Zoo officials said the first elephant Cha Cha, about 43 years old, had been at the zoo since 1971.
Veterinarians performed an emergency procedure on Christmas after discovering a blockage in Cha Cha's esophagus. They were able to remove the mass, but the elephant's condition continued to deteriorate. Animal care staff made the decision to euthanize her on Wednesday.
The second elephant, Cookie, was estimated to be 56 years old and had been at the zoo since 1981.
Zoo officials said Cookie had several ongoing geriatric conditions. Over the last couple weeks her condition continued to deteriorate and severely affect her quality of life. Animal care staff made the decision to euthanize her on Friday.
Officials said both elephants were part of the Elephant Care Center at the zoo, specifically designed to care for ill and aging pachyderms.