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Interferon Alpha-2B for Veterinary Use

by Barbara Forney, VMD

Basic Information

Interferons are naturally produced cytokines, which are synthesized and secreted in response to viral infection. As a part of the body's natural immune response, they signal other cells in the body that viral infection has occurred, leading to an "antiviral state" and the inhibition of viral replication. The underlying mechanism behind the antineoplastic properties of interferon is not as well understood but is probably similar to the antiviral mechanism. It has been shown in humans that interferon alpha inhibits the release of granule proteins from eosinophils. Interferon from one species has been shown to have activity in other species.

Cats and Dogs

Human interferon alpha is used in cats to treat FeLV, FIV, FIP, FHV-1 and a variety of dermatologic conditions. Studies support the use of oral human-interferon in cats for its immunomodulatory properties. Work in 2006 with FIV affected cats showed that the published low dose oral protocol improved both clinical signs and survival times, although there was no decrease in viral load. Many clinicians also use the low dose oral protocol to treat cats with FeLV and FIP with the goal of improving clinical signs and quality of life.

Dermatologic uses for oral interferon alpha in cats include indolent ulcers, idiopathic facial dermatitis, dermatitis secondary to FHV infection, atopic disease and mycoses fungoides with paraneoplastic eosinophilia. Interferon alpha also is used in dogs for a number of dermatologic conditions including canine papilloma virus and recurrent pyoderma.

At one time it was thought that oral interferon therapy was ineffective due to degradation of the interferon by proteolytic enzymes of the stomach. Recent work supports the concept that interferon is absorbed orally and that oro-mucosal exposure causes stimulation of the oropharyngeal immune system. Oral interferon therapy is regarded primarily as "immunomodulatory," whereas parenteral therapy with higher doses is thought to be more "antiviral."

Interferon Alpha-2B Side Effects

Cats: Side effects due to low dose oral protocols are rare. Parenteral treatment carries a higher incidence of side effects, particularly malaise and flu like symptoms and less commonly fever or allergic reactions. Bone marrow suppression has been reported in humans.


  • Cats will develop antibodies to parenteral human interferon alpha after three to seven weeks, limiting its useful treatment time span.
  • Animals with autoimmune disease, severe cardiac or pulmonary disease, diabetes, Herpes infection, underlying CNS disease or drug allergy may be at increased risk for complication.

Drug Interactions

Interferon alpha will have an additive antiviral response when combined with the antiviral drugs zidovudine (AZT) and acyclovir. Increased toxicity may occur when interferon alpha is used with vidarabine.


No information was found in the literature.

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Therapeutic Class

Cats and Dogs

May Be Prescribed by Veterinarians for:
Antiviral, anti-neoplastic, immunomodulator.

FDA Status
Interferon Alpha-2B is commercially available as an injection 6000000u/ml, 10000000u/ml, 18000000u/ml, 50000000u/ml.

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About the Author

Barbara Forney, VMD

Dr. Barbara Forney is a veterinary practitioner in Chester County, Pennsylvania. She has a master's degree in animal science from the University of Delaware and graduated from the University of Pennsylvania School of Veterinary Medicine in 1982.

She began to develop her interest in client education and medical writing in 1997. Recent publications include portions of The Pill Book Guide to Medication for Your Dog and Cat, and most recently Understanding Equine Medications published by the Bloodhorse.

Dr. Forney is an FEI veterinarian and an active member of the AAEP, AVMA, and AMWA.

The information contained on this site is general in nature and is intended for use as an informational aid. It does not cover all possible uses, actions, precautions, side effects, or interactions of the products shown, nor is the information intended as medical advice or diagnosis for individual health problems or for making an evaluation as to the risks and benefits of using a particular product. You should consult your doctor about diagnosis and treatment of any health problems. Information and statements have not been evaluated by the Food and Drug Administration ("FDA"), nor has the FDA approved the products to diagnose, cure or prevent disease.

Wedgewood Pharmacy compounded veterinary preparations are not intended for use in food and food-producing animals.