Which viral infection is classically associated with feline ocular disease?

Feline herpesvirus is notably associated with ocular disease in cats, particularly leading to conditions such as conjunctivitis and keratitis. This viral infection can cause significant inflammation of the cornea and conjunctival tissues, leading to symptoms such as excessive tearing, discharge, squinting, and redness of the eye.

Feline herpesvirus is part of a group of viruses that can lead to upper respiratory infections, and it is especially known for causing conjunctivitis in young kittens and domesticated cats. The virus's ability to cause epithelial cell lysis and resultant inflammation plays a critical role in ocular symptoms.

In comparison, while feline calicivirus can also contribute to upper respiratory diseases, its ocular manifestations are not as prominent as those caused by feline herpesvirus. Feline panleukopenia primarily impacts the gastrointestinal system and immune status but is not known for causing eye disease. Feline immunodeficiency virus primarily affects the immune system and does not directly cause specific ocular diseases, though it can predispose a cat to secondary infections.

Thus, the connection of feline herpesvirus with classic ocular diseases in cats is well established, highlighting it as a primary viral agent in feline ophthalmology.