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 documented a year spent shadowing the charity’s elite veterinary team, recording the remarkable difficulties of treating some of the world’s most dangerous and endangered animals. From anaesthetising a king cobra that reacted to sedation with a toxic discharge to examining an Asiatic lion’s unusually narrow ear canal, the vets, nurses and specialists working across ZSL’s London and Whipsnade zoos navigate medical emergencies that most other medical practitioners ever encounter. With just a small number of British zoos employing their own resident vets, ZSL’s team of five vets, nursing staff of six, a animal pathologist and several specialists constitute a rare breed of medical expertise—one that has established standards in animal care for 200 years.

A Year of Exceptional Clinical Pressures

David Levene’s extended photographic project uncovered the unpredictable nature of zoo veterinary work. On his second visit, the documentarian found himself face-to-face with Bhanu, an Asiatic lion afflicted with chronic recurrent ear infections that had left him with an unusually narrow ear canal. The condition necessitated a general anaesthetic—always a last resort in zoo medicine—so the animal care specialists could conduct a thorough examination. Whilst Bhanu was sedated, the vets took the chance to carry out detailed health assessments, encompassing detailed inspection of his teeth, which are essential for a meat-eater’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 jabbed in the tail,” Levene recalls with wry humour. One bite from the young snake could cause death to an elephant, yet the ZSL team handles such exceptionally perilous patients with practiced care and unwavering professionalism.

• King cobra reacts to anaesthetic with venom-spraying display
• Asiatic lion needs sedation for ear canal examination
• Veterinary team carries out multiple health checks during anaesthesia
• Zoo medicine calls for expertise with exotic and hazardous species

Those Specialists Responsible for Keeping Threatened Wildlife In Existence

The veterinary team at ZSL represents one of Britain’s most specialist medical workforces. With five fully trained veterinarians, six nursing professionals, a pathologist, a pathology technician, a molecular diagnostician and a microbiologist, the charity maintains what most British zoos can provide: a comprehensive, in-house medical facility. This integrated approach permits the team to tackle the complicated medical requirements of creatures spanning from dormice to rhinoceroses. Each specialist brings essential knowledge, whether detecting rare parasitic infections, examining genetic material or conducting complex surgical procedures on animals worth millions to global conservation efforts.

The obstacles these experts encounter are genuinely exceptional. Shifting a unconscious rhino requires thorough planning and advanced apparatus. Anaesthetising a dormouse requires exact pharmaceutical measurement for an animal weighing mere grams. Managing the care of a venomous snake demands grasping its behavioral patterns and physical makeup in ways that relatively few veterinarians ever encounter. The ZSL unit continually needs to innovate, drawing on years of accumulated knowledge whilst adapting their methods to each animal. Their work transcends regular assessments; they are guardians of some of the Earth’s endangered species, where a single animal’s survival can bear significant ecological implications.

From Original Innovators to Modern Medical Practice

ZSL’s focus on animal welfare stretches back 200 years. The journals of Charles Spooner, the zoo’s first “medical attendant,” give some of the first documented records of veterinary medicine in Britain. Spooner treated a lion cub named Nelson suffering from mange, dental issues and a serious ulcer on his jaw. Through careful treatment—opening the ulcer and applying regular zinc sulphate treatments—Spooner rescued the cub’s life, establishing a record of innovative, compassionate animal medicine that continues today.

This historical foundation has influenced modern ZSL veterinary practice. The principles Spooner pioneered—meticulous observation, innovative solutions and unwavering dedication to individual animals—remain core to the team’s approach. Over two centuries, ZSL vets have consistently pushed boundaries in animal wellbeing and health, publishing research and developing techniques now implemented worldwide. As the zoo commemorates its bicentenary, its veterinary team stands as a living testament to two hundred years of innovative leadership in exotic animal medicine.

Precise Surgical Intervention on the Earth’s Rarest Creatures

Every surgical procedure undertaken at ZSL represents a calculated risk with potentially enormous consequences. When a vet performs surgery on an species at risk, they are not simply treating an individual patient—they are safeguarding a species whose continued existence could rely on that single life. The team must balance the imperative to intervene with the inherent dangers of anaesthesia, infection and operative setbacks. Each choice draws upon by decades of accumulated knowledge, collaborative research with overseas specialists, and an deep knowledge of the individual’s clinical background and individual quirks.

