A visitor shops for pet supplies at the Sofia Zoo Expo 2026 in Sofia, Bulgaria, April 18, 2026. The Sofia Zoo Expo 2026 is scheduled from April 17 to 19 at the Inter Expo Center in Sofia. (Xinhua/Yao Yulin)

A visitor shops for pet supplies at the Sofia Zoo Expo 2026 in Sofia, Bulgaria, April 18, 2026. The Sofia Zoo Expo 2026 is scheduled from April 17 to 19 at the Inter Expo Center in Sofia. (Xinhua/Yao Yulin)

Visitors look at ornamental fish at the Sofia Zoo Expo 2026 in Sofia, Bulgaria, April 18, 2026. The Sofia Zoo Expo 2026 is scheduled from April 17 to 19 at the Inter Expo Center in Sofia. (Xinhua/Yao Yulin)