Treatment of all of our animals involves the zoo keepers and veterinary staff, and in our pygmy slow loris’ case, specialists from El Paso and around the country. Earlier this year, our pygmy slow loris keepers began training our male loris, Steven Tyler, through operant conditioning to allow palpation of his limbs and body. This is important as a loris has thick fur that can hide abnormalities. During one of their training sessions they felt a hard lump on his back. He was brought to the Animal Medical Center at the zoo for a biopsy under anesthesia. The biopsy indicated Steven had a cancerous mass called a fibrosarcoma. A CT scan was performed in order to better visualize the mass. Due to the large size of the tumor as well as the invasive nature of this type of cancer, specialists were consulted for the best course of treatment for our small loris.

After consulting veterinary oncologists from Houston and New York and a local veterinary surgeon, a treatment plan for Steven was formed. The surgeon removed the mass from Steven’s back but because microscopic cancerous cells can be left behind, electrochemotherapy was performed two weeks later. Veterinary oncologists flew to the zoo for this specialized treatment which shocks the cells to allow the chemo drug to enter into the cell. Throughout our loris’ treatment and recovery keepers and veterinary staff provided special care to make sure Steven was comfortable, healing well, and had the proper nutrition to recover.

Steven is now on exhibit, but continues to recover and is closely monitored daily by his keepers. He has scabs on his back from his large incision, but is healing normally. Although continued monitoring for reoccurrence of cancer is necessary, we have high hopes for a good response. Steven’s treatment is just one example of a cooperative effort between our animal care staff, veterinary staff, and specialists to provide a treatment that would offer the best outcome for our loris. 


El PASO, Texas – The El Paso Zoo is currently looking for volunteers. The Zoo is open 362 days a year, closed only on Thanksgiving, Christmas Day, and New Year’s Day, and volunteers are an integral part in helping keep the Zoo operable year round.

The Zoological Society continually seeks enthusiastic, friendly, dependable individuals that care about animals and environmental conservation. The Volunteer Program is open to individuals of all ages, 18 and up. However, we are currently focused on finding volunteers who are available year-round as well as retired and senior volunteers. We want people to know “You’re never too old to monkey around.”

“It’s been an incredible experience here at the Zoo,” said Tom Marsden a current volunteer. “When I retired, I enjoyed my time off, but I still wanted to contribute somewhere. I started volunteering with the Zoo, and I’ve had so much fun. I’ve had the opportunity to provide tours, help with education presentations, and help Zoo staff with event projects. I love it.”

The Zoo is looking for dedicated volunteers who have a flexible schedule, can work throughout the week, have year-round availability, and can volunteer a minimum of eight (8) hours a month. There is a volunteer orientation for approved volunteers coming soon. For more information and to find and download the online volunteer application, go to or contact the El Paso Zoological Society Volunteer Department. This email address is being protected from spambots. You need JavaScript enabled to view it. (915) 212-0244.