On the evening of June 1, a young lioness was found gasping for air inside her cage at the Arignar Anna Zoological Park or Vandalur Zoo in Chennai. The nine-year-old Asiatic lion, named Neela, had a runny nose, bouts of cough and a high fever. As the zoo’s doctors watched her from outside her enclosure, a weak and panting Neela suddenly collapsed, her paws unable to hold her weight. Neela stopped breathing and died within 24 hours.
Neela’s death came as a shock to Dr Sridhar K and his team. But when nine out of the 15 Asiatic lions in the zoo began losing their appetite and showing acute signs of cold and breathlessness, Sridhar knew that they were dealing with something unusual.
“We had suspected COVID-19 but were not sure why the animals were so sick, as coronavirus positive lions in other zoos were asymptomatic,” Dr Sridhar, veterinary surgeon at Arignar Anna Zoological Park tells TNM. However, by the night of June 1, Dr Sridhar's suspicions were confirmed. Vandalur’s nine lions, Neela included, had been infected with the SARS-CoV-2 Delta variant, a highly transmissible strain in India which had caused acute respiratory distress and death in humans during the second wave of the pandemic. From Neela’s case, the zoo authorities knew that this infection had the potential to kill their lions within days.
Over the next 50 days, the zoo’s team donned their battle gear to fight the biggest battle of their careers. In an interview with TNM, Arignar Anna Zoological Park’s Deputy Director, Sathish Gidijala IFS and Dr Sridhar recount the intensely stressful, sleepless months their team spent treating, screening, closely monitoring, and finally saving 13 out of the 15 lions at the zoo.
Even a week before Neela’s death, things were not fine at the lion’s safari area. Spread over 18 acres, the lion's safari area of the Vandalur zoo is where its 15 Asiatic lions are housed. The park has built-in animal houses or cages with huge grassy paddocks known as day kraals. When bored of the indoors, the lions are free to move around in the day kraals and take in all the sunshine.
According to Dr Sridhar, most healthy lions typically roar at least once a day in a ritual called a “presence call”, performed to communicate and establish their presence. Sridhar recalls that all 15 of Vandalur’s Asiatic lions would make their presence calls one-by-one every evening, which could be heard from a radius of 15 kilometres. But that week, none of the lions roared.
A coronavirus positive Asiatic lion in the zoo
Instead, four of them were coughing for 20 seconds straight and had runny noses. This included 23-year-old Bhuvana and 19-year-old Kavitha - the park's oldest lions. In lion-years, a 23-year-old is equivalent to a 100-year-old human being. The vets at the park knew that testing Kavitha and Bhuvana for SARS-CoV-2 and treating them would be among their biggest challenges.
“It is not so easy to take nasal swabs of lions,” says K Sridhar says with a laugh. The park did not want to sedate their lions as that would further weaken their immunity. So they used squeeze cages, which have a hydraulic mechanism to make the cage smaller when an animal enters it. The park’s vets collected the nasal swabs of all four lions - including those of Kavitha and Bhuvana - by restraining them in squeeze cages. These samples were then sent all the way to a laboratory in Bhopal’s National Institute of High Security Animal Diseases (NIHSAD), an authorised institute for testing animal samples for pathogens.
Five days later, Neela died in her cage and the NIHSAD confirmed that the four lions whose samples were sent were positive. By then, Neela’s two-year-old lion cubs - Niranjana and Pradeep - too began to sneeze and show symptoms of distress. “The cubs were really missing their mother. For days together they kept searching for her among the lions and would lie down and look in the direction of her cage,” Sathish adds. The zoo then tested Pradeep and Niranjana and four more lions for COVID-19. Within days, their reports arrived positive for the coronavirus. The remaining animals that were not tested were considered positive for the coronavirus as they were all in the same lions safari area and were treated as such.
After establishing COVID-19, it was what the zoo did next that geared them up for aggressive response. The authorities got a genome sequencing of the coronavirus which revealed that the lions were infected with the highly contagious Delta variant. To fight this variant, the team knew that they had to go on a warpath.
The zoo's team before visiting the animal cells
“The SARS-CoV-2 Delta variant had killed many patients in the second wave. I had heard of people who suffered respiratory failure and died within a day. And I had seen the exact pattern with Neela. Out of the blue, she started getting breathless and collapsed to death. That is when I knew that our lions were in serious trouble,” Dr Sridhar says.
While human beings can be put in an Intensive Care Unit (ICU), intubated and monitored for blood oxygen levels (SpO2), with wild animals things are way more challenging. Despite the virus affecting the lions much like it does humans, it was impossible to monitor their SpO2 levels, to clip their tongue or tail and check their vitals. The big cats can neither be sedated nor be put into a CT machine to look for lung damage, Dr Sridhar recounts. “The only thing we could do was to keep our eyes wide open and observe their symptoms day and night,” Sathish Gidijala adds. The only thing the authorities got was a digital thermal scanner to check the temperature rise in the animals without touching them.
