2. Actinobacillosis (Actinobacillus lignieresii)
• It is chronic disease affecting soft tissue of cattle and sheep and
characterized by Pyogranulomatous glossitis (Wooden Tongue ), also involve
Lymph nodes .
• The tongue is enlarged, immobile, hard in consistency and protruded from
the mouth.
• Cause by Actinobacillus lignieresii. Gram negative bacillus
• Pathognomic lesions: The affected tongue is enlarged, stiff and has multiple
small abscesses
• The pus is thick, smooth and shiny and shows sulfur grannules
• Abscess are also seen in the lungs, liver, skin and forestomach.
• The regional lymph nodes suffered from small and multiple abscess and
enlarged
3. Case Study of Actinobacillosis
• Animal: Bovine, 11 years, red cattle,
• The cow developed intermittent, moderate respiratory distress over a period of
approximately 2 weeks and off feed. In the ventral larynx, a mass measuring 5 x 3
x 2 cm was located. It had a bumpy, non-ulcerated surface. The cut surface was
lobulated, with areas of yellow-brown, caseous tissue surrounded by a firmer,
greyish to white tissue. When pressure was applied to the sample, tiny, yellow
granules appeared on the surface.
• Histological examination of the tissue revealed multiple, purple colonies of
bacteria surrounded by a mixture of neutrophils, macrophages and
multinucleated giant cells in a collagen rich stroma. The purple colonies had club
shaped structures radiating out on the surface.
• Diagnosis: Larynx, pyogranulomatous inflammation with intralesional club
colonies consistent with Actinobacillus lignieresii.
4. Gross Pathology
Actinobacillosis or “wooden”
tongue. ( A ) The tongue is
markedly enlarge with several
areas of chronic ulceration along its
lateral edge. ( B ) Cross section
through a case of wooden tongue
with numerous pyogranulomas (
arrow ) scattered throughout the
tongue. This is typically caused by
Actinobacillus lignieresii .
5.
6.
7. The pyogranulomas are centered on colonies of bacilli encased in brightly eosinophilic
Splendore-Hoeppli material.
8. Necrotic center of the prescapular lymph node of a dairy cow, with club-shaped
clusters and Splendore–Hoeppli material surrounded by neutrophils and
macrophages
