Capsules of Pasteurella multocida serogroups A, D and F contain mucopolysaccharides which block antigenic determinants and prevent phagocytosis. In this study, capsules of serogroup A, D and F strains of P. multocida were depolymerized by enzyme treatment. Capsule depolymerization of serogroup D and F strains with chondroitinase increased indirect hemagglutination (IHA) test titers and enhanced phagocytosis by swine neutrophils. Capsule depolymerization of serogroup A strains with hyaluronidase increased IHA titers, but depolymerization with chondroitinase did not. When serogroup A strains were treated with a combination of chondroitinase and hyaluronidase, IHA test titers were lower than titers of the same strains treated with hyaluronidase alone. Combined enzyme treatment of serogroup D strains resulted in IHA test titers similar to those of chondroitinase treatment alone.