Cattle bottleneck (IMAGE) Michigan State University Caption Brucella (yellow ovals) can infect a cow through the cow's eye and travel from there to the lymph nodes, where they replicate. Credit Aretha Fiebig Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.