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 captured a year spent shadowing the charity’s specialist animal doctors, recording the remarkable difficulties of treating some of the world’s most dangerous and endangered animals. From anaesthetising a king cobra that responded to anaesthetic with a toxic discharge to examining an Asiatic lion’s unusually narrow ear canal, the vets, nurses and specialists working across ZSL’s facilities in London and Whipsnade navigate medical emergencies that few other professionals ever face. With just a small number of British zoos having their own resident vets, ZSL’s team of five vets, six nurses, a pathologist and several specialists represent a rare breed of medical expertise—one that has pioneered standards in animal care for 200 years.

A Year of Unprecedented Healthcare Difficulties

David Levene’s year-long photo documentation revealed the unpredictability of zoo veterinary work. On his second visit, the documentarian found himself face-to-face with Bhanu, an Asiatic lion suffering from persistent recurring ear infections that had resulted in an unusually narrow ear canal. The condition necessitated a general anaesthetic—always a final option in zoo medicine—so the veterinary team could conduct a comprehensive assessment. Whilst Bhanu was sedated, the vets seized the opportunity to perform detailed health assessments, encompassing careful examination of his teeth, which are absolutely crucial 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 responded 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 cause death to an elephant, yet the ZSL team handles such exceptionally perilous patients with practiced care and unwavering professionalism.

• King cobra displays anaesthetic with venom-spraying display
• Asiatic lion demands sedation for aural examination
• Veterinary team conducts multiple health checks during anaesthesia
• Zoo medicine demands expertise with exotic and hazardous species

The Professionals Who Keep At-Risk Animals In Existence

The veterinary staff at ZSL represents one of Britain’s most specialised 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 few UK zoos can match: a comprehensive on-site medical facility. This multidisciplinary approach enables the team to address the intricate health demands of creatures ranging from dormice to rhinoceroses. Each specialist brings crucial expertise, whether identifying unusual parasitic infections, examining genetic material or performing intricate surgical procedures on animals worth millions to international conservation efforts.

The difficulties these professionals deal with are truly exceptional. Moving a unconscious rhino demands careful planning and advanced apparatus. Anaesthetising a dormouse calls for exact pharmaceutical measurement for an animal tipping the scales at mere grams. Treating a venomous snake necessitates understanding its behavioral patterns and physical makeup in ways that scarcely any veterinarians experience. The ZSL unit must constantly innovate, utilising extensive accumulated knowledge whilst adjusting their approaches to each animal. Their work extends far beyond routine check-ups; they are guardians of some of the planet’s most endangered species, where a lone animal’s survival can carry major preservation implications.

From Historic Pioneers to Contemporary Medicine

ZSL’s commitment to the welfare of animals stretches back two centuries. The journals of Charles Spooner, the zoo’s first “medical attendant,” offer among the earliest written accounts of animal medical care in Britain. Spooner cared for a lion cub named Nelson afflicted with mange infection, dental issues and a serious ulcer on his jaw. Through careful intervention—lancing the ulcer and administering daily doses of zinc sulphate—Spooner preserved the cub’s life, setting a legacy of compassionate and innovative veterinary care that continues today.

This longstanding foundation has informed modern ZSL veterinary practice. The principles Spooner pioneered—careful examination, creative problem-solving and resolute devotion to individual animals—remain fundamental to the team’s approach. Over two centuries, ZSL vets have continually advanced boundaries in animal wellbeing and health, producing research and creating techniques now implemented worldwide. As the zoo commemorates its bicentenary, its veterinary team stands as a enduring monument to two hundred years of innovative leadership in exotic animal medicine.

Precision Surgery on the Planet’s Rarest Animals

Every surgical procedure undertaken at ZSL represents a calculated risk with far-reaching significant consequences. When a veterinarian operates on an endangered animal, they are not simply treating an individual patient—they are protecting an entire population whose continued existence could rely on that one individual. The team must balance the imperative to intervene with the fundamental risks of anaesthesia, infection and operative setbacks. Each choice draws upon by years of gathered knowledge, collaborative research with overseas specialists, and an intimate understanding of the individual’s clinical background and unique characteristics.

