Feline Herpesvirus: A Persistently Relevant Disease, from Infection to Clinical Management

Feline herpesvirus type 1 (FHV-1) is a widespread pathogen responsible for feline viral rhinotracheitis, a highly contagious disease affecting cats worldwide. This virus primarily targets the upper respiratory tract and ocular tissues, leading to clinical signs such as sneezing, nasal discharge, conjunctivitis, keratitis, and, in severe cases, corneal ulceration. FHV-1 is particularly problematic in young, immunocompromised, or stressed cats, and latent infections can result in recurrent clinical manifestations. The pathogenesis of FHV-1 involves initial viral replication in epithelial cells, followed by latency establishment in the trigeminal ganglia. Reactivation can occur due to stress, immunosuppression, or co-infections, leading to viral shedding and disease recurrence. Diagnosis is based on clinical presentation, supported by molecular techniques such as PCR, which detect viral DNA in ocular or respiratory secretions. Serological tests are less useful due to widespread exposure among the feline population. Management of FHV-1 includes supportive care, antiviral therapy, and immune modulation. Topical and systemic antivirals, such as famciclovir and cidofovir, have shown efficacy in reducing viral replication and alleviating clinical symptoms. Interferon therapy and other immunomodulatory treatments are under investigation to enhance antiviral responses. Lysine supplementation, previously recommended, has shown conflicting results in recent studies. Secondary bacterial infections are common and may require antibiotic therapy. Vaccination plays a crucial role in prevention, though it does not completely eliminate the risk of infection or reactivation. Stress management and maintaining optimal environmental conditions can help reduce recurrence. Ocular complications of FHV-1, including chronic conjunctivitis, symblepharon, corneal sequestrum, and stromal keratitis, pose significant challenges in feline ophthalmology. Despite advances in diagnosis and treatment, FHV-1 remains a significant concern in feline medicine. Understanding its pathogenesis, improving management strategies, and developing more effective preventive measures are essential for minimizing its impact on feline health.