Poor recordkeeping contributes to animals' deaths.

An independent study of the National Zoo in Washington, D.C., has revealed problems with animal care, recordkeeping, and pest control. The interim report, part of a year-long study done for the U.S. Congress by the National Academy of Sciences, says the zoo has fallen behind on ensuring its animals have annual exams and other preventative care and has failed to follow its own policies and procedures.

The summary states that the zoo's recordkeeping is so poor that some veterinary records had been altered "weeks and years" after animals were treated. The summary flagged shortcomings in the zoo's animal nutrition program, saying it has not coordinated efforts between its nutrition, keeper, and veterinary staffs and has failed to regularly evaluate diets.

The science panel said pest control efforts have shown signs of improvement but remain inadequate and may potentially threaten the animal collection, employees, and visitors.

Zoo director Lucy H. Spelman, who said she would resign her position at the end of the year, said veterinarians fell behind on examinations and testing because they were short staffed. The staffing issue has been corrected, she said, and the zoo is taking steps to improve nutrition, pest control, and recordkeeping.

The report marks the fourth time in the past year that problems with the zoo's operations have been flagged in an independent review. An audit released in March 2003 by the American Zoo and Aquarium Association found that the zoo suffered from crumbling buildings, a stagnant animal collection, morale problems, and insufficient funding.

The study was commissioned by Congress after two endangered red pandas died in 2003 after eating rat poison that had been buried in their yard to kill rodents. A review of nutrition and recordkeeping revealed details about the deaths of two zebras from hypothermia and starvation.

A Washington Post series published last year found that neglect, misdiagnosis, or other mistakes had marked the deaths of 23 animals in the past six years. The series also revealed that records were changed or were incomplete in files on eight animal deaths.

The mortality rate at the zoo has dropped from just over 10 percent to about 7 percent in recent years.

Panel Chairman R. Michael Roberts said there is a "pervasive weakness at many levels within the system, ranging from the keeper level through management."

The final report, due this summer, will provide a more extensive assessment of the zoo.