The ZooTampa veterinarian under investigation for medical malpractice that may have killed manatees did not have federal permission to conduct experimental treatments of injured marine mammals, according to a spokeswoman for the U.S. Fish and Wildlife Service.Friday marked the deadline for ZooTampa, formerly the Lowry Park Zoo, to respond to an October letter from the federal agency that said it had received "credible reports" that veterinarian Ray Ball was mistreating injured and ill manatees at the zoo and at Ellie Schiller Homosassa Springs Wildlife State Park."The team at ZooTampa is busy finalizing its response to the U.S. Fish and Wildlife Service’s questions," zoo spokeswoman Kristy Chase-Tozer said. " Our leadership will share those responses and Zoo’s conclusions publicly early next week."She declined to say Friday what conclusion the experts had reached or what the report said, explaining, "The Zoo will brief all media at the same time next week regarding its response."The zoo is responding to questions about whether Ball had accidentally killed at least two manatees with his treatments, administered unapproved drug treatments, gave young manatees the wrong kind of feed, and, on at least two occasions, amputated the flippers of injured manatees and then turned them loose, rather than bringing them back to the zoo for further care.The source of that last accusation turned out to be the Florida Fish and Wildlife Conservation Commission's top manatee care expert, Martine de Wit, who oversees the state's marine mammal pathology laboratory in St. Petersburg. During a 2015 rescue of a manatee that was tangled up in both monofilament fishing line and a crab trap rope, De Wit disagreed with Ball's decision to slice off the flipper and send the manatee back into the water. He overruled her, and then a similar incident took place in 2017. She took her concerns to federal officials because, she told the Times last month, "from my observations other manatee vets have historically brought cases with similar conditions … into rehab for wound care, which is consistent with my own experience of treatment of such wounds."In responding to de Wit's accusation, the zoo's spokeswoman said Ball’s work was supported by a grant that allowed him to experiment with new ways to deal with those kinds of cases. The grant from the National Fish and Wildlife Foundation, according to Chase-Tozer, called for Ball "to develop and implement field treat-and-release opportunities for entanglements, including amputations, and underweight young, independent animals."But according to Rob Blumenthal, a spokesman for the foundation, that’s not accurate. The $302,000 grant to the zoo was intended “to enhance (the zoo’s) capacity to respond to injured marine mammals, including manatees, and increase data collection to inform future management,” he said. The grant also requires complying with all state and federal manatee regulations, he noted.This week U.S. Fish and Wildlife Service spokeswoman Laury Parramore said that the zoo's permit to handle and treat manatees is not sufficient to cover any sort of experimental medical treatment on injured flippers or anything else."That would require a research permit, which the zoo does not have," Parramore said. She did not respond to a follow-up question about what penalty the zoo might face for allowing such treatments without a permit.When asked about the requirement of a research permit to do experimental treatments, Chase-Tozer said this: "While ZooTampa has not been informed by our agency partners of any new regulations or policies, it is always our institution’s priority to work collaboratively with federal and state agencies and to abide by their regulations and requirements in our joint efforts to save and protect manatees."After receiving the federal agency's letter, the zoo convened a panel of manatee medical care experts to review the agency's question and compare them to the records of Ball's work. Once their report is completed, the New York attorney the zoo hired to oversee the committee’s work, James F. Gesualdi, will produce a report for the agency.Since 1991, the zoo has provided care for 400 sick or injured manatees. Ball took over as senior veterinarian in 2010. One former zoo employee said concerns about Ball had been raised previously by the staff, but ignored by upper management.Earlier this year, he self-published a memoir in which he called himself a "rogue veterinarian." He has not commented on the controversy directly except to express gratitude that a reporter had bought his book. Contact Craig Pittman at [email protected] or . Follow @craigtimes.