Actinomycosis (Lumpy Jaw) Disease

Actinomycosis (Lumpy Jaw) disease is a chronic, sporadic disease, affecting cattle followed by pigs and horses. In association with Brucella abortus, it causes “Fistulous withers” and “Poll evil” in horses.

Rarefying osteomyelitis of the bone in skull, enlargement of mammary gland, inflammation of bursa of the ligamentum nuchae are the prominent problems develops in cattle, pigs and horses.

Etiology

• The disease is caused by Actinomyces bovis.
• As cultured organism has both bacterial and fungus features it is ascribed as fungal like bacteria.
• The organism is associated with Coryenebacterium pyogenes and Staphylococcus.
• A. israeli causes actinomycosis in human, but A. bovis and A. israeli are considered as different organism.
• There is no evidence for A.bovis causing infection in human.

Epidemiology

Prevalence of infection

• The disease is world wide in distribution.
• It is recorded from various regions in India.
• Incidence is higher in straw and silage fed cattle, because, these coarse materials injure the buccal mucosa and spread the infection further in to the other parts of the body.
• Its occurrence is sporadic and prevalent in India.

Predisposing factors

• Eruption of permanent teeth in young animals favors the organism to penetrate sub-epithelial tissues.

Source of infection

• Other diseases causing vesicular and erosive stomatitis predispose animals for Actinobacillosis.
• Infection is spread through discharges from infected animals.
• Grazing on infected pastures.

Transmission

• Organism also exists as normal inhabitant in the oral cavity.
• Infection occurs through abraded injury or wounds induced by coarse feed stuff .
• Infection spread through dental alveoli at the of time of eruption of teeth.
• Alimentary tract harbor A. bovis from where it invade subcutaneous tissues through injury made by sharp object.
• Animal to animal transmission.
• Animal to human transmission is rare.

Host affected

• Infection is sporadic and more common in cattle of 2-5 years old.
• The disease rarely affects pigs, horses and goats.
• Chronic actinomycosis prevails in horses and dogs.

Pathogenesis

• Pathogenesis developed purely by physical activity.
• The organisms does not produce toxin.
• A. bovis produces lesions in cervico-facial region, mandible, subcutaneous tissues of the lower jaw in cattle.
• Infection of rumen leads to ruminitis and indigestion which results in partial starvation.
• Serologically and clinically active cases of pulmonary actinomycosis has been recorded in cattle.
• Primarily the jawbone and then alimentary mucosa is affected.
• But rarely, the organism enters the haematogeous route.
• Rarefication and osteomyelitis of jaw bone interfere with mastication and prehension.

Clinical Signs

Cattle

• The disease is sporadic and occasionally endemic in this species.
• Initially hard, painless, distinct swelling at the level of central molar teeth of the mandible or maxilla causes problem in mastication, and digestion.
• Partial block in trachea causes dyspnoea, followed by development of painful granulomatouss swelling, which breaks through skin and discharge through one or more openings.
• Invasion and damage to bony tissues causes proliferative osteitis.
• Oral cavity exhibits loose teeth or missing teeth as a result halitosis, hyper salivation and dysphagia noticed.
• Occasionally diarrhoea with passage of undigested food materials seen
• Distended stomach, allotriophagia observed.
• It has more prolonged course than Actinobacillosis and leading to suppurative granulomatous mass on superficial layer of jaw and ensues the formation of sinus tract.
• Discharge from abscess are sticky, mucoid, purulent and honey like exudates containing minute hard, yellowish white sulphur granules.
• Infection spread to adjacent bones and lymphatic channels in case of prolonged infection.
• Localization of infection in testis of bull, brain and lungs occurs.
• Old lesions heal, however, fresh lesion develops.

Horses

• Bursa between the nuchal ligament and primary thoracic spine and bursa between the nuchal ligament and atlas axis are affected.
• A. bovis and Br. abortus jointly develops suppuration and granulation leads to poll evil and Fistulous withers.

Pigs

• Rarely suffer from extensive granulomatous lesions of the skin over the udder and become emaciated.
• Wasting due to visceral actinomycosis rarely occurs.

Dogs

• Chronic pyogranulomatous lesion appears on the skin of sub-mandibular, abdomen and thoracic region.

Necropsy Findings

• Rarefication of bones in widespread infection.
• Softening and liquefaction of pus gradually spread to cortex and rarefies it and which in turn forms a sub-perioisteal bone.
• Oesophagus and anterior wall of the reticulum containing pockets of pus and spread to causes chronic local peritonitis.
• Lumpy jaw is an important manifestation of a suppurative osteomyelitis of the mandible.
• Affected bone is filled with distinct granulation tissues and nodules
• Miliary nodules present in udder and lungs.
• In sows infected udder is indurated and fibrosed with suppuration.
• Mild abomasitis and enteritis occurs.

Diagnosis

• Based on clinical signs and necropsy findings.
• Isolation and identification of organism.
• Stained pus containing sulphur granules of A. bovis.
• Tissue section show cellular changes
• The granules of A. bovis exhibit the grit, non-acid fast branched filaments while stained by brown modification of Gram’s stain
• In a glass slide, a small drop of pus and water is mixed and examined under low power microscope. It reveals irregular club shaped, filamentous gram positive bacteria.

Sample Collection

Pus from unopened lesion must be aspirated by a syringe and examined the visible granules by naked eye.

Differential Diagnosis

• Foreign body problem
• Chronic peritonitis
• Cutaneous or mammary disease
• Borreliosis

Treatment

• Early lesion can be reduced using iodine and sulphur therapy.
• Streptomycin is used successfully.
• Surgical correction of abscess can be done
• Administer Sodium Iodide 5-8gm in 250-500 ml distilled water I/V. Isoniazide 20 ml /kg body weight for 10 days @ 10-20 mg /kg body weight daily orally for 30 days.
• Response in advanced case is poor.
• Combination of Streptomycin with iodide and surgical drainage may provide good response.
• Cryotherapy with liquid nitrogen is found to be effective for treating abscess and rarefication.

Prevention

• No vaccine against this disease is available.

Control

• Isolation of affected animals.
• Disposal of affected animals.
• Feed and water trough meant for affected animals should be disinfected.
• Changes in grazing management.