Oregon Zoo Veterinarians Treat Elephant Calf for EEHV
Staff are providing antiviral care to a calf diagnosed with a specific strain of the elephant endotheliotropic herpesvirus.
Updated on Oct. 30, 2026 in Pet Health
Veterinarians at the Oregon Zoo are actively treating an Asian elephant calf named Tula-Tu after diagnostic testing confirmed an active EEHV-1B infection. The calf is currently undergoing plasma transfusions and antiviral medication protocols to manage the illness.
Why it matters
Active EEHV infections pose a significant health risk to elephant calves between the ages of 1 and 8, as the virus is latent in nearly all members of the species. Early intervention is critical to managing the viral load and supporting the calf through the vulnerable period.
EEHV is a latent virus that has been linked to approximately 200 documented deaths in wild Asian elephants. Calves remain particularly vulnerable to the virus's active progression during their first 8 years of life.
The players
Oregon Zoo
This facility is currently providing intensive care and plasma transfusions for the infected calf.
Oregon Veterinary Diagnostic Laboratory
This facility conducted the testing that confirmed the calf had an elevated EEHV viral load.
The details
After staff observed behavioral changes and low white-cell counts on October 24, laboratory results from Oregon State University confirmed the diagnosis the following day. While Tula-Tu previously received an mRNA vaccine for the EEHV-1A strain earlier in 2026, the current infection involves the 1B strain.
Timeline
2018: Another elephant calf died due to EEHV.
2023: Zoo staff assisted in establishing a hematology lab in Sabah.
Earlier in 2026: Tula-Tu received an mRNA vaccine for the EEHV-1A strain.
October 24, 2026: Zoo staff noted behavioral changes in the calf.
October 25, 2026: Testing confirmed the EEHV viral load.
Culture Shift
The zoo's focus on clinical monitoring and vaccination research reflects a shift toward proactive, high-tech veterinary interventions for endangered species. These efforts align with the broader international commitment to mitigating the impact of latent viruses on global elephant populations.
Residents and zoo visitors may notice changes in viewing availability or access to elephant enclosures while the veterinary team manages the calf's treatment. The zoo continues to utilize blood analysis to monitor the health of the herd and vaccine responses.
The takeaway
Early detection remains the most effective tool in managing latent viral infections in young elephants. Owners of exotic animals and researchers continue to emphasize that consistent behavioral monitoring is essential for identifying health shifts before they become critical.
Further reading
Learn more about the latest Pet Health resources and care guidelines.
