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This article is still under construction. |
| Also known as: | Wooden tongue |
Description
An infectious disease caused by the gram-negative coccobacilliActinobacillus lignieresii. Characterised by inflammation of the soft tissues of the head especially the tongue and pharangeal lymph nodes of cattle and sheep. Usually due to direct penetration into tongue of cattle
- In cattle - very widespread in world, but rather sporadic, less common now than it was.
Clinical
- Seen in youngish animals in beef breed, especially sucklers on poor forage.
- Starts like foot and mouth disease - dull, salivating (if only one animal is unlikely to foot and mouth). - nearly always sporadic.
- ongue feels like a big lump of wood especially dorsal part of posterior 2/3rds.
- Small areas of ulceration are often found on side of tongue.
Pathogenesis
- Very similar to Mandibular Osteomyelitis ("lumpy jaw").
- Causal agent: Actinobacillus lignieresii (small gram -ve) gets into tongue via small abrasions.
- Pathogen is very widespread in environment.
- Progressive disease - low virulence but high persistence so animal may stop eating and eventually die but can be treated.
Pathology
- If cut into tongue, substance of tongue changed to fibrous stroma with raised red nodules. (2-3mm across).
- This lesion is a pyogenic granuloma with central sulphur body.
- Can spread from tongue to other tissues e.g. retropharyngeal lymph nodes and palate.
- This type of lesion is caused by the host response to the pathogen, rather than directly a pathogen effect.
Other sites
- Occasionally can see generalised infections but more commonly spreads to local lymph nodes of alimentary tract.
- Organism can be inhaled causing actinobacillus pneumonia.
- Can affect rumen wall.
- In skin forms a neoplastic like mass in dermis.
- Small granulomatous lesions containing 'sulfa granules' of large numbers of gram-negative rods