Common Cream Effective in Treating Feline Herpesvirus

Thanks to an international research collaboration, cats with feline herpesvirus type 1 (FHV-1) have a new treatment that is easier for their owners to manage.

Veterinarians at the Koret School of Veterinary Medicine (KSVM) at Hebrew University of Jerusalem and UC Davis have discovered that a common cold sore cream is effective in treating the painful eye infection.

One of the KSVM researchers on the project is Dr. Lionel Sebbag, a former UC Davis ophthalmology resident. Along with several other KSVM faculty members, he collaborated with one of his former mentors at UC Davis, Dr. Sara Thomasy. 

Sebbag and Thomasy designed the study together and collaborated on the grant application to fund the research. A Koret endowment at the CCAH for joint research collaborations between KSVM and UC Davis approved the application and provided the funding.

“It is an immense privilege to be funded by such a wonderful program that fosters collaborations between Koret and UC Davis,” stated Thomasy.

“Based on the strong work by Dr. Thomasy and others at UC Davis showing that oral famciclovir is effective in cats with FHV-1, we thought it made sense to try giving the active drug directly to the eye,” said Sebbag. 

While oral famciclovir is safe and effective, it is difficult for some owners to administer and has limited metabolism in cats. However, the main ingredient in the common cream is penciclovir, the active form of famciclovir.

Sebbag and his team at KSVM applied the cream directly onto the ocular surface of infected cats, similar to an ophthalmic ointment. The results were an overwhelming success. In a retrospective survey, owners reported improvement in their cats—85% stating no side effects and 80% rating the treatment as effective or highly effective. To confirm safety and effectiveness, the researchers conducted additional studies in healthy cats over a month-long period with no adverse reactions.

Thomasy, in collaboration with the SVM Bioanalytical Research Core, followed up with analysis of concentrations of the drug in the patients’ systems to help determine effectiveness and the best timeframes of treatment applications.

This application of topical penciclovir has become the standard treatment for affected cats at KSVM and is now widely used across Israel.

The positive results were published in Research in Veterinary Science, and the data was presented at international veterinary ophthalmology meetings. Sebbag reports that a number of colleagues abroad have since implemented the treatment in their practice.