Streptococcus gallolyticus infections in racing pigeons, a review

S. gallolyticus, formerly known as S. bovis is known since 1988 as a facult ative pathogen of racing pigeons. Important clinical signs include acute mo rtality inability to fly, lameness, weight loss anti slimy green diarrhea. A pathognomic sign at post mortem examination is the presence of well descr ibed ur eas of necrosis in pectoral al muscle. Furthermore tenosynovitis of the supracoracoid muscle and arthritis of the knee, shoulder and hock can be observed. In one strain S. gallolyticus septicaemia was diagnosed in 10% of necropsied pigeons. Since S. gallolyticus was also isolated from nearly 40% of clinical healthy pigeons it is regarded as a facultative pathogen. Various biotypes, serotypes and culture supernatant phenotypes can be disti nguished. Supernatant phenotypes ale identified on the basis of the presenc e of either a T-1, T-2 or T-3 protein triplet and the presence ol absence o f an extracellular A protein. S. gallolyticus strains with A protein are hi ghly virulent, while strains with only T3 ol T2 protein ale of moderately, ol low virulence respectively. Fimbriae ale only seen in highly virulent an d some of the moderately virulent strains. Possible virulence factors inclu de survival in macrophages, adhesion to cells and toxin production. Infecti on with serotype 1 and 2 induces some degree of production against re-infec tion with serotype 1, which offers perspectives for the development of a va ccine. Experimentally ampicillin, doxycyclin and erythromycin have shown therapeut ic effects. For the treatment of clinical cases the rise of ampicillin is a dvocated together with hygienic measures, such as the use of grid floors an d avoiding over crowding.