Streptococcus bovis

S. bovis is a Gram positive, sphere-shaped (cocci) organism that grows in pairs or chains. Its size is approximately 0.5-2.0 micrometers in diameter (Photo courtesy of the Online Photo Atlas in Veterinary Disease Biology).

When gut conditions are favorable for S. bovis to grow, it will flourish quickly. Studies suggest that in an environment with elevated starch/sugars, and a low pH, S. bovis may double every 13 minutes.

​The lactic acid production is theoretically dependent on S. bovis and can lead to problems in the rumen, such as decreases in pH, damage to the rumen wall, and may eventually lead to severe rumen damage and liver abscesses.

S. bovis is a key player in ruminal acidosis, predominately feedlot cattle as they are subject to heavy concentrate diets. Without an adaptation period, engorgement of grains may allow the opportunistic S. bovis to take hold in the rumen​.