Behind the Scenes: Caring for the Zoo’s Most Dangerous Patients

As the Zoological Society of London marks its 200th anniversary this spring, Guardian photographer David Levene has captured a year following the charity’s elite veterinary team, capturing the remarkable difficulties of caring for some of the world’s most dangerous and endangered animals. From anaesthetising a king cobra that responded to anaesthetic with a toxic discharge to assessing an Asiatic lion’s unusually narrow ear canal, the vets, nurses and specialists employed at ZSL’s facilities in London and Whipsnade manage medical emergencies that few other professionals ever encounter. With just a small number of British zoos employing their own resident vets, ZSL’s five-strong veterinary team, nursing staff of six, a animal pathologist and several specialists represent a rare breed of medical expertise—one that has pioneered animal welfare practices for 200 years.

A Year of Unprecedented Healthcare Difficulties

David Levene’s extended photo documentation uncovered the unpredictability of zoo veterinary work. On his second visit, the documentarian found himself face-to-face with Bhanu, an Asiatic lion afflicted with persistent recurring ear infections that had left him with an unusually narrow ear canal. The condition necessitated a general anaesthetic—always a final option in zoo medicine—so the animal care specialists could perform a comprehensive assessment. Whilst Bhanu was sedated, the vets seized the opportunity to perform comprehensive health checks, including careful examination of his teeth, which are essential for a carnivore’s wellbeing and survival in captivity.

Perhaps the most remarkable moment came when King Arthur, a young king cobra and the world’s longest venomous snake, received his anaesthetic injection. The reptile reacted to the sedative with characteristic aggression, rearing up and spitting directly at Levene through the protective glass barrier. “I was the first person he saw after he’d been injected in the tail,” Levene recalls with wry humour. One bite from the young snake could be fatal to an elephant, yet the ZSL team handles such extraordinarily dangerous patients with practiced care and unwavering professionalism.

• King cobra displays anaesthetic with venom-spraying display
• Asiatic lion demands sedation for aural examination
• Veterinary team carries out several health assessments during anaesthesia
• Zoo medicine calls for expertise with exotic and hazardous species

The Experts Who Keep Threatened Wildlife In Existence

The veterinary team at ZSL represents one of Britain’s most specialised medical workforces. With five fully trained veterinarians, six veterinary nurses, a pathologist, a pathology technician, a molecular diagnostician and a microbiologist, the charity maintains what most British zoos can replicate: a comprehensive, in-house medical facility. This multidisciplinary approach allows the team to manage the complicated medical requirements of creatures extending from dormice to rhinoceroses. Each specialist brings crucial expertise, whether diagnosing obscure parasitic infections, examining genetic material or conducting complex surgical procedures on animals worth millions to international conservation efforts.

The difficulties these experts encounter are distinctly exceptional. Moving a anaesthetised rhino necessitates meticulous preparation and specialist equipment. Anaesthetising a dormouse demands precise dosing for an animal tipping the scales at mere grams. Providing treatment to a venomous snake requires understanding its behaviour and physiology in ways that scarcely any veterinarians come across. The ZSL group continually needs to innovate, utilising extensive accumulated knowledge whilst adapting their techniques to each animal. Their work goes well past standard examinations; they are stewards of some of the Earth’s endangered species, where a individual creature’s survival can carry profound conservation implications.

From Historic Innovators to Present-day Medical Practice

ZSL’s dedication to animal welfare extends back 200 years. The journals of Charles Spooner, the zoo’s first “medical attendant,” offer some of the first written accounts of veterinary care in Britain. Spooner treated a young lion cub named Nelson affected by mange, dental issues and a serious ulcer on his jaw. Through careful treatment—draining the ulcer and giving daily doses of zinc sulphate—Spooner rescued the cub’s life, establishing a legacy of innovative and compassionate animal medicine that remains in place today.

This longstanding foundation has informed modern ZSL veterinary practice. The principles Spooner pioneered—careful examination, resourceful approaches and unwavering dedication to individual animals—remain central to the team’s approach. Over two centuries, ZSL vets have continually advanced boundaries in veterinary care and animal welfare, disseminating findings and establishing techniques now adopted globally. As the zoo marks its bicentenary, its veterinary team stands as a lasting tribute to two hundred years of groundbreaking achievement in exotic animal medicine.

