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 specialist animal doctors, capturing the extraordinary challenges of caring for some of the world’s rarest and most vulnerable 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 working across ZSL’s London and Whipsnade zoos navigate medical emergencies that most other medical practitioners ever encounter. With only a handful of British zoos employing their own resident vets, ZSL’s team of five vets, nursing staff of six, a animal pathologist and several specialists represent a unique form of veterinary knowledge—one that has established standards in animal care for 200 years.

A Year of Unprecedented Clinical Pressures

David Levene’s extended photographic project uncovered the unpredictable nature of zoo animal medicine. On his second visit, the documentarian encountered 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 final option in zoo medicine—so the animal care specialists could conduct a comprehensive assessment. Whilst Bhanu was under sedation, the vets took the chance to carry out comprehensive health checks, encompassing careful examination of his teeth, which are essential for a carnivore’s wellbeing and survival in captivity.

Perhaps the most dramatic moment came when King Arthur, a young king cobra and the world’s longest venomous snake, was given 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 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 extraordinarily dangerous patients with practiced care and unwavering professionalism.

• King cobra responds to anaesthetic with venomous spitting display
• Asiatic lion needs sedation for ear canal examination
• Veterinary team conducts multiple health checks during anaesthesia
• Zoo medicine calls for expertise with rare and dangerous species

The Professionals Who Keep Endangered Species Thriving

The veterinary staff at ZSL exemplifies one of Britain’s most specialist medical workforces. With five fully qualified 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 full in-house medical facility. This multidisciplinary approach permits the team to manage the complicated medical requirements of creatures extending from dormice to rhinoceroses. Each specialist provides essential knowledge, whether diagnosing obscure parasitic infections, examining genetic material or performing intricate surgical procedures on animals worth millions to global conservation efforts.

The difficulties these professionals deal with are truly exceptional. Relocating a sedated rhino requires thorough planning and specialist equipment. Anaesthetising a dormouse demands precise dosing for an animal weighing mere grams. Managing the care of a venomous snake requires grasping its behavioral patterns and physical makeup in ways that relatively few veterinarians ever encounter. The ZSL group must constantly adapt their methods, utilising extensive accumulated knowledge whilst adapting their approaches to specific creatures. Their work goes well past regular assessments; they are guardians of some of the planet’s most endangered species, where a individual creature’s survival can carry significant ecological implications.

From Historic Pioneers to Contemporary Medicine

ZSL’s focus on animal welfare extends back two centuries. The journals of Charles Spooner, the zoo’s original “medical attendant,” provide some of the first written evidence of veterinary medicine in Britain. Spooner managed a young lion cub named Nelson afflicted with mange infection, dental issues and a life-threatening ulcer on his jaw. Through meticulous care—lancing the ulcer and applying daily doses of zinc sulphate—Spooner preserved the cub’s life, establishing a tradition of innovative, compassionate animal medicine that remains in place today.

This longstanding foundation has influenced modern ZSL veterinary practice. The principles Spooner pioneered—precise scrutiny, 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 health and welfare, disseminating findings and establishing techniques now embraced internationally. As the zoo marks its bicentenary, its veterinary team stands as a living testament to two hundred years of groundbreaking achievement in exotic animal medicine.

Precision Surgery on the Planet’s Rarest Creatures

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 survival may depend on that one individual. The team must weigh the need to act with the fundamental risks of anaesthesia, infection and operative setbacks. Each choice draws upon by decades of accumulated knowledge, joint investigations with overseas specialists, and an intimate understanding of the specific animal’s medical history and unique characteristics.

The difficulty increases substantially when dealing with creatures whose physical structure varies considerably from tame species. A rhino’s cardiovascular system behaves inconsistently to sedative drugs. A snake’s metabolism processes anaesthetic agents at rates that challenge established procedures. A dormouse’s tiny body leaves almost no room for error in drug dosing. The ZSL veterinary staff has created tailored approaches and observation technology to address these difficulties, often establishing innovative techniques that subsequently become established protocol across zoological organisations 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 specialist equipment and coordinated multi-team operations.
• Dental examinations on carnivores reveal crucial indicators of comprehensive health condition.
• Post-operative monitoring involves round-the-clock observation by dedicated veterinary nursing staff.

The Emotional Connection Between Animal Carers and Creatures

Behind every effective medical procedure lies a deep relationship between caregiver and animal. Zookeepers like Tara Humphrey devote extensive time observing their animals, recognising minor changes in behaviour that indicate illness or distress. When Bhanu the Asiatic lion was put under anaesthetic for his ear examination, Humphrey seized the rare opportunity for physical affection, embracing the magnificent beast whilst he lay unconscious. These connections transcend sentimentality; they embody the deep knowledge that enables keepers to deliver vital details to veterinarians, ultimately improving accuracy of diagnosis and treatment outcomes.

The Science of Anaesthetising Large and Hazardous Animals

Administering anaesthesia to the zoo’s most formidable residents represents one of the veterinarians’ most critical responsibilities. Unlike standard operations at traditional veterinary clinics, sedating a lion, rhino, or king cobra demands careful preparation, specialised apparatus, 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; give insufficient medication to a venomous snake and the keeper encounters real risk of death. ZSL’s veterinarians have spent decades refining protocols that account for each animal’s distinctive biological makeup, physical structure, and metabolic characteristics.

The procedure commences well ahead of the syringe enters flesh. Veterinarians study the individual animal’s clinical background, consult with overseas experts, and determine standard physiological measurements. They position themselves strategically, ensuring rapid access to emergency equipment should complications arise. Once the anaesthetic takes effect, constant observation grows essential. Heart rate, arterial tension, blood oxygen levels, and body temperature are monitored intensively. Post-operative phases demand comparably careful observation, as animals emerging from sedation can act erratically—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, beginning with standard veterinary qualifications before focusing in exotic and wild animal medicine. ZSL’s well-regarded reputation attracts accomplished professionals from throughout the globe, many of whom undertake mentored training under the organisation’s experienced team. This direct education demonstrates as invaluable; academic study alone cannot equip a vet for the unpredictability of anaesthetising a lion or identifying illness in a critically endangered species where every individual matters greatly to conservation work.

The veterinary team at ZSL actively contributes in professional development within the zoo sector, sharing their accumulated knowledge through peer-reviewed articles, industry conferences, and joint research initiatives. Young veterinarians benefit from involvement with diverse cases—from standard wellness examinations to urgent clinical procedures—whilst working with specialists in pathology, microbiology, and molecular diagnostics. This multidisciplinary environment drives advancement in animal healthcare 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.

• Guidance with experienced ZSL veterinarians specialising in exotic animal care and emergency response
• Exposure to advanced diagnostic equipment and pathology laboratories for hands-on learning
• Engagement in cross-border research initiatives improving veterinary care standards for zoos
• Familiarity to various animal species requiring species-specific medical strategies and conservation-oriented care approaches