ACTINOBACILLOSIS (WOODEN TONGUE)

Dr Nadir HussainDVM,UVAS Lahore

Definition

infectious disease of ruminants

caused by actinobacillus lignieresii

inflammation of soft tissue of the head especially tongue

Etiology Actinobacillus lignieresii

gram-negative coccibacilli

Epidemiology worldwide in distribution

sporadic occurrence on individual farms

most instances --- occasional cases

sheep flocks a morbidity rate up to 25%

Rare in horses.

Source of infection and transmission Actinobacillus lignieresii --- normal inhabitant of

oral cavity and rumen

susceptible to ordinary environmental influences

does not survive -- more than 5 days on hay or straw

Infection in soft tissues --- damage to the oral mucosa.

Source of infection and transmission ulcerating or penetrating lesions to sulcus of

tongue penetrating lesions in the apex lacerations to the side of the body of the tongue Actinobacillus granulomas on atypical sites external nares / jugular furrow Iatrogenic infection of surgical wound incision Infection of cheeks---bilateral

Pathogenesis Local infection --- acute inflammatory reaction

development of granulomatous lesions

necrosis and suppuration occur

discharges of pus to the exterior

Pathogenesis Spread to regional lymph nodes

Lingual involvement --- interfere prehension and mastication

Clinical Findings onset of glossal actinobacillosis is usually acute unable to eat for 48 hours excessive salivation and gentle chewing of tongue tongue is swollen and hard---at the base tip normal Manipulation of tongue causes pain, resentment Nodules and ulcers on the side of the tongue

Clinical Findings later stages---acute inflammation --- replaced

fibrous tissue--- tongue ---shrunken and immobile interference with prehension Lymphadenitis is common enlargement of sub-maxillary and parotid nodes Local firm swellings ---- rupture --- discharge of

thin, non-odorous pus

Clinical Findings Healing is slow and relapse is common

Enlargement of retropharyngeal nodes --- interfere swallowing --- loud snoring respiration

Cutaneous actinobacillosis --- granulomas --- external nares, cheeks, skin, eyelid, hind limbs

External trauma -- usual initiating cause.

Clinical Pathology/Diagnosis Purulent discharges --- sulfur bodies -- granular in

nature

microscopic examination--club-like rosettes with a central mass of bacteria

Examination of smear or culture of pus---A. lignieresii

Differential diagnosis Foreign bodies in the mouth Rabies Esophageal obstruction Tuberculosis Cutaneous Lymphosarcoma

Treatment Iodides --- standard treatment

Oral or IV dosing of iodides

Potassium iodide, 6-10 gm/day for 7-10 days, given orally

Treatment may continued until iodism develops

Treatment Lacrimation, anorexia, coughing, and appearance

of dandruff ---maximum systemic level of iodine NaI (70 mg/kg BW) IV 10-20% solution in one

dose One dose of potassium iodide or one injection of

sodium iodide is usually sufficient for soft tissue lesions,

acute signs in actinobacillosis disappear in 24-48 hours after treatment.

Treatment sulfonamides, penicillin, streptomycin, and the

broad spectrum antibiotics

Streptomycin at 5 gm/day for 3 days IM -- good results in actinomycosis -- when combined with iodides and surgical treatment

Isoniazid at 10 mg/kg BW orally or IM for 3-4 weeks with iodides