So, a baby bongo, eh? Sure, the tiny bounding antelope born recently to the Los Angeles Zoo is cute — but the Cincinnati Zoo and Botanical Garden may have just done them one better: a tiny one-month-old hippopotamus named Fiona, making her parents proud by stepping back into the pool.On Friday, the zoo celebrated the baby hippo's return to pool time with a video of the big moment, which can be watched at the top of this page.On the face of it, this may not seem too big a deal. After all, the zoo says baby Fiona "has outgrown two pools already!" What's another little dip to a hippo so prodigious?But Fiona has had a tough go of it so far. Born six weeks early, more than 20 pounds lighter than the typical birth weight for a Nile hippo, she has received round-the-clock care during her first month of life. The process has been so strenuous, the zoo put out a call for donations to help cover the cost of the care.In fact, when Fiona suffered from dehydration earlier this month, the zoo even reached out to Cincinnati Children's Hospital Medical Center for assistance. Local news station WCPO reports the hospital's Vascular Access Team, a group that works with prematurely born (human) children, helped place an IV in the little hippo.The swim depicted in Friday's video was Fiona's first since the dehydration scare. Zoo researcher Jessye Wojtusik told WCPO that swims like this one help build Fiona's strength, which is crucial before Fiona can finally be returned to her mother, who is being kept nearby."We love [Fiona] to pieces," Wojtusik said. "She's at about 50 pounds now — so she's about what she should have weighed when she was born."Now, Wojtsusik says baby Fiona faces her next grand challenge: teething. Copyright 2017 NPR. To see more, visit http://www.npr.org/.