Evaluation of compounded cidofovir, famciclovir, and ganciclovir for the treatment of feline herpesvirus ocular surface disease in shelter-housed cats.

Abstract

To assess the efficacy of compounded cidofovir, famciclovir, and ganciclovir for the treatment of feline herpesvirus type 1 (FHV-1) ocular surface disease. 132 shelter-housed cats qPCR positive for FHV-1. A masked placebo-controlled study design was utilized. Animals were enrolled in one of four treatment groups: topical ocular placebo + oral placebo (n=32), compounded cidofovir 0.5% ophthalmic solution + oral placebo (n=32), compounded famciclovir oral solution (90 mg/kg) + topical ocular placebo (n=32), and compounded ganciclovir 0.15% ophthalmic solution + oral placebo (n=36). Cats were treated with each medication twice daily for 7 days and were evaluated on Day 1 and Day 8 using an ocular scoring system, body weight, and qPCR for FHV-1 viral load. Cidofovir significantly decreased viral load from Day 1 to Day 8 compared with placebo (p=.024). Neither famciclovir nor ganciclovir decreased viral load compared with placebo (p=.14, p=.41). There was no significant improvement of ocular scores for any drug group compared with placebo (p=.62). In all groups, 65%-75% of cats improved from Day 1 to Day 8. Juvenile cats had a significant increase in weight gain compared with placebo for cidofovir (p=.025) and ganciclovir (p=.023). All corneal ulcers in placebo animals failed to heal whereas 77% of ulcers in antiviral group animals healed. Topical ophthalmic cidofovir significantly decreased ocular FHV-1 viral shedding and increased weight gain in juvenile cats. Ganciclovir increased weight gain in juvenile cats. Compounded famciclovir demonstrated limited efficacy for the treatment of FHV-1 ocular surface disease in shelter-housed cats.