first time that they really had an extended period away from their mother, and typically the keepers will weigh them once a week, but it's a very short procedure for that."

Pye explained that the comprehensive medical exams, normally conducted on koala joeys when they are arounds 7 months old, are performed early in order to identify signs of disorders that commonly plague koalas.

"Here at the San Diego Zoo we have seen instances of hip dysplasia in koalas," Pye told Yuma News Now. "We try to do exams on koala youngsters at an early age so we can watch and ensure that they do not have problems as they get older."

With around 123 joeys, the San Diego Zoo's koala colony is the largest group of the marsupials outside of Australia, according to the zoo's website. The colony is currently closed to guests due to the construction of a new habitat, the Conrad Prebys Australian Outback, which is scheduled to open in the spring of 2013.

Though koala colonies once flourished in Australia, their numbers have dwindled in recent years due to a variety of factors including climate change, urban development, and the rampant spread of chlamydia, according to the Telegraph.

Luckily, a number of zoos across the world have introduced programs aimed at saving the increasingly threatened species. The Edinburgh Zoo, which houses some of the few koalas living in the U.K., garnered attention earlier this year when it released an adorable video of one of its koalas running down the halls of the zoo.

Watch the report on Thackery and Milo's exam above and check out the video of the koala at the Edinburgh Zoo below.