Dendritic ulcers in the cat: what they indicate
2-year-old cat adopted from a shelter, with blepharospasm and epiphora in the left eye for 3 days and no respiratory signs. After fluorescein application, several very fine, linear, branching superficial ulcers are seen.
What does this staining pattern indicate?
chevron_right Show answer and explanation
A. Feline herpesvirus-1 infection, through the direct cytopathic effect of the virus on the corneal epithelium
Correct. Dendritic ulcers are considered pathognomonic of FHV-1. They may progress to larger geographic ulcers. They are usually due to recrudescence of latent virus, even without respiratory signs.
B. Chlamydia felis infection
Chlamydia felis causes conjunctivitis with marked chemosis, but it does not usually involve the cornea or cause ulcers.
C. Feline calicivirus infection
Calicivirus causes oral ulcers and mild conjunctivitis, but not dendritic ulcerative keratitis.
D. Linear scratches from trauma by another cat's claws
A scratch produces one or a few wider, non-branching linear ulcers. The fine, branching pattern is characteristic of the virus.
lightbulb Key takeaway
Dendritic ulcers are fine and best seen with fluorescein (or rose bengal) under cobalt blue light. If you see them, you do not need PCR to treat as FHV-1, and avoid topical corticosteroids. A negative PCR does not rule out herpesvirus.
Test yourself with 10 random questions
Ophthalmology · 100 questions, a different test every time
Related questions
Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.