Feline herpesvirus associated ulcerative and crusting dermatitis has been reported in cats and cheetahs. In this case report, a 3-year-old Abyssinian-mix cat was initially diagnosed via skin biopsy with an eosinophilic granuloma on the muzzle. The lesion did not respond to glucocorticoid or antibiotic therapy. Reevaluation of the specimen revealed intranuclear inclusion bodies, and a presumptive diagnosis of feline herpes dermatitis was made and confirmed via polymerase chain reaction testing of a conjunctival swab. The lesion consisted of a hairless area on the lateral aspect of the muzzle with thickened skin and mild crusting. The cat was treated with recombinant interferon-Ω  at a dose of 1.5 million units/kg. Half the dose was injected perilesionally and intradermally, and the remaining dose was administered subcutaneously. The lesion regressed rapidly as early as 2 days after treatment. The cat was treated again on days 2, 9, 19, 21, and 23. Two months after therapy, the lesion was markedly smaller; after 4 months, the cat had only a small crust, which was removed surgically.

COMMENTARY: Until this case report, there has not been a successful treatment for herpes dermatitis in cats. Currently recombinant interferon-Ω  is manufactured by Virbac (www.virbaccorp.com) under the name Virbagen Omega (rFEIFN) and is used to treat feline leukemia virus. It is not licensed for use in the United States but will soon be registered for use in Canada. It has been used in Europe since 2001 to treat parvovirus infections. In 2004, its use was extended to include cats-for treatment of nonterminal cases of feline leukemia or feline immunodeficiency.

Feline herpes dermatitis treated with interferon omega. Gutzwiller ME, Brachelente C, Taglinger K, et al. VET DERMATOL 18:50-54, 2007.