Kris Bruskiewicz, DVM, DACVIM Veterinary Medical Specialists (Concord)

Human intravenous immunoglobulin (hIVIG) has been investigated in numerous veterinary studies as a potential adjunct therapy for treatment of a variety of immune-mediated disorders in dogs and cats, including immune-mediated hemolytic anemia, immune-mediated thrombocytopenia, pure red cell aplasia, severe cutaneous drug reactions and pemphigus. hIVIG is a sterile immunoglobulin preparation that contains mainly IgG and smaller amounts of IgM and IgA. This product works by blocking Fc receptors on mononuclear phagocytic cells.

hIVIG is administered intravenously typically over a 6-12 hour period. Dogs are usually pre-treated with diphenhydramine. An optimal dose has not been established for veterinary patients. In previous reports, dose ranged from 0.25-2.2 gm/kg. The antigenicity of this product in dogs is not known. Side-effects in dogs are very uncommon.

A recent study published in the Journal of Veterinary Internal Medicine (September/October 2009) compared dogs with primary immune-mediated thrombocytopenia treated with hIVIG vs. placebo. All dogs in the study were treated with doxycycline and prednisone. Within 24 hours of hospitalization, dogs were randomized to receive either a single infusion of hIVIG (0.5 gm/kg) or placebo (0.9% saline). The results of this study showed that treatment with hIVIG resulted in a significant reduction in platelet count recovery time and duration of hospitalization; these findings were similar to those of previously published report.

The major disadvantage to treatment with hIVIG is cost. A 5 gram vial costs approximately $600. Even at a conservative dose of 0.5 gm/kg, the cost to treat a 30kg dog could be prohibitive for many clients.

Despite the cost, hIVIG should be strongly considered a first line treatment in dogs with IMHA or ITP, especially if they have severe anemia/ agglutination or are actively bleeding. If you have any questions about the use of hIVIG in one of your patients, please call any of the VMS internists to discuss this product further.