ACTINOBACILLOSIS (WOODEN TONGUE OR TIMBER TONGUE)

  • It is a chronic infectious disease of animals caused by a gram -ve coccobacilli.
  • Aetiology- Actinobacillus lignieresi
  • This organism forms mulberry like colonies of various sizes.
  • Commonly seen in cattle

Mode of transmission-

  • pus or infected discharges from infected animals act as major source of infection.
  • Transmitted by contaminated food and water with the presence of oral mucosa injury.
  • Cattle get infected through ingestion of rough grasses, hard stem, sharp edges of grasses and seeds.
  • Calves acquire infection during eruption of teeth.
  • It survives for 4-5 days in forage.

Clinical signs

  • Affected tongue protudes with difficulty in swallowing
  • Ulcers and nodules are seen over tongue surface
  • Pus discharges from open abscess
  • Tongue becomes hard and swollen near the base
  • Excessive salivation occurs with difficulty in mastication
  • Nodules are also found at neck, lower jaw, oral cavity and lymph nodes
  • Normal tissue is replaced by fibrous tissue in affected portion of tongue which result in shrunken and immobile tongue
  • Lymph nodes may rupture and discharge yellowish pus
  • Ruminal tympany and abdominal pain occurs.

Diagnosis

  • From clinical signs and physical examination
  • Staining of discharged pus materials- Gram stain reveals presence of short G -ve bacilli
  • Culture for bacterial isolation can be done using 1% glucose blood agar, Macconkey agar which result in presence of small bluish white smooth convex colonies.
  • Histopathological observation- clubbed colonies surrounded by neutrophils, macrophages and giant cells.(Splendor- Hoeppli phenomenon)

Differential diagnosis-

  • Tuberculosis
  • Actinomycosis
  • Cancers
  • Leukemia
  • Abscess due to Corynebacterium pyogens

Treatment

  • Drainage of pus
  • Lugols iodine injected at the site of skin lesions
  • Potassium iodide- 6-10gm daily orally per animal for 7- 10 days
  • Sodium iodide- 1g per 12 kg bwt intravenously once
  • Streptomycin- 10mg per kg bwt daily for 3 days

Or

          Sulphonamide- sulphadimidine 1gm per 6.8kg bwt for 3 days

Or

          Ceftriaxone- 5-10 mg per kg bwt

Prevention and control

  • No vaccine is available
  • Infected animals should be isolated and treated separately
  • Animals should be fed with soft palatable diet
  • Contaminated feed should be avoided.