The only male giraffe at Wellington Zoo could be put down today after contracting laminitis.
Six-year-old Seun is one of only 650 Rothschild giraffes in the world, and has been with the zoo since 2008.
Wellington Zoo chief executive Karen Fifield said Seun had been in pain for the past five weeks.
"He can't put weight on his hoof. He really is in extreme pain."
Seun first showed signs of laminitis in his left front hoof, which resigned, but his front right hoof now also showed symptoms of the disease.
Specialist veterinarians from Massey University were due at the zoo this morning to help zoo staff to assess the hoof and choose a course of action.
The specialists would carry out X-rays and blood tests.
Fifield said in the worst-case scenario Seun would have to be put down.
"But with our careful consideration, it's about the welfare of the animal, not about us, it's about him.
"The animal has to fight within its own body."
Laminitis is a painful inflammation of the lamellar tissue in the hoof, usually found in horses and cattle.
Wellington Zoo marketing and communications manager Kate Baker said X-rays had not been conducted earlier because anaesthetising a giraffe is extremely dangerous.
"This is the last step you take. This week he was dramatically worse."
If Seun is put down, the cost of a new giraffe for the zoo could reach upwards of $100,000.