Cat flu: Broad spectrum polymeric antivirals.

Feline herpesvirus type 1 (FHV-1) and feline calicivirus (FCV) are considered as main causes of feline upper respiratory tract disease and the most common clinical manifestations include rhinotracheitis, conjunctivitis, and nasal/facial ulcerations. While the primary infection is relatively mild, secondary infections pose a threat to young or immunocompromised cats and may result in a fatal outcome. In this study, we made an effort to evaluate antiviral potency of poly(sodium 4-styrenesulfonates) (PSSNa) as potent FHV-1 and FCV inhibitors for topical use. Mechanistic studies showed that PSSNa exhibits a different mechanism of action depending on target species. While PSSNa acts directly on FHV-1 particles blocking their interaction with the host's cell and preventing the infection, the antiviral potency against FCV is based on inhibition at late stages of the viral replication cycle. Altogether, PSSNa polymers are promising drug candidates to be used in the treatment and prevention of the viral upper respiratory tract disease (URTD), regardless of the cause. • Feline herpesvirus type 1 (FHV-1) and feline calicivirus (FCV) are the main causes of cat flu. • Poly(sodium 4-styrenesulfonate) (PSSNa) is non-toxic and inhibits laboratory and clinical isolates of FHV-1 and FCV. • PSSNa shows dual activity: it blocks FHV-1 entry to the cell and, at the same time, it interferes with FCV replication. • PSSNa may be used topically to limit the transmission, milden the symptoms and protect cats from lethal sequelae. [ABSTRACT FROM AUTHOR]