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ST. LOUIS (KTVI) – A St. Louis Zoo penguin wearing specially-made shoes is a rare sight — so it’s no surprise that a visitor’s Facebook post about the footwear has sparked more than 9,000 likes.

(Kimberley Washington/St. Louis Zoo)

The St. Louis Zoo told Nexstar’s KTVI that the therapeutic support boots are helping.

Enrique, a southern rockhopper penguin native to the southern tips of South America and Africa and some islands around Antarctica, has developed arthritis in his old age, the St. Louis Post-Dispatch reports. He has been living at the zoo since 2016 and is estimated to be more than 30 years old.

The median life expectancy in the wild is about 10 years, according Dr. Jimmy Johnson, staff veterinarian at the zoo.

“We always say his longevity is a credit to the zoo continuing to provide him with great care and expert husbandry,” Johnson told the Post-Dispatch. “We’re lucky to have had him with us for such a long time.”

Veterinarians noticed Enrique had developed larger, thicker calluses at the bottom of his feet, a symptom of arthritis. He was originally treated with a variety of medicines, topical sprays and creams. Since those treatments needed to be reapplied every time he went for a swim, a more permanent solution was necessary.

“We started thinking outside the box,” Johnson told The Post, “and that’s where the boots come in.”

Johnson told the Post-Dispatch he had seen swans with related types of feet issues that had similar boots made for them. A penguin with a molting issue also got a custom wetsuit so as to not get too cold while swimming.

Zoo officials contacted a New Jersey-based company that makes boots for dogs and cats, called Thera-Paw, to create a cushioned, rubber pair for Enrique. The first prototype pair was received in September and after some adjustments, a new pair was received a month later.

The strap-on shoes are black with red grips at the bottom. Staff members put them on Enrique in the morning and take them off at night before he goes to bed.

Since wearing the boots, zoo officials said Enrique has not required much more medicine for his feet and gets around pretty quickly, the Post-Dispatch reports.