Borrelia anserina is a helical spirochete bacterium with dimensions around 8-20/0,2-0,3[clarification needed] μm and with five to eight spirals.

[1] In microbiological laboratories, B. anserina bacteria can be grown on special protein-enriched media (rich in ovoalbumins or animal tissue (that contains myoglobin)), in anaerobic conditions.

The laboratory cultivation of B. anserina is rarely done and constitutes a diagnostic method in bird borreliosis and spirochetosis.

[1] B. anserina used to be maintained in embryonic chicken eggs or by serial passages in domestic chickens until in 1986 it was discovered that it could be cultivated in Barbour-Stoenner-Kelly (BSK) medium, which facilitated and made future research more cost-effective.

The major symptoms of an infection with B. anserina are: anemia, diarrhea, and severe neurological dysfunctions.