Courtesy Smithsonian’s National Zoo.

The cute animal God giveth and taketh away: The National Zoo announced today that their 23-year-old Przewalski’s horse, Rolles, has died.

Rolles, a five-year resident of D.C. who was born at the Bronx Zoo, was euthanized this morning.

In July, keepers observed that Rolles had some nasal discharge. Zoo veterinarians prescribed oral antibiotics, which helped initially. About 10 days later, he developed a visible mass on the side of his nose. Rolles also lost weight and rubbed the affected area, an indication that the mass caused him discomfort.

Zoo veterinarians, in consultation with an outside equine veterinarian, performed a full examination on Rolles, including X-rays and nasal endoscopy. The location of the tumor greatly limited the options for treatment. Animal care staff elected to humanely euthanize Rolles based on his poor long-term prognosis.

Rolles served a non-breeding companion to 27-year-old Przewalski’s horse, Rose Marie.

In August, the Smithsonian Conservation Biology Institute welcomed a Przewalski’s horse via artificial insemination. The species is endangered, so this was considered quite an achievement. Here’s a photo of Anne and her filly to take some of the sad away from Rolles’ death.

Photo by Dolores Reed, NZP.