Streptococcus suis is one of the most important causes of bacterial disease in post-weaned piglets. Affected animals suffer from meningitis (affected brain), endocarditis (affected heart), arthritis (affected joints) and septicemia (general infection). There are 35 serotypes of S. suis (same bacteria but different antigens). Some of these serotypes (such as serotype 2) can also affect humans (transmission from pigs), causing serious disease. Usually, veterinarians use antibiotics to treat and even protect animals.