In this July 7, 2017 photo, two lions sleep on a rainy day inside their enclosure at the Dr. Juan A. Rivero Zoo in Mayaguez, Puerto Rico. Danica Coto / AP

San Juan, Puerto Rico — Federal inspections at Puerto Rico's only zoo have found animals sacrificed inhumanely or for unclear reasons, inadequate veterinary care and a string of other problems.

The reports obtained by The Associated Press span a decade up to its closure in 2017 and show inspectors accusing one former zoo veterinarian of covering up animal deaths, as well as complaining of expired medications, dirty and dilapidated enclosures and the presence of only a part-time veterinarian.

The documents on the Dr. Juan A. Rivero Zoo in the western city of Mayaguez were released by the U.S. Department of Agriculture following a Freedom of Information Act request.

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Among the most troubling findings is a 2014 report in which an inspector stated that a puma, coatimundi and baboon were euthanized because they were "not fit for exhibition."

"When I questioned this, the veterinarian really had no explanation. I find this disturbing. If these animals were not 'fit for exhibition' why did the zoo let them get this way without veterinary care or intervention & then decide to euthanize them," the inspector wrote.

The zoo has been closed since Hurricane Irma brushed past Puerto Rico in September 2017. Animal rights activists say they're worried about the state of the animals and haven't been allowed to see them.

The secretary of the island's Department of Natural Resources, which is expected to take over the zoo next year, issued a statement this month acknowledging the facility's problems and saying that a proper inventory of all animals still needs to be done.

"The zoo's historical problems, worsened by the passage of hurricanes Irma and Maria, are complex and their resolution requires large injections of money, strategic planning ... and the development of a new public policy," said Secretary Tania Vazquez. "There are still a good number of animals that are sick or in delicate condition and deserve a careful evaluation."

However, Yeidy Acosta, the zoo's administrative assistant, told the AP on Wednesday that no animals died or were injured during Hurricanes Irma and Maria.

"The animals are doing very well," she said, though she confirmed that the zoo still has only a part-time veterinarian.

She said the zoo hasn't reopened in part because officials are awaiting insurance money to repair the structural damage caused by the hurricanes. The zoo's federal license expired in February and has not been renewed.

Spokespeople for the USDA's Animal and Plant Health Inspection Service did not return messages for comment. Neither did Alex Castro, spokesman for Puerto Rico's Department of Sports and Recreation, which still operates the zoo.

The environment department had launched an investigation into recent animal deaths reported at the zoo, but it is unclear whether it has been completed.

One federal inspection report noted that two guinea pigs on exhibition were fed alive to reptiles, and that deer on exhibition were fed to big cats after having their jugulars cut without using a humane slaughter method.

"These instances are not humane methods of euthanasia, and since the health status of these animals is not really known, it does not minimize disease transmissions &/or parasite infections to the animals being fed," the report stated.

In addition, inspectors reported that two impalas broke their necks shortly after they were introduced to other animals, that a sugar glider was killed by a rat and that one raccoon was killed by another.

"Again, I also have concerns about the caretaker's knowledge & experiences in caring for these species of animals," the inspector wrote. "All of these occurrences suggest that there is a problem with several aspects of the zoo's operation, procurement process, finances, and veterinary care."

One of the most recent reports noted that a cougar was exhibiting distress and was housed in a small enclosure, and that one of the tigers was thin but had not received any laboratory tests or other examinations for two years.

The zoo's administration has previously said that it was struggling due to a 12-year economic recession and efforts to restructure part of the U.S. territory's more than $70 billion in public debt load.

The zoo was operating on a $1.7 million budget that was recently slashed to $526,000. The former head of the island's veterinary medical association, Victor Oppenheimer, estimated last year that the zoo would need at least $8 million a year to operate properly.