Preparation and evaluation of homologous IgG on canine parvovirus

Canine parvovirus, an important and highly pathogenic agent for puppies, is distributed worldwide. Despite the various vaccines being available, it is not easily prevented. Immunoglobulin therapy has been attempted as a supportive approach to cure affected puppies.

In order to achieve a homologous immunoglobulin G (IgG) for the treatment of the fatal parvovirus, the purification of anti-parvovirus IgG from immunized dogs was assayed.

IgG purification was conducted on the obtained immune sera using two-stage dialysis, in which various concentrations of ammonium sulfate with several incubations and centrifugations were applied in multiple steps.

Using SDS-PAGE electrophoresis, the correct band sizes of the purified IgGs were observed and its concentration was assessed to be >22 mg/ml. Also, using quantitative ELISA, the specific anti-parvovirus IgG titer of the purified dog IgG was calculated to be considerably above the protective threshold titer. To do so, 13 parvoviral diarrheic puppies were randomly categorized into 3 treatment groups for 5 consecutive days. Administration of 4, 8 and 16 mg/kg bw/d of purified IgG to these puppies significantly improved all clinical symptoms including diarrhea, dehydration, appetite, vomiting and white blood cell (WBC) in all affected puppies in dose-dependent manner, comparing with those in the placebo-controlled group (n=8) that experienced 2 deaths, too.

This homologous anti-parvovirus IgG, which was purified through a novel, simple and inexpensive technology is expected to pass further clinical trials. Also, this IgG has the potential as a commercial product to reduce the burden of parvovirus infection in puppies.