Effect of topical ophthalmic application of cidofovir on experimentally induced primary ocular feline herpesvirus-1 infection in cats

Am J Vet Res. 2008 Feb;69(2):289-93. doi: 10.2460/ajvr.69.2.289.


Objective: To evaluate the efficacy of twice-daily ophthalmic application of 0.5% cidofovir solution in cats with experimentally induced primary ocular feline herpesvirus-1 (FHV-1) infection.

Animals: Twelve 6-month-old sexually intact male cats.

Procedures: Cats were randomly assigned to either a treatment or control group. Ocular infection with FHV-1 was induced (day 0) in all cats via inoculation of both eyes with 10(4) plaque-forming units of a plaque-purified FHV-1 field strain. Twice daily for 10 days beginning on day 4 after virus inoculation, the treatment group received 1 drop of 0.5% cidofovir in 1% carboxymethylcellulose in both eyes, and the control group received 1 drop of 1% carboxymethylcellulose in both eyes. A standardized scoring method was used to evaluate clinical signs of FHV-1 infection in each cat once daily for 24 days. The amount of ocular viral shedding was assessed by use of a quantitative real-time PCR procedure every 3 days during the study period. Clinical scores and viral quantification were averaged over the pretreatment (days 0 to 3), treatment (days 4 to 14), and posttreatment (days 15 to 24) periods for each cat.

Results: During the treatment period, clinical scores and amount of viral ocular shedding were significantly lower in the treatment group, compared with findings in the control group.

Conclusions and clinical relevance: Twice-daily application of 0.5% cidofovir solution in both eyes significantly decreased the amount of viral shedding and the severity of clinical disease in cats with experimentally induced ocular FHV-1 infection.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Animals
  • Antiviral Agents / administration & dosage*
  • Antiviral Agents / therapeutic use*
  • Cat Diseases / drug therapy*
  • Cat Diseases / virology
  • Cats
  • Cidofovir
  • Conjunctivitis, Viral / drug therapy
  • Conjunctivitis, Viral / veterinary
  • Cytosine / administration & dosage
  • Cytosine / analogs & derivatives*
  • Cytosine / therapeutic use
  • Drug Administration Schedule
  • Herpesviridae Infections / drug therapy
  • Herpesviridae Infections / veterinary*
  • Herpesviridae*
  • Male
  • Organophosphonates / administration & dosage*
  • Organophosphonates / therapeutic use*


  • Antiviral Agents
  • Organophosphonates
  • Cytosine
  • Cidofovir