Use of oromucosally administered interferon-alpha in the prevention and treatment of animal diseases.

Interferon-alpha (IFN-alpha) is well known as a clinically effective antiviral and antineoplastic therapeutic agent. It has also been shown to have immunoregulatory properties. IFN-alpha stimulates a cell-mediated innate immune response and then participates in the transition of the initial host innate response to an effective adaptive immune response. IFN-alpha is produced in small quantities in nasal secretions during viral infections, prompting many authors to suggest that low-dose oromucosal administration of IFN-alpha effectively mimics nature. Moreover, the injectable high-dose interferon therapy currently approved for various human disorders causes numerous side effects. By contrast, oromucosal administration of IFN-alpha is not associated with toxic effects. Another distinct advantage is ease of administration: the IFN can be dissolved in drinking water or administered by nebulization to the oral or nasal cavity. This review describes the current state of knowledge concerning orally administered IFN-alpha, of both human and animal origin, as a prophylactic or therapeutic agent in veterinary medicine. We present the effects of IFN-alpha in such animals as cattle, pigs, horses, cats, dogs and chickens, and attempt to explain its mechanism of action following oromucosal administration. It is hoped that this review of the medical literature on the use of IFN-alpha in animals will give practitioners a better understanding of the challenges and benefits of using this interesting cytokine in clinical practice.