There’s rampant animal mistreatment at the ‘Tiger King’ zoo — this according to federal authorities — but Jeff Lowe says the findings are misleading and unfair.

The USDA recently completed an investigation into the GW Exotic Animal Park in Oklahoma, and faulted the zoo for not providing proper veterinary care for the lions, tigers and bears. Lowe calls BS on the USDA’s report, though … and claims it’s out to get him.

Here’s some of what inspectors found according to the report — a 16-week-old lion cub named Nala was lethargic, depressed, and so thin she wouldn’t get up from a sitting position even after prompting. The cub was immediately removed from the park and taken to a vet.

Lowe claims Nala was actually rescued from Tim Stark — who was also featured on the ‘Tiger King’ series — and the zoo spent a fortune trying to nurse her and others back to health.

Other examples of neglect — according to the report — include 2 geriatric wolves suffering from arthritis. The USDA says the zoo was “not following the instructions of the veterinarian to provide medication and bedding for the wolves.”

The inspectors also say there was also a grizzly bear found to be extremely thin and a black bear that appeared to be underweight … and both bears reportedly exhibited heightened aggression.

But, Jeff claims the report doesn’t acknowledge that “many of the animals that we house here are at the end of their lives and suffer from arthritis and do lose some weight toward the end of their days.”

He insists the wolves are receiving treatment and the bears are in their proper weight class, and claims they were recently deemed in good shape by local authorities and the Dept. of Fish & Wildlife.

Finally, the USDA claims the charred remains of a 17-year-old tigon, along with a dead tiger, were discovered in a large pile of primarily wood debris in the back of the park. The report says, “There is a foul odor of decomposing flesh and many flies are present on the boards and surrounding areas.”

Lowe did not address the dead animals, but maintains the GW Zoo has weekly vet visits and prior to this report … received 5 clean inspections from the USDA.

He tells us he thinks the ‘Tiger King’ documentary painted a poor picture of the zoo. Lowe claims all of the incidents listed by the USDA in its June 22 report have since been corrected.

As we reported … a whistleblower’s photos of lions suffering from flystrike in June were released to PETA, who sounded the alarm and got authorities involved.