The results of an autopsy and laboratory tests, confirmed by the Institut Pasteur du Cambodge, revealed that the cause of Lucky the elephant’s recent death was pyometra (a uterine infection). The findings were announced in a statement on Monday, September 1, by the Phnom Tamao Zoological Park and Wildlife Rescue Center, under the Forestry Administration.
The zoo explained that this disease occurs in female elephants during their reproductive cycle, when fluctuations in the hormone progesterone and thickening of the uterine lining can create a condition favourable for bacterial infection. Bacteria such as Escherichia coli (E. coli) and Enterococcus faecium (E. faecium) can enter through the cervix into the uterus, multiply, cause pus-filled infections and spread to the bloodstream, resulting in severe septicemia.
The bacteria found in Lucky’s uterus were highly resistant to antibiotics, including Amoxicillin/Clavulanic acid, Gentamicin, Ciprofloxacin and at least 10 other types of antibiotics.
“Lucky’s condition was very difficult to treat because antibiotics could not fully penetrate the uterus to eliminate the resistant bacteria. In general, the only effective treatment is surgical removal of the uterus. However, this surgery can only be performed on small animals like dogs or cats. For elephants, such surgery is extremely complex, with very low chances of success,” the statement stated.
Phnom Tamao Zoo expressed hope that this case would help raise public awareness about the complexity of wildlife healthcare and encourage continued support for future conservation efforts at the rescue centre.
Lucky died on the morning of Sunday, August 24, after falling ill suddenly on the evening of Friday, August 22, despite receiving intensive veterinary care.
Over 26 years of care at Phnom Tamao Wildlife Rescue Center, Lucky grew from a small calf into a beloved symbol of strength, gentleness, and compassion — inspiring the public to love elephants and raising awareness about their well-being and conservation.
Lucky’s caretaker, Try Sitheng, remained by her side until the end, even after leaving the NGO Wildlife Alliance. He was present during her illness and is currently working to raise funds to create a memorial statue of Lucky.