The difficulty escalates dramatically when dealing with creatures whose bodily composition differs radically from domestic livestock. A rhino’s cardiovascular system responds unpredictably to sedation. A snake’s metabolic rate breaks down anaesthetic agents at rates that exceed conventional guidelines. A dormouse’s tiny body leaves scarcely any allowance for error in medication dosage. The ZSL veterinary team has developed tailored approaches and surveillance equipment to overcome these obstacles, often establishing innovative techniques that subsequently become standard practice across zoo facilities worldwide.

• Anaesthetising dormice requires accurate micrograms of carefully calculated pharmaceutical solutions.
• King cobras demand secure containment protocols during recuperation following sedation procedures.
• Rhino relocations necessitate specialist equipment and integrated multi-agency operations.
• Dental examinations on carnivores reveal crucial indicators of comprehensive health condition.
• Post-operative monitoring involves continuous surveillance by dedicated veterinary nursing staff.

The Deep Bond Between Animal Carers and Creatures

Behind every effective medical procedure lies a deep relationship between caregiver and creature. Zookeepers like Tara Humphrey spend countless hours observing their animals, identifying minor changes in behaviour that signal illness or discomfort. When Bhanu the Asiatic lion was put under anaesthetic for his ear examination, Humphrey seized the rare opportunity for tactile contact, cuddling the magnificent beast whilst he lay asleep. These bonds go beyond mere emotion; they embody the thorough understanding that enables keepers to provide crucial information to veterinarians, ultimately enhancing accuracy of diagnosis and therapeutic results.

The Practice of Anaesthetising Large and Hazardous Animals

Administering anaesthesia to the zoo’s most formidable residents represents one of the veterinarians’ most essential responsibilities. Unlike routine procedures at conventional animal hospitals, sedating a lion, rhino, or king cobra demands careful preparation, specialist equipment, and nerves of steel. The stakes are extraordinarily high: miscalculate the dosage for a 2-tonne rhinoceros and the animal’s cardiovascular system may collapse; 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 species’ unique physiology, body composition, and metabolic peculiarities.

The procedure begins long before the syringe enters flesh. Veterinarians study the individual animal’s medical history, consult with overseas experts, and establish standard physiological measurements. They arrange themselves with precision, guaranteeing quick availability to emergency equipment should complications arise. Once the sedative begins working, continuous monitoring becomes paramount. Heart rate, arterial tension, oxygen saturation, and body temperature are monitored intensively. Recovery periods require equally vigilant observation, as animals coming out of anaesthesia can act erratically—as Guardian photographer David Levene discovered when King Arthur the cobra reared up and spat directly at him, despite the protective glass barrier.

Educating the Next Generation of Zoo Veterinarians

The expertise needed to care for endangered animals at ZSL doesn’t materialise overnight. Prospective zoo veterinarians complete extended periods of intensive training, starting with traditional veterinary qualifications before specialising in wild and exotic animal medicine. ZSL’s established reputation draws accomplished professionals from throughout the globe, many of whom complete supervised placements under the charity’s seasoned team. This practical education demonstrates as invaluable; theoretical learning alone cannot equip a vet for the variability of anaesthetising a lion or diagnosing illness in a at-risk species where every individual matters greatly to conservation efforts.

The veterinary team at ZSL plays a key role in professional development within the zoo sector, sharing their accumulated knowledge through publications, conferences, and collaborative research projects. Young veterinarians benefit from exposure to diverse cases—from standard wellness examinations to emergency interventions—whilst working alongside specialists in pathology, microbiology, and molecular diagnostics. This multidisciplinary environment fosters innovation in veterinary medicine and ensures that junior veterinarians understand the wider implications of zoo medicine: balancing immediate animal welfare with long-term conservation goals and contributing to scientific understanding of species preservation.

• Training under experienced ZSL veterinarians with expertise in care of exotic animals and emergency procedures
• Access to cutting-edge diagnostic tools and laboratory facilities for hands-on learning
• Engagement in international research collaborations improving zoo veterinary medicine standards
• Experience to various animal species requiring species-specific medical strategies and conservation-focused treatment strategies