Effects of topical ocular administration of high doses of human recombinant interferon alpha-2b and feline recombinant interferon omega on naturally occurring viral keratoconjunctivitis in cats

Abstract

In cats with naturally occurring viral keratoconjunctivitis, bilateral ocular administration of high doses of FelFN or HulFN twice daily for 14 days did not improve clinical disease or virus shedding, compared with treatment with saline solution.

Interferon-omega: Current status in clinical applications

“…Some alternative subcutaneous and topical protocols, such as oral and intralesional administration, have been suggested [59,60]. Interestingly, no adverse effects were found in cats treated with rFeIFN-ω following mucosal administration [58,61], while subcutaneous administration was accompanied by some mild adverse effects (e.g., fever, lethargy, vomiting, and diarrhea) in some trials [46]. Thus, rFeIFN-ω could become an option for treatment in veterinary clinical practice.…”

Ocular manifestations of feline viral diseases

“…The most recent information indicates that 40 mg/kg three times daily is likely to be effective (Thomasy et al, 2012), although, anecdotally, lower doses and frequencies are reported to be effective by some veterinary clinicians. A recent study of high dose topical recombinant human α2b and feline ω interferon in a group of cats with naturally occurring viral keratoconjunctivitis found no beneficial effect of either interferon compared to placebo (Slack et al, 2013); thus, this treatment cannot be recommended.…”

“…Therapy for cats infected with FCV, an RNA virus, is more difficult than for FHV-1, since the virus is not susceptible to drugs that inhibit DNA synthesis. The use of high dose topical ophthalmic interferon was not successful in reducing the severity of FCV-related ocular surface disease (Slack et al, 2013). Specific anti-viral treatment with phosphorodiamidate morpholino oligomers has been used in FCV outbreaks, reducing viral shedding and hastening clinical recovery (Smith et al, 2008).…”

Pathology in Practice

“…5 If the inflammation is predominately neutrophilic, differential diagnoses include bacterial infection, trauma, and cowpox virus infection. 11 The use of feline interferon-ω as a means of reducing viral shedding and the severity of clinical signs associated with FHV-1 infection has also been tested with mixed results. Although the histologic lesions in the cat of the present report were characteristic of FHV-1-associated dermatitis, PCR assay of fresh or paraffin-embedded tissue is an excellent confirmatory test and can be used in cases in which there is a suspicion of FHV-1-associated ulcerative dermatitis but the histopathologic findings are not diagnostic.…”

“…5 Diagnostic FHV-1 viral inclusion bodies are seen within the intact epithelium but may not be present when samples are collected from only areas of ulceration. [11][12][13] One study 14 examining the efficacy of valacyclovir was similarly unrewarding and actually resulted in toxic effects in the treated cats with early termination of the study for humane reasons. 1 Treatment of FHV-1 infection in cats is challenging and is often limited to supportive care and treatment of secondary infections.…”