Precise Surgical Intervention on the Earth’s Rarest Species

Every surgical procedure undertaken at ZSL represents a carefully weighed hazard with far-reaching significant consequences. When a vet performs surgery on an endangered animal, they are not simply caring for a single creature—they are protecting an entire population whose survival may depend on that single life. The team must balance the imperative to intervene with the fundamental risks of anaesthesia, infection and surgical complications. Each choice draws upon by decades of accumulated knowledge, joint investigations with international colleagues, and an deep knowledge of the individual’s clinical background and unique characteristics.

The difficulty escalates dramatically when handling creatures whose bodily composition varies considerably from domestic livestock. A rhino’s circulatory system responds unpredictably to anaesthetic administration. A snake’s metabolism metabolises anaesthetic agents at rates that challenge established procedures. A dormouse’s small frame leaves scarcely any allowance for error in medication dosage. The ZSL veterinary staff has established specialised techniques and surveillance equipment to address these difficulties, often developing novel methods that eventually become common procedure across zoological institutions worldwide.

• Anaesthetising dormice requires precise micrograms of meticulously formulated pharmaceutical solutions.
• King cobras demand secure containment protocols during recuperation following sedation procedures.
• Rhino relocations necessitate expert-level gear and coordinated multi-team operations.
• Dental examinations on carnivores reveal vital signs of general wellbeing.
• Post-operative monitoring involves 24-hour watchful care by experienced veterinary support staff.

The Emotional Connection Between Animal Carers and Animals

Behind every successful medical procedure lies a profound relationship between caregiver and creature. Zookeepers like Tara Humphrey devote extensive time observing their charges, recognising minor changes in behaviour that signal illness or distress. When Bhanu the Asian lion was put under anaesthetic for his ear check, Humphrey took the uncommon chance for tactile contact, cuddling the impressive animal whilst he lay unconscious. These connections go beyond mere emotion; they embody the thorough understanding that enables keepers to deliver vital details to veterinarians, ultimately improving diagnostic accuracy and therapeutic results.

The Practice of Anaesthetizing Massive and Dangerous Wildlife

Administering anaesthesia to the zoo’s most formidable residents represents one of the veterinarians’ most critical responsibilities. Unlike routine procedures at conventional animal hospitals, anaesthetising a lion, rhino, or king cobra demands meticulous planning, specialist equipment, and unwavering composure. The stakes are extraordinarily high: miscalculate the dosage for a 2-tonne rhinoceros and the animal’s heart and circulatory system may fail; administer too little to a venomous snake and the keeper encounters genuine mortal danger. ZSL’s veterinarians have spent decades refining protocols that take into account each animal’s unique physiology, body composition, and metabolic peculiarities.

The process begins long before the syringe penetrates flesh. Veterinarians examine the specific creature’s clinical background, liaise with international specialists, and establish baseline vital signs. They arrange themselves with precision, guaranteeing quick availability to critical apparatus should complications arise. Once the anaesthetic takes effect, continuous monitoring becomes paramount. Pulse, arterial tension, blood oxygen levels, and core heat are monitored intensively. Post-operative phases require comparably careful observation, as animals emerging from sedation can behave unpredictably—as Guardian photographer David Levene found when King Arthur the cobra reared up and spat directly at him, in spite of the protective glass barrier.

Educating the Future of Zoo Veterinarians

The skills needed to care for endangered animals at ZSL doesn’t materialise overnight. Prospective zoo veterinarians undergo years of demanding training, beginning with traditional veterinary qualifications before specialising in exotic and wild animal medicine. ZSL’s established reputation draws talented professionals from throughout the globe, many of whom undertake supervised placements under the charity’s experienced team. This hands-on education proves invaluable; theoretical learning alone cannot equip a vet for the unpredictability of sedating a lion or identifying illness in a at-risk species where every individual matters profoundly to conservation work.

The veterinary team at ZSL actively contributes in career advancement within the zoo sector, disseminating expertise through peer-reviewed articles, industry conferences, and joint research initiatives. Young veterinarians benefit from involvement with diverse cases—from routine health checks to emergency interventions—whilst working alongside specialists in pathology, microbiology, and molecular diagnostics. This cross-functional setting drives advancement in animal healthcare and ensures that junior veterinarians understand the broader context of zoo medicine: balancing immediate animal welfare with long-term conservation goals and contributing to scientific understanding of species preservation.

• Mentorship under expert ZSL veterinarians focusing on care of exotic animals and urgent intervention
• Access to state-of-the-art diagnostic tools and pathology laboratories for practical training
• Engagement in cross-border research initiatives advancing veterinary care standards for zoos
• Exposure to various animal species requiring customised treatment methods and conservation-focused treatment strategies