An extremely rare event today at Wellington Zoo has seen one of its two Sumatran tigers put under full anaesthetic to treat an ear infection.
The health of the cats - listed as critically endangered - is vital for the future of the species.
"Over the last week or so she's been indicating to us through her behaviour that she's been quite irritated by her left ear in particular," said Amy Saunders, carnivores team leader at Wellington Zoo.
Senja had been shaking her head and twitching her ear, she said.
Today the zoo's specialists sedated the 90kg tiger so they could safely check for an infection. But having a tiger under anaesthetic is such a rarity, the vets also took the opportunity to give her a head-to-tail health check.
They checked Senja's internal organs, blood and saliva, did a dental check up - even moisturising the tiger's slightly cracked paws.
Success is vital in a procedure like this as there are just 400 Sumatran tigers left in the wild.
"We're hoping we can actually pair her with our male Bashi that we have here at the zoo, so it's really important for her own wellbeing that she's nice and healthy but also for breeding as well," Ms Saunders said.
Senja's been at the zoo for five years, but the careful process of introducing the two tigers only started a few months ago.
Her diagnosis is an ear infection, so she's been given a big dose of slow-release antibiotics and a good clean of her ear canal.
The vets say she'll be a bit drowsy, but are confident that she will soon back to her normal self.