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

As the Zoological Society of London celebrates 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 sedating a king cobra that responded to anaesthetic with a venomous spray to assessing an Asiatic lion’s distinctly constricted ear canal, the vets, nurses and specialists employed at ZSL’s facilities in London and Whipsnade manage critical situations that few other professionals ever encounter. With just a small number of British zoos having their own resident vets, ZSL’s team of five vets, six nurses, a animal pathologist and several specialists represent a unique form of veterinary knowledge—one that has established standards in animal care for two centuries.

A Year of Unprecedented Healthcare Difficulties

David Levene’s extended photographic project revealed the unpredictable nature of zoo veterinary work. On his second day, the photographer found himself face-to-face with Bhanu, an Asiatic lion afflicted with chronic recurrent ear infections that had resulted in an unusually narrow ear canal. The condition necessitated a full anaesthetic—always a final option in zoo medicine—so the animal care specialists could conduct a thorough examination. Whilst Bhanu was under sedation, the vets seized the opportunity to carry out detailed health assessments, including detailed inspection of his teeth, which are essential for a carnivore’s survival and wellbeing 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 responds to anaesthetic with venom-spraying display
• Asiatic lion demands sedation for aural examination
• Veterinary team performs multiple health checks during anaesthesia
• Zoo medicine demands expertise with rare and dangerous species

Those Specialists Responsible for Keeping At-Risk Animals In Existence

The veterinary team at ZSL represents one of Britain’s most specialist medical workforces. With five certified veterinarians, six nursing professionals, a pathologist, a pathology technician, a molecular diagnostician and a microbiologist, the charity runs what few UK zoos can provide: a comprehensive, in-house medical facility. This integrated approach allows the team to tackle the complex health needs of creatures extending from dormice to rhinoceroses. Each specialist brings essential knowledge, whether detecting rare parasitic infections, examining genetic material or executing sophisticated surgical procedures on animals worth millions to worldwide conservation efforts.

The challenges these specialists deal with are genuinely exceptional. Moving a anaesthetised rhino necessitates thorough planning and advanced apparatus. Anaesthetising a dormouse demands accurate medication levels for an animal weighing mere grams. Providing treatment to a venomous snake requires understanding its behavioral patterns and physical makeup in ways that few veterinarians ever encounter. The ZSL group continually needs to adapt their methods, utilising years of accumulated knowledge whilst modifying their approaches to each animal. Their work transcends regular assessments; they are stewards of some of the world’s most endangered species, where a single animal’s survival can bear major preservation implications.

From Historic Innovators to Modern Medical Practice

ZSL’s focus on animal welfare extends back two centuries. The journals of Charles Spooner, the zoo’s original “medical attendant,” give among the earliest written accounts of veterinary care in Britain. Spooner cared for a lion cub named Nelson suffering from mange, teething troubles and a potentially fatal ulcer on his jaw. Through careful treatment—opening the ulcer and applying daily doses of zinc sulphate—Spooner rescued the cub’s life, creating a tradition of innovative and compassionate animal medicine that persists today.

This longstanding foundation has influenced modern ZSL veterinary practice. The principles Spooner pioneered—meticulous observation, innovative solutions 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, publishing research and developing techniques now implemented worldwide. As the zoo celebrates its bicentenary, its veterinary team stands as a enduring monument to two hundred years of groundbreaking achievement in exotic animal medicine.

Precise Surgical Intervention on the Planet’s Rarest Animals

Every surgical operation performed 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 surgical complications. Each decision is informed by decades of accumulated knowledge, joint investigations with international colleagues, and an intimate understanding of the individual’s clinical background and individual quirks.

The difficulty increases substantially when dealing with creatures whose bodily composition varies considerably from tame species. A rhino’s cardiovascular system reacts unpredictably to anaesthetic administration. A snake’s metabolism processes anaesthetic agents at rates that challenge established procedures. A dormouse’s small frame leaves virtually no margin for error in medication dosage. The ZSL veterinary staff has established specialised techniques and surveillance equipment to navigate these challenges, often developing novel methods that eventually become common procedure across zoological institutions worldwide.

