Actinomyces viscosus

• • • Commensal of oral cavity of dogs and humans
    • Canine actinomycosis
    • Causes localised subcutaneous pyogranulomatous lesions and fibrovascular proliferation of peritoneal (peritonitis) and pleural surfaces in dogs
    • Leads to pyothorax
    • Respiratory distress
    • Cutaneous pustules in horses
    • Abortion in cattle
    • Rods contained in soft grey granules which release the organism when squashed
    • Two types of colonies: large and smooth colonies with V, Y and T configurations or small and rough colonies with short branching filaments
    • Grow in 10% carbon dioxide
    • Usually responds to penicillin