Swollen head syndrome in broiler chickens in Japan: Its pathology, microbiology and biochemistry

Abstract

SUMMARYFour-to-seven-week-old broilers with swollen head syndrome (SHS) from 4 different districts of Japan were examined for pathological, microbiological and biochemical findings. Periocular and mandibular subcutaneous swelling, sometimes accompanied by ocular, hepatic and cardiac lesions were observed. Histologically, diffuse fibrinopurulent inflammation with focal granulomatous lesions was characteristic of subcutaneous tissue of the head, especially periocular tissue. The air spaces of the cranial bones and middle ear showed fibrinopurulent inflammation. Upper respiratory lesions (rhinitis, sinusitis and tracheitis) were always present in chickens with SHS. The characteristic lesions of chicken colibacillosis, i.e. fibrinopurulent serositis, panophthalmitis, fibrinous thrombi in sinusoids of the liver and fibrinous exudation in the ellipsoids and lymphoid follicles of the spleen, were occasionally seen. No virological agents could be isolated. Turkey rhinotracheitis (TRT) virus gene was detected in tracheas from two flocks by reverse transcriptase polymerase chain reaction and serum antibodies against TRT virus were present. Escherichia coli and Staphylococcus aureus were isolated from subcutaneous lesions. Serum α 1 -acid glycoprotein, an acute phase protein, was present at high concentration in chickens with SHS. This study suggests that upper respiratory lesions induce E. coli invasion into subcutaneous connective tissue adjacent to the infraorbital sinus and nasal cavity, and SHS in this study may possibly be a local infection of E. coli in facial subcutaneous connective tissue.

Pathological study on the upper respiratory tract infection of chickens and isolation, identification of causal bacteria

“…There was no lesion in the trachea. Similar lesions were reported by many investigators (Nakamura et al, 1997;Rocio et al, 1998;Murakami et al, 2002;Jaswinder et al, 2005). (41.4%) were isolated from trachea and nasal sinuses of chickens.…”

The use of virus isolation, histopathology and immunoperoxidase techniques to study the dissemination of a chicken isolate of avian pneumovirus in chickens

“…Our findings reveal that virus replication in the sinus tissue is substantial and causes microscopical changes from 4 to 10 d.p.i., followed by deciliation, which lasts even longer. These observations could support the work of Nakamura et al (1997) who described the pathology of swollen head syndrome in broiler chickens, some of which were serologically positive for TRT, whilst in others TRT antigen was detected using a reverse transcriptase polymerase chain reaction. They suggested that sinusitis appears to induce Escherichia coli proliferation in the subcu- taneous tissue as a result of destruction of respiratory epithelium and that TRT virus is a candidate for causing the initial damage.…”

Attempts to reproduce swollen head syndrome in specific pathogen‐free chickens by inoculating withEscherichia coliand/or turkey rhinotracheitis virus

“…In Experiment 1, four strains of E. coli were used: TK 736 (serotype 02) from a liver of a chicken with perihepatitis, 139-A (serotype 078) from an air sac with airsacculitis, and TOK-1 and IBA-1 (untypable) from skin of a SHS case (Nakamura et al, 1997). In Experiment 2, TK 736 strain was used.…”

“…TRT virus, a pneumovirus, has been strongly implicated as a factor in SHS in chickens (Naylor & Jones, 1993). Escherichia coli has been consistently isolated from skin lesions of the head (Morley & Thomson, 1984;O'Brien, 1985;Pattison et al, 1989;Uramoto et al, 1990;Droual & Woolcock, 1994;Tanaka et al, 1995;Nakamura et al, 1997). Therefore, E. coli is thought to be a secondary complicating factor (Naylor & Jones, 1993).…”

“…Therefore, E. coli is thought to be a secondary complicating factor (Naylor & Jones, 1993). The first invasive sites of bacteria in the subcutaenous tissue of heads were estimated to be the eyelid or nasal membrane, because there was rhinitis (Morley & Thomson, 1984;Nakamura et al, 1997) and blepharitis (Nunoya et al, 1991;Droual & Woolcock, 1994;Nakamura et al, 1997).…”