Actinobacillus spp

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Actinobacillus spp-induced swelling of the left jaw in a beef cow

Actinobacillus spp are a group of commensal mucosal bacteria which can cause diseases worldwide in cattle.

A number of species have been isolated in cattle, including:

  • Actinobacillus lignieresii - pathogenic
  • A. succinogenes - nonpathogenic commensal of rumen[1]
  • A. actinoides - associated with suppurative pneumonia in calves (invalid nomenclature)

Colloquially known as 'actinobacillosis' or 'wooden tongue', A. lignieresii causes pyogranulomatous inflammation in cattle and results in tumorous abscesses of the tongue, neck, limbs[2] and upper respiratory tract[3]. Disseminated infections have also been recorded atypically in the lungs, pleura, udder, and subcutaneous tissue[4]. Disease associated with A. lignieresii is usually attributed to penetrating wounds (abrasive feed, iatrogenic) that damage the mucosal surface of the mouth[5].

Clinical signs

Signs associated with this disease are usually observed visually, such as deformities to the face or brisket. Examination of the mouth may reveal pus-filled growths on the tongue or cheek muscles. Brisket disease, due to dissemination of the bacteria may cause swelling or abscessation in this region. Fever, dysphagia and anorexia are common symptoms observed.

In disseminated disease, fever and pneumonia are accompanying signs and in some cases, this disease may be fatal.

Diagnosis

Diagnosis is usually based on presenting clinical signs, and laboratory isolation of Actinobacillus spp from purulent material removed during debulking. Definitive ELISA and PCR testing are available but are not usually required[6].

A diferential diagnosis would include abscesses of the retropharyngeal lymph nodes, fibropapilloma, viral papilloma and infectious (Mycobacterium spp), allergies, fungal infections or parasitic granuloma.

Treatment

Due to the sporadic nature of actinobacillosis, preventative measures are difficult to instigate. Herd outbreaks are associated with consumption of coarse, abrasive feeds.

Intravenous sodium iodide (70 mg/kg of a 10–20% solution), repeated weekly until a response is noted.

Systemic antimicrobial therapy is advised, with use of ceftiofur, penicillins and tetracyclines often beneficial at minimising severity. Surgical debulking or drainage of pus from lesions in cattle affected with facial lesions would alleviate symptoms.

Curative rates are low with this disease as there is often permanent scarring of tissues.

References

  1. Guettler MV et al (1999) Actinobacillus succinogenes sp. nov., a novel succinic-acid-producing strain from the bovine rumen. Int J Syst Bacteriol 49(1):207-216
  2. Biberstein EL (1981) In: Haemophilus, Pasteurella and Actinibacillus. Kilian M, Frederiksen W, Biberstein EL, editor. London: Academic Press; 1981. Haemophilus-Pasteurella-Actinobacillus: their significance in veterinary medicine; pp:61–73
  3. Angelo P et al (2009) An atypical case of respiratory actinobacillosis in a cow. J Vet Sci 10(3):265-267
  4. Rycroft AN & Garside LH (2000) Actinobacillus species and their role in animal disease. Vet J 159:18–36
  5. de Kruif A et al (1992) Actinobacillosis in bovine caesarean sections. Vet Rec 131(18):414-415
  6. Kokotovic B et al (2011) Genetic diversity of Actinobacillus lignieresii isolates from different hosts. Acta Vet Scand 53:6