Keepers at the National Zoo noticed something was off with Tian Tian, one of their giant pandas.

He had lost some weight during the past few months and they were concerned. His behavior and appetite were normal, but they wanted to “take a closer look as an extra precaution,” officials said.

So they took him to the zoo’s veterinary hospital and put Tian Tian (pronounced t-YEN t-YEN), the adult male panda at the zoo, under anesthesia Tuesday so veterinarians could examine him.

After an ultrasound, blood and urine samples, and some X-rays, the experts deemed him fine. But they think he may have arthritis in his left shoulder.

While he was under, the vets did acupuncture and a laser treatment. They said the acupuncture “may help improve some of Tian Tian’s overall muscle tone” and the laser treatment “may help” with the arthritis.

After his exam, Tian Tian went back to the giant panda house to recover.

Zookeepers said that by mid-afternoon he was reported to be back to his normal routine. He ate bamboo and produce.

Still, the panda team is said to be monitoring him “very closely,” and they’re watching for any changes to his behavior over the next few months. Any changes, they said, would give them a comparison to other tests that have been done on him.