The El Paso Zoo regrets to announce the loss of a 32-year-old Lion-tailed macaque, Tango.

Tango, was a geriatric lion-tailed macaque and was euthanized late afternoon on Friday, April 17, 2015.

According to the El Paso Zoo staff, Tango had a history of severe arthritis but no other serious medical problems. He was observed acting normal the day before he was found on the ground and unconscious with a head wound by zoo keepers on Friday morning. Staff believes that he fell but is unaware of what caused the fall and even with arthritis, macaques are excellent climbers and rarely fall.

Veterinary staff was immediately notified and Tango was provided intensive care throughout the day. He initially became slightly responsive but began having complications as the day progressed. Complications included an abnormal heart rate and difficulty breathing. Due to his advanced age and limited mobility, veterinary staff performed euthanasia instead of pursuing more aggressive treatment.

The cause of his fall is unknown at this time. Necropsy reports are pending and may help provide more information about any underlying medical cause.

Lion-tailed macaques are listed as ‘endangered’ in the IUCN Red List of Threatened Species and are a part of the AZA Species Survival Plan Program.