• Anaesthetising dormice requires accurate micrograms of carefully calculated pharmaceutical solutions.
• King cobras demand safe housing protocols during recovery from sedation procedures.
• Rhino relocations necessitate specialist equipment and collaborative multi-department operations.
• Dental examinations on carnivores reveal crucial indicators of comprehensive health condition.
• Post-operative monitoring involves 24-hour watchful care by specialist animal care staff.

The Deep Bond Between Animal Carers and Animals

Behind every effective medical procedure lies a deep relationship between caregiver and animal. Zookeepers like Tara Humphrey spend countless hours observing their charges, recognising subtle behavioural shifts that signal illness or discomfort. When Bhanu the Asian lion was anaesthetised for his ear check, Humphrey seized the rare opportunity for tactile contact, cuddling the magnificent beast whilst he lay asleep. These connections transcend sentimentality; they represent the thorough understanding that allows keepers to deliver vital details to veterinarians, ultimately enhancing accuracy of diagnosis and therapeutic results.

The Practice of Anaesthetizing Big and Potentially Dangerous Creatures

Administering anaesthesia to the zoo’s most formidable residents represents one of the veterinarians’ most critical responsibilities. Unlike standard operations at traditional veterinary clinics, anaesthetising a lion, rhino, or king cobra demands meticulous planning, specialist equipment, and unwavering composure. The stakes are exceptionally significant: miscalculate the dosage for a two-tonne rhino and the animal’s heart and circulatory system may collapse; administer too little to a venomous snake and the keeper encounters real risk of death. ZSL’s veterinarians have spent decades developing procedures that account for each animal’s unique physiology, body composition, and metabolic characteristics.

The process commences well ahead of the syringe penetrates flesh. Veterinarians examine the individual animal’s clinical background, consult with international specialists, and determine baseline vital signs. They position themselves strategically, guaranteeing quick availability to critical apparatus should complications arise. Once the anaesthetic takes effect, constant observation grows essential. Heart rate, arterial tension, oxygen saturation, and core heat are tracked relentlessly. Post-operative phases demand equally vigilant observation, as animals coming out of anaesthesia can behave unpredictably—as Guardian photographer David Levene discovered when King Arthur the cobra rose up and spat straight towards him, despite the protective glass barrier.

Educating the Future of Zoo Veterinarians

The skills required to care for endangered animals at ZSL doesn’t materialise overnight. Prospective zoo veterinarians undergo extended periods of demanding training, starting with standard veterinary qualifications before specialising in wild and exotic animal medicine. ZSL’s established reputation draws skilled professionals from throughout the globe, many of whom undertake apprenticeships and mentorships under the charity’s experienced team. This hands-on education proves invaluable; textbook knowledge alone cannot equip a vet for the uncertainty of sedating a lion or identifying illness in a severely threatened species where each animal matters greatly to conservation work.

The veterinary team at ZSL plays a key role in career advancement within the zoo sector, disseminating expertise through peer-reviewed articles, industry conferences, and joint research initiatives. Young veterinarians gain valuable experience through exposure to diverse cases—from standard wellness examinations to urgent clinical procedures—whilst working alongside specialists in pathology, microbiology, and molecular diagnostics. This multidisciplinary environment fosters innovation in veterinary medicine and ensures that emerging practitioners understand the wider implications of zoo medicine: reconciling immediate creature wellbeing with sustained species preservation objectives and advancing scientific understanding of species preservation.

• Mentorship with experienced ZSL veterinarians specialising in exotic animal care and urgent intervention
• Access to cutting-edge diagnostic tools and laboratory facilities for practical training
• Participation in collaborative research projects advancing veterinary care standards for zoos
• Familiarity to various animal species needing tailored medical approaches and treatment approaches centred on conservation