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 caring for some of the world’s most dangerous and endangered animals. From anaesthetising a king cobra that responded to anaesthetic with a venomous spray to examining an Asiatic lion’s distinctly constricted ear canal, the vets, nurses and specialists working across ZSL’s facilities in London and Whipsnade manage medical emergencies that most other medical practitioners ever encounter. With only a handful of British zoos having their own in-house veterinarians, ZSL’s team of five vets, nursing staff of six, a pathologist and multiple specialist experts constitute a unique form of veterinary knowledge—one that has pioneered standards in animal care for 200 years.

A Year of Unprecedented Clinical Pressures

David Levene’s year-long photographic project uncovered the unpredictability of zoo veterinary work. On his second day, the photographer found himself face-to-face with Bhanu, an Asiatic lion suffering from persistent recurring ear infections that had resulted in an exceptionally constricted ear canal. The condition required a general anaesthetic—always a final option in zoo medicine—so the veterinary team could conduct a comprehensive assessment. Whilst Bhanu was under sedation, the vets took the chance to perform detailed health assessments, including detailed inspection of his teeth, which are absolutely crucial for a meat-eater’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 reacts to anaesthetic with venomous spitting display
• Asiatic lion needs sedation for ear canal examination
• Veterinary team carries out several health assessments during anaesthesia
• Zoo medicine requires expertise with exotic and hazardous species

The Professionals Responsible for Keeping Threatened Wildlife Thriving

The veterinary team at ZSL exemplifies 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 few British zoos can match: a comprehensive on-site medical facility. This multidisciplinary approach enables the team to address the complicated medical requirements of creatures spanning from dormice to rhinoceroses. Each specialist contributes vital skills, whether detecting rare parasitic infections, examining genetic material or executing sophisticated surgical procedures on animals worth millions to international conservation efforts.

The difficulties these specialists face are distinctly uncommon. Moving a sedated rhino necessitates thorough planning and specialised tools. Sedating a dormouse calls for exact pharmaceutical measurement for an animal tipping the scales at mere grams. Managing the care of a venomous snake requires comprehending its behavioral patterns and physical makeup in ways that few veterinarians ever encounter. The ZSL unit has to regularly develop new approaches, leveraging years of accumulated knowledge whilst adapting their methods to specific creatures. Their work transcends routine check-ups; they are stewards of some of the planet’s most endangered species, where a individual creature’s survival can hold major preservation implications.

From Historic Founders to Modern Medical Practice

ZSL’s commitment to the welfare of animals dates back two centuries. The journals of Charles Spooner, the zoo’s first “medical attendant,” provide some of the first documented records of veterinary medicine in Britain. Spooner treated a lion cub named Nelson suffering from mange, teething problems and a serious ulcer on his lower jaw. Through meticulous care—lancing the ulcer and administering daily zinc sulphate solutions—Spooner saved the cub’s life, establishing a tradition of innovative, compassionate animal medicine that remains in place today.

This longstanding foundation has shaped modern ZSL veterinary practice. The principles Spooner pioneered—careful examination, creative problem-solving and unwavering dedication to individual animals—remain core to the team’s approach. Over two centuries, ZSL vets have regularly extended boundaries in animal wellbeing and health, disseminating findings and establishing techniques now implemented worldwide. As the zoo marks its bicentenary, its veterinary team stands as a living testament to two hundred years of pioneering excellence in exotic animal medicine.

Surgical Precision on the Earth’s Rarest Creatures

Every surgical procedure undertaken at ZSL represents a calculated risk with far-reaching significant consequences. When a vet performs surgery on an species at risk, they are not simply caring for a single creature—they are safeguarding a species whose survival may depend on that single life. The team must weigh the need to act with the inherent dangers of anaesthesia, infection and surgical complications. Each decision is informed by years of gathered knowledge, joint investigations with overseas specialists, and an intimate understanding of the specific animal’s medical history and individual quirks.

