Fatal Actinobacillosis in a Dairy Buffalo

Muhammad G. , M. Saqib, M. Athar: Fatal Actinobacillosis in a Dairy Buffalo. Acta Vet. Brno 2006, 75: 247-250. The present report describes a case of fatal actinobacillosis in a dairy buffalo (Bubalus bubalis). Clinical signs included a large multilobular, firm abscess located caudo-ventral to the right ear base, submandiblar and prescapular lymphadenopathy, fever and dyspnoea. Haemogram revealed an accelerated erythrocyte sedimentation rate and erythropenia. Provisional diagnosis of actinobacillosis was confirmed by the demonstration of a Gram-negative pleomorphic organism in pus, microscopic examination of a compression preparation of a sulphur granule as well as growth of the organism on blood agar. Intraperitoneal inoculation of pus in guinea pigs was fatal at around 48 hours post-injection. The LD50 of the Actinobacillus lignieresii isolate in mice was 10 4 colony forming unit per milliliter of Hank’s balanced salt solution. The animal died 12 hours after the initiation of surgical drainage of the abscess and administration of iodide, antibiotics and steroids. Necropsy findings included interlobular pneumonia, pulmonary abscessation and mediastinal lympadenopathy that were ascribed to metastatic spread of the organisms to the lungs which probably led to the death of the animal. This case report appears to be the first documentation of fatal actinobacillosis in the dairy buffalo. Actinobacillosis, Actinobacillus lignieresii, Bubalus bubalis, dairy buffalo Actinobacillosis is an infectious, chronic, generally non-fatal disease caused by Actinobacillus lignieresii. In cattle, it typically involves the tongue and hence is also known as “the Wooden Tongue”. The involvement of other organs is considered to be atypical (Mohanty and Singh 1970; Rebhun et al. 1988; Aslani et al. 1995; Holzhauer and Roumen 2002). The etiologic agent is found normally in the oropharynx and rumen of cattle and sheep (Smith 1990; Songer and Post 2005). The organism is an opportunistic pathogen and it causes chronic pyogranulomatous lesions of the soft tissues of head and neck regions in cows, buffalo, sheep, goats, and horses (Misra and Angelo 1981; Fubini and Campbel l 1983; Baum et al. 1984; Kumar and Parihar 1998; Hirsh et al. 2004; Songer and Post 2005). Clinically, the lesions appear as nodules, multiple abscesses, ulcers or draining fistulae. Spontaneous actinobacillosis in the buffalo (Bubalus bubalis) is reportedly non-fatal (Akhtar and Cheema 1964; Ahmad et al. 1986). The present report describes a case of atypical, fatal actinobacillosis in a dairy buffalo.