Which equine herpesviruses are associated with punctate keratitis?

• A. EHV-2 and EHV-5
• B. EHV-1 and EHV-4
• C. EHV-3 and EHV-7
• D. EHV-6 and EHV-8

Answer: (A)

Punctate keratitis in horses is most strongly linked to infection of the ocular surface by equine herpesviruses 2 and 5. These gammaherpesviruses frequently involve the corneal epithelium and can produce small, discrete epithelial lesions that appear as punctate keratitis. They are common, can be latent and reactivated in ocular tissues, and often cause only mild conjunctival inflammation alongside the corneal findings.

Other herpesviruses in horses are more typically associated with different disease patterns—respiratory illness, abortion, neurological disease, or genital infections—so they are not classically linked to punctate keratitis. Therefore, the best-supported association for punctate keratitis is with EHV-2 and EHV-5. If a clinician suspects a herpesviral ocular etiology, PCR testing of ocular swabs can help confirm EHV-2 or EHV-5 involvement.