Acute Myositis Associated with <i>Hemophilus Parasuis</i> in Primary SPF Sows

Abstract

Hemophilus parasuis (HPS) infection is frequently associated with polyserositis and meningitis (Glasser’s disease). HPS infection is recognized as a serious infection in susceptible specific pathogen-free (SPF) hogs. Acute HPS septicemia 4 or pneumonia, without polyserositis, has also been reported. This report describes an acute fasciitis and myositis associated with HPS infection in primary SPF sows. Thirty SPF sows were inappetent, weak, and ataxic. Several of these sows had swollen heads and 7 sows died over a 48hour period. Rectal temperatures ranged from 105 to 108 F. The remaining 23 sows responded to antibiotic therapy and recovered fully, suggesting a bacterial infection. The sows were second parity and were ceasarian derived through an SPF laboratory. They had no previous disease problems. Two of the 7 sows were necropsied. One sow had extensive subcutaneous edema of the head region (Fig. 1). Lesions of septicemia, polyserositis, or pneumonia were not present. The other sow lacked significant gross lesions. The lung, liver, and meninges of both sows were cultured aerobically in 5% bovine blood agar, 5% bovine blood Columbia agar, MacConkey agar, and mannitol salt agar, and on a 5% ovine blood agar plate with a Staphylococcus epidermidis nurse streak incubated under 5% CO, atmosphere. No bacteria were isolated from the above organs of either sow. The masseter muscle from 1 sow was cultured on a bovine blood agar plate under anaerobic conditions as well as with a Staphylococcus epidermidis nurse streak under 5% CO, atmosphere. These procedures failed to identify any anaerobic bacteria. Tiny, smooth, grayish colored, translucent, nonhemolytic bacterial colonies satellited the Staphy-