The complexity grows significantly when working with creatures whose bodily composition deviates substantially from domesticated animals. A rhino’s cardiovascular system behaves inconsistently to sedative drugs. A snake’s metabolic processes metabolises anaesthetic agents at rates that challenge established procedures. A dormouse’s diminutive physique leaves almost no room for error in medication dosage. The ZSL veterinary team has established bespoke methods and surveillance equipment to overcome these obstacles, often developing novel methods that later become standard practice across zoo facilities worldwide.

• Anaesthetising dormice requires accurate micrograms of meticulously formulated pharmaceutical solutions.
• King cobras demand secure containment protocols during recovery from sedation procedures.
• Rhino relocations necessitate specialised apparatus and integrated multi-agency operations.
• Dental examinations on carnivores reveal key markers of general wellbeing.
• Post-operative monitoring involves 24-hour watchful care by experienced veterinary support staff.

The Emotional Connection Between Keepers and Creatures

Behind every successful medical intervention lies a deep relationship between keeper and animal. Zookeepers like Tara Humphrey spend countless hours observing their animals, recognising subtle behavioural shifts that signal illness or discomfort. When Bhanu the Asian lion was put under anaesthetic for his ear examination, Humphrey took the uncommon chance for physical affection, cuddling the impressive animal whilst he lay asleep. These bonds transcend sentimentality; they embody the thorough understanding that enables keepers to provide crucial information to veterinarians, ultimately improving accuracy of diagnosis and treatment outcomes.

The Art of Anaesthetising Large and Hazardous Animals

Administering anaesthesia to the zoo’s most formidable residents represents one of the veterinary team’s most critical duties. Unlike routine procedures at conventional animal hospitals, anaesthetising a lion, rhino, or king cobra demands careful preparation, specialised apparatus, and unwavering composure. The stakes are exceptionally significant: get the dose wrong for a two-tonne rhino and the animal’s heart and circulatory system may collapse; give insufficient medication to a venomous snake and the keeper encounters real risk of death. ZSL’s veterinarians have devoted years refining protocols that take into account each species’ unique physiology, body composition, and metabolic characteristics.

The procedure begins long before the syringe penetrates flesh. Veterinarians examine the specific creature’s clinical background, consult with overseas experts, and establish standard physiological measurements. They position themselves strategically, ensuring rapid access to emergency equipment in case problems develop. Once the anaesthetic takes effect, continuous monitoring grows essential. Pulse, arterial tension, oxygen saturation, and core heat are tracked relentlessly. Recovery periods demand comparably careful observation, as animals emerging from sedation can behave unpredictably—as Guardian photographer David Levene discovered when King Arthur the cobra rose up and spat straight towards him, in spite of the protective glass barrier.

Training the Future of Zoo Veterinarians

The skills needed to treat endangered animals at ZSL does not emerge overnight. Aspiring zoo veterinarians complete extended periods of demanding training, starting with standard veterinary qualifications before specialising in wild and exotic animal medicine. ZSL’s established reputation attracts accomplished professionals from throughout the globe, many of whom undertake mentored training under the charity’s experienced team. This direct education proves invaluable; textbook knowledge alone cannot prepare a vet for the variability of anaesthetising a lion or identifying illness in a critically endangered species where every individual matters greatly to wildlife conservation.

The veterinary team at ZSL actively contributes in career advancement within the zoo sector, sharing their accumulated knowledge 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 drives advancement in veterinary medicine and ensures that emerging practitioners understand the broader context of zoo medicine: balancing immediate animal welfare with sustained species preservation objectives and contributing to scientific understanding of species preservation.

• Training from experienced ZSL veterinarians with expertise in care of exotic animals and urgent intervention
• Exposure to state-of-the-art diagnostic equipment and laboratory facilities for hands-on learning
• Participation in cross-border research initiatives advancing zoo veterinary medicine standards
• Familiarity to a wide range of species demanding species-specific medical strategies and conservation-oriented care approaches