The zoo’s team knew that the very first step to fighting the virus was to learn everything they could about the infection and animal responses. So they brought experts, including the dean of wildlife and the head of animal internal medicine, of the Tamil Nadu Veterinary and Animal Sciences University (TANUVAS). The team also contacted all the zoos in India which reported animals getting COVID-19, and spoke to the vets at the New York City’s Bronx Zoo, where the tigers and lions had tested positive for the novel coronavirus in April 2020. “We wanted to give the best treatment from across the world for our lions,” Dr Sridhar says.
After Neela’s death, the zoo's remaining 14 Asiatic lions were put on steroids, broad spectrum antibiotics and antipyretics to reduce their fever. They were also given lots of vitamin supplements and immunity boosters. Generally, these drugs are mixed with the feed and put in their cages. But in Vandalur, most of the sick lions had stopped eating for days together.
A coronavirus positive lion being nebulised in Vandalur zoo
Before they stopped eating, these lions were fed 9 kilograms of beef in the evenings at the park. But for a week, most of them had been ignoring the lumps of meat that the keepers left in their cages. Dr Sridhar then changed their meals. “Instead of beef, we tried mutton and chicken to see if they were eating. Some lions like Bhuvana and Kavitha found it difficult to eat solids. So we gave them mutton soup with medicines mixed inside. We even left platters of mutton, beef and chicken so that they had options to pick from. This worked and the animals began to take their feed,” Sathish says.
The medicines that couldn’t be mixed with the food had to be injected. Dr Sridhar says that the lions were very angry with him and the other zookeepers and started to avoid them as they did not want injections.
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Dr Sridhar about to dart a COVID positive lion
“They would refuse to move and come to the squeeze cages when they saw me. So I began to hide and get the zookeepers to bring them to the squeeze cages. Once they were inside, I would quickly come out and inject them, much to their displeasure,” he adds with a laugh.
When injections didn’t work, Sridhar and two other vets would dart the lions with drugs. These darts used to irritate them so much that they would chase the vet from inside their cages, he says. For the really unwell lions, fluid therapy or saline treatment was started. To do this, IV (intravenous) tubes have to be inserted into the tail vein of the lions. “It is an incredibly tough task. Sometimes the lions would bite the tube off and we would have to distract them to stop them,” Dr Sridhar adds.
Just when it seemed like the 14 lions were in recovery mode, tragedy struck again. The zoo lost another Asiatic lion - this time a 12-year-old male called Pathbanathan - on the night of June 15. He was found dead in his cage and CCTV visuals showed that Pathbanathan had collapsed without taking any feed.
Performing a post-mortem on a suspected COVID-19 animal was inadvisable due to bio safety concerns. “There is no clarity on the specific variant, how the animal was infected, how the virus has mutated inside the animal, whether there are chances of animal-to-human transmission,” Sathish says. However, the park wanted to know how Pathbanathan succumbed and therefore, decided to do a restricted post-mortem. “What we found was that he had died due to respiratory distress. There was mucus accumulation in the lungs due to which he could not breathe. His lungs suffered considerable damage,” Dr Sridhar says.
On more than one occasion, the vets risked their safety to help lions in distress. For example, back when Neela collapsed, Dr Sridhar entered the cage and performed CPR (cardiopulmonary resuscitation) on her by compressing her chest. “It was a desperate attempt and an instinctive act. However, it didn't work on her,” says Dr Sridhar, who shared a special bond with Neela. The nine-year-old was friendlier and more interactive compared to the others, he recalls. “She would run to me when I visited her cage and allow me to pet her. At the time she collapsed I knew it was safe to enter the cage as she was very familiar with me and was not in a position to hurt me,” he adds.
Zookeepers disinfecting their feet in pottasium permanganate solution before entering animal cells.
Perhaps the most challenging aspect for the Vandalur team was ensuring personal safety for themselves, as they had to work long hours in PPE (personal protective equipment) suits. Everytime, they went close to the lions, the three vets and the 10 zookeepers working in the lions safari, the enclosure, and the rescue centre would wear PPE kits and protective headgear. On most days, the team worked in PPE kits in the sunny zoo for 11-12 hours a day, and then took shifts to observe the lions.
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Daily temperature monitoring of COVID positive lions in the zoo
Their efforts, slowly but surely paid off. All the 13 lions showed sure signs of recovery. Kavitha and Bhuvana, who were the most vulnerable of the lions, stopped coughing and gained back their appetite. “Now they are feeding well and roaring everyday,” Dr Sridhar says. However, the authorities are still observing the animals closely, monitoring their feed, faeces and looking out for symptoms. On July 24, the zoo reported that all of their lions were COVID-19 negative, after collecting and testing their nasal swab samples at NIHSAD, 50 days after the lions first tested positive.