Natural lymphatic (“atypical”) actinobacillosis in cattle caused by Actinobacillus lignieresii

Abstract

Bovine actinobacillosis is typically characterized by pyogranulomatous glossitis (wooden tongue). The involvement of other tissues, generally the skin or lymph nodes, has been regarded as atypical or cutaneous. We describe herein 2 outbreaks of actinobacillosis affecting primarily the lymph nodes of the head and neck. The disease affected 40 of 540 lactating cows in a dairy herd, and 5 of 335 two-y-old steers in a beef herd. Multiple or single, occasionally ulcerated nodules were observed in the region of the mandible, neck, and shoulder, including the parotid, submandibular, retropharyngeal, and prescapular lymph nodes. The histologic lesions were multifocal pyogranulomatous lymphadenitis, dermatitis, and cellulitis with Splendore-Hoeppli material. One steer had an exophytic pyogranuloma in the gingiva and another died because of ruminal tympany secondary to oropharyngeal and esophageal obstruction by a pyogranulomatous mass. Actinobacillus lignieresii was isolated from the lesions and identified by amplification, sequencing, and analysis of the 16S ribosomal (r)DNA gene. Seven of 8 cows recovered after treatment with sodium iodide. Lymphatic actinobacillosis is a frequent disease in Uruguay, southern Brazil, and Argentina. Morbidity is 1-50%; mortality is <1%. A. lignieresii apparently penetrates the intact oral and pharyngeal mucosa, infecting primarily the regional lymph nodes. Later, lesions may extend to the subcutaneous tissue and the skin, causing ulceration. Affected cattle with draining pyogranulomas contaminate the environment, favoring disease transmission, and should be treated with sodium iodide or antibiotics and isolated from the herd in order to control the disease.

Atypical actinobacillosis affecting hind limbs and lungs in a single beef cattle herd

“…Actinobacillosis usually is considered a sporadic condition, typically involving the tongue in cattle (“wooden tongue”) . Lymphadenitis and granulomatous skin lesions involving other tissues (oral cavity, fore‐stomachs, skin of the head, neck and occasionally limbs) also have been reported, sometimes with several animals concomitantly affected in a single herd . In our report, 2 animals from a single herd had nodular dermatitis affecting the hind limbs with associated swelling, enlarged regional lymph nodes, pneumonia, and weight loss.…”

Actinobacillosis outbreak in cattle with clinical manifestation of hippopotamus-like face

“…Actinobacillosis is a cosmopolitan disease of sporadic occurrence characterized by the inflammatory piogranulomatous reaction. The disease affects cattle and less commonly sheep, pigs and horses (Andreazza et al 2013, Caffarena et al 2017. In ruminants, it is caused by Actinobacillus lignieresii, gramnegative aerobic bacterium, present in the oral cavity, upper respiratory tract, and rumen (Andreazza et al 2013).…”

“…Actinobacillosis, in its classical form, presents with lesions in the tongue and regional lymph nodes of the head and neck (Andreazza et al 2013, Caffarena et al 2017. Atypical cases are described by several authors and characterized by skin lesions (Margineda et al 2013), respiratory system lesions (Peli Agnelo et al 2009), lymph nodes lesions (Caffarena et al 2017) and generalized lymph nodes and organs lesions (Kasuya et al 2017). Lesions on the lips, palate, pharynx, nasal pits and face, when diffuse lead to a clinical picture called hippo-like face.…”

Diverse strains of Actinobacillus lignieresii isolated from clinically affected cattle in a geographically restricted area

“…There has been a report of an outbreak of cutaneous actinobacillosis with high morbidity over 11 months associated with overcrowding, rough food and a contaminated environment . In an outbreak of lymphatic, or atypical, actinobacillosis in a dairy herd, 40 of 540 cows had lesions in the lymph nodes of the mandible and neck …”

“…6 In an outbreak of lymphatic, or atypical, actinobacillosis in a dairy herd, 40 of 540 cows had lesions in the lymph nodes of the mandible and neck. 7 A. lignieresii is very closely related to the pig pathogen Actinobacillus pleuropneumoniae, with 16S rRNA sequencing unable to distinguish the two species. 8 However, A. lignieresii does not affect pigs, and A. pleuropneumoniae does not affect cattle.…”