The difficulty escalates dramatically when handling creatures whose bodily composition differs radically from tame species. A rhino’s circulatory system reacts unpredictably to anaesthetic administration. A snake’s metabolism processes anaesthetic agents at rates that defy standard protocols. A dormouse’s diminutive physique leaves virtually no margin for error in pharmaceutical administration. The ZSL veterinary experts has developed tailored approaches and surveillance equipment to navigate these challenges, often developing novel methods that subsequently become standard practice across zoo facilities worldwide.

• Anaesthetising dormice requires exact micrograms of carefully calculated pharmaceutical solutions.
• King cobras demand robust enclosure protocols during recuperation following sedation procedures.
• Rhino relocations necessitate expert-level gear and coordinated multi-team operations.
• Dental examinations on carnivores reveal crucial indicators of general wellbeing.
• Post-operative monitoring involves round-the-clock observation by dedicated veterinary nursing staff.

The Deep Bond Between Animal Carers and Animals

Behind every effective medical procedure lies a profound relationship between caregiver and animal. Zookeepers like Tara Humphrey spend countless hours observing their charges, recognising minor changes in behaviour that indicate illness or discomfort. When Bhanu the Asiatic lion was anaesthetised for his ear check, Humphrey took the uncommon chance for physical affection, embracing the magnificent beast whilst he lay asleep. These connections go beyond mere emotion; they represent the thorough understanding that allows keepers to deliver vital details to veterinarians, ultimately enhancing accuracy of diagnosis and therapeutic results.

The Art of Anaesthetizing Big and Potentially Dangerous Wildlife

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 meticulous planning, specialised apparatus, and unwavering composure. The stakes are exceptionally significant: miscalculate the dosage for a 2-tonne rhinoceros and the animal’s heart and circulatory system may fail; give insufficient medication to a venomous snake and the keeper faces real risk of death. ZSL’s veterinarians have spent decades refining protocols that account for each animal’s distinctive biological makeup, body composition, and metabolic peculiarities.

The procedure commences well ahead of the syringe enters flesh. Veterinarians examine the individual animal’s clinical background, liaise with overseas experts, and determine standard physiological measurements. They arrange themselves with precision, guaranteeing rapid access to critical apparatus should complications arise. Once the sedative begins working, continuous monitoring grows essential. Heart rate, arterial tension, oxygen saturation, and body temperature are tracked relentlessly. Post-operative phases demand equally vigilant observation, as animals emerging from sedation can act erratically—as Guardian photographer David Levene found when King Arthur the cobra reared up and spat straight towards him, despite the protective glass barrier.

Educating the Future of Zoo Veterinarians

The specialised knowledge required to care for threatened animals at ZSL does not emerge overnight. Aspiring zoo veterinarians complete extended periods of intensive training, starting with traditional veterinary qualifications before specialising in exotic and wild animal medicine. ZSL’s well-regarded reputation attracts skilled professionals from across the globe, many of whom undertake supervised placements under the charity’s seasoned team. This practical education proves to be invaluable; theoretical learning alone cannot equip a vet for the variability of sedating a lion or diagnosing illness in a critically endangered species where every individual matters greatly to conservation work.

The veterinary team at ZSL plays a key role 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 exposure to diverse cases—from routine health checks to emergency interventions—whilst working alongside specialists in pathology, microbiology, and molecular diagnostics. This multidisciplinary environment fosters innovation in animal healthcare and ensures that junior veterinarians understand the broader context of zoo medicine: balancing immediate creature wellbeing with sustained species preservation objectives and contributing to scientific understanding of species preservation.

• Mentorship under seasoned ZSL veterinarians with expertise in care of exotic animals and emergency procedures
• Exposure to advanced diagnostic equipment and laboratory facilities for hands-on learning
• Participation in international research collaborations enhancing veterinary care standards for zoos
• Familiarity to a wide range of species needing species-specific medical strategies and conservation-oriented care approaches