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 following the charity’s elite veterinary team, capturing 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 venomous spray to examining an Asiatic lion’s distinctly constricted ear canal, the vets, nurses and specialists working across ZSL’s London and Whipsnade zoos navigate medical emergencies that few other professionals ever face. With just a small number of British zoos having their own resident vets, ZSL’s five-strong veterinary team, six nurses, a animal pathologist and multiple specialist experts represent a unique form of veterinary knowledge—one that has established standards in animal care for 200 years.

A Year of Unprecedented Healthcare Difficulties

David Levene’s year-long photo documentation uncovered the unpredictable nature of zoo animal medicine. On his second day, the documentarian encountered Bhanu, an Asiatic lion suffering from chronic recurrent ear infections that had left him with an unusually narrow ear canal. The condition required a general anaesthetic—always a final option 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 comprehensive health checks, encompassing detailed inspection of his teeth, which are essential for a meat-eater’s survival and wellbeing in captivity.

Perhaps the most striking 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 prove fatal 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 needs sedation for ear canal examination
• Veterinary team carries out several health assessments during anaesthesia
• Zoo medicine calls for expertise with rare and dangerous species

Those Specialists That Maintain At-Risk Animals Thriving

The veterinary staff at ZSL exemplifies one of Britain’s most highly specialised workforces. With five certified veterinarians, six nursing staff, a pathologist, a pathology technician, a molecular diagnostician and a microbiologist, the charity operates what few British zoos can provide: a comprehensive, in-house medical facility. This multidisciplinary approach enables the team to tackle the complicated medical requirements of creatures spanning from dormice to rhinoceroses. Each specialist brings vital skills, whether detecting rare parasitic infections, examining genetic material or performing intricate surgical procedures on animals worth millions to international conservation efforts.

The challenges these professionals face are distinctly exceptional. Relocating a anaesthetised rhino requires meticulous preparation and specialist equipment. Sedating a dormouse calls for accurate medication levels for an animal weighing mere grams. Managing the care of a venomous snake demands comprehending its behaviour and physiology in ways that few veterinarians experience. The ZSL unit continually needs to innovate, drawing on years of accumulated knowledge whilst adapting their methods to specific creatures. Their work goes well past regular assessments; they are guardians of some of the world’s most endangered species, where a individual creature’s survival can carry major preservation implications.

From Early Innovators to Present-day Healthcare

ZSL’s commitment to the welfare of animals stretches back two centuries. The journals of Charles Spooner, the zoo’s original “medical attendant,” give some of the first documented records of veterinary medicine in Britain. Spooner cared for a young cub named Nelson suffering from mange, teething troubles and a life-threatening ulcer on his jaw. Through careful intervention—opening the ulcer and giving regular zinc sulphate treatments—Spooner saved the cub’s life, establishing a record of innovative and compassionate animal medicine that remains in place today.

This longstanding foundation has influenced modern ZSL veterinary practice. The principles Spooner pioneered—careful examination, resourceful approaches and steadfast commitment to individual animals—remain fundamental to the team’s approach. Over two centuries, ZSL vets have regularly extended boundaries in animal wellbeing and health, publishing research and developing techniques now embraced internationally. 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 Species

Every surgical operation performed at ZSL represents a carefully weighed hazard with far-reaching significant consequences. When a veterinarian operates on an species at risk, they are not simply caring for a single creature—they are safeguarding a species whose continued existence could rely on that one individual. The team must weigh the need to act 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 escalates dramatically when working with creatures whose anatomy deviates substantially from domestic livestock. A rhino’s circulatory system behaves inconsistently to anaesthetic administration. A snake’s metabolism metabolises anaesthetic agents at rates that challenge established procedures. A dormouse’s diminutive physique leaves virtually no margin for error in drug dosing. The ZSL veterinary staff has developed bespoke methods and observation technology to address these difficulties, often establishing innovative techniques that eventually become standard practice across zoological organisations worldwide.

• Anaesthetising dormice requires precise micrograms of meticulously formulated pharmaceutical solutions.
• King cobras demand robust enclosure protocols during recovery from sedation procedures.
• Rhino relocations necessitate specialist equipment and integrated multi-agency operations.
• Dental examinations on carnivores reveal crucial indicators of overall health status.
• Post-operative monitoring involves round-the-clock observation by experienced veterinary support staff.

The Affectionate Relationship Between Animal Carers and Animals

Behind every effective medical intervention lies a profound relationship between keeper and animal. Zookeepers like Tara Humphrey devote extensive time observing their charges, recognising minor changes in behaviour that indicate illness or discomfort. When Bhanu the Asiatic lion was put under anaesthetic for his ear check, 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 deep knowledge that enables keepers to provide crucial information to veterinarians, ultimately enhancing accuracy of diagnosis and therapeutic results.

The Art of Anaesthetising Massive and Dangerous Wildlife

Administering anaesthesia to the zoo’s most formidable residents represents one of the veterinarians’ most essential responsibilities. Unlike standard operations at conventional animal hospitals, anaesthetising a lion, rhino, or king cobra demands careful preparation, specialist equipment, and unwavering composure. The stakes are extraordinarily high: get the dose wrong for a two-tonne rhino and the animal’s heart and circulatory system may fail; administer too little to a venomous snake and the keeper encounters real risk of death. ZSL’s veterinarians have devoted years developing procedures that take into account each species’ distinctive biological makeup, body composition, and metabolic peculiarities.

The process commences well ahead of the syringe enters flesh. Veterinarians examine the individual animal’s medical history, consult with overseas experts, and establish standard physiological measurements. They position themselves strategically, ensuring rapid access to emergency equipment should complications arise. Once the anaesthetic takes effect, continuous monitoring grows essential. Pulse, arterial tension, blood oxygen levels, and body temperature are tracked relentlessly. Recovery periods require 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 directly at him, despite the protective glass barrier.

Training the Future of Zoo Veterinarians

The specialised knowledge needed to care for threatened animals at ZSL doesn’t materialise overnight. Prospective zoo veterinarians undergo years of rigorous training, starting with traditional veterinary qualifications before focusing in exotic and wild animal medicine. ZSL’s well-regarded reputation draws accomplished professionals from throughout the globe, many of whom complete apprenticeships and mentorships under the charity’s experienced team. This direct education demonstrates as invaluable; theoretical learning alone cannot equip a vet for the uncertainty of anaesthetising a lion or identifying illness in a severely threatened species where each animal matters profoundly to conservation work.

The veterinary team at ZSL plays a key role in professional development within the zoo sector, disseminating expertise through publications, conferences, and collaborative research projects. Young veterinarians gain valuable experience through exposure to diverse cases—from standard wellness examinations to urgent clinical procedures—whilst working with 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: reconciling immediate animal welfare with sustained species preservation objectives and contributing to scientific understanding of species preservation.

• Guidance with experienced ZSL veterinarians specialising in care of exotic animals and emergency procedures
• Access to state-of-the-art diagnostic tools and laboratory facilities for hands-on learning
• Engagement in international research collaborations enhancing standards in zoo veterinary medicine
• Experience to various animal species needing tailored medical approaches and conservation-focused treatment strategies