Actinomycosis
Actinomyces are gram-positive bacteria that can cause pyogranulomatous inflammation characterized by formation of small rounded masses with ulcerated surface in animals and humans. Classically, actinomycosis is a disease of cattle, but it also occurs in other animal species, and as a facial and oral infection in man.
Actinomyces bacteria normally live in the mouth and in the nasal passages near the throat. Actinomycetes may become pathologic due to poor oral hygiene, dental/periodontal problems, trauma and following oral surgical procedures. Pulmonary actinomycosis may develop as a result of aspiration of actinomyces that originated from dental plaque and diseased gums. Several species are associated with the disease in dogs: Actinomyces bovis, Actinomyces hordeovulneris, and Actinomyces viscosus.
Actinomyces bovis causes loose teeth and difficulty breathing due to swelling of the nasal cavity. Actinomyces hordeovulneris causes abscesses in the liver and spleen and generalized infections in the cavities surrounding the lungs and bacterial arthritis.
Two Forms of Actinomycosis
Two forms of actinomycosis are usually seen in dogs. The more common is a skin abscess or mycetoma. This form, resulting from a skin wound, usually responds well to treatment. Actinomyces viscosus causes chronic pneumonia, inflammation of cavities surrounding the lungs, and skin abscesses associated with fever, pain and swelling of the skin.
Canine interdigital actinomycosis is especially likely to result from foxtail foreign body penetration, or introduced into a wound by grooming.
Diagnosis of Actinomycosis
Skin form of actinomycosis is diagnosed based on cytological examination, bacteriologic culture, or histologic examination.
Treatment of Actinomycosis
Treatment of actinomycosis depends on the bacterium species that causes the disease. The cutaneous (skin) form may require surgical cleaning, drainage, and administration of antibiotics. In some dogs there may be recurring infections that will require several surgical procedures. The combination of surgery and antibiotic treatment appears to be superior to antibiotic treatment alone in resolving cutaneous actinomycosis.
Related Diseases and Disorders
|