Lion herpesvirus

What is it?

Lion herpesvirus is a contagious viral infection affecting large cats, including lions (Panthera leo). It is caused by a herpesvirus related to the virus responsible for upper respiratory infection in domestic cats. This disease primarily affects the upper respiratory tract and eyes. It can occur in lions living in zoos, wildlife reserves, or conservation centers, particularly when several animals are in close contact.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Causes and risk factors

The disease is caused by a feline herpesvirus, a DNA virus belonging to the Herpesviridae family. This virus is related to the one that causes feline viral rhinotracheitis in domestic cats, but strains specific to large cats have also been described. Once infected, an animal may remain a latent carrier of the virus for life, with possible reactivations during periods of stress or immune system weakness.

Young lion cubs, weakened animals, stressed or recently transported individuals are more vulnerable. Close quarters in captivity, in zoos or wildlife centers, promote virus transmission between animals. An immune system already compromised by another disease increases the risk of severe disease.

Transmission

The virus spreads mainly through direct contact between animals, via eye, nasal, or mouth secretions. Contaminated objects and surfaces (food bowls, litter boxes, shared enclosures) can also play a role in transmission, especially in captivity where contact is more frequent.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

Treatment

Treatment is mainly supportive: fluids to combat dehydration, eye care with appropriate products, and sometimes antibiotics to prevent or treat secondary bacterial infection. Specific antivirals may be considered by the veterinarian depending on severity. Rest and stress reduction promote recovery.

Prevention

Possible complications

Possible complications include corneal ulcers that may progress to partial vision loss if untreated, secondary bacterial infections of the respiratory tract, and progression to pneumonia in the most fragile animals, particularly the young.

When to see a veterinarian

Prognosis

The outlook is generally favorable in healthy adults, with recovery in a few weeks with supportive care. It is more guarded in lion cubs or immunocompromised animals, where eye or respiratory complications may result in lasting effects.

Frequently asked questions

References

WOAH — Organisation mondiale de la santé animale (ex-OIE)

MSD Veterinary Manual

Content reviewed by the TunisieVet editorial team · Updated 31 August 2026