Culture is when a sample taken from a pet is allowed to grow, commonly in a petri dish. Bacterial and fungal species multiply until their colonies can be seen with the naked eye and identified. This allows the actual species of bacteria or fungi present in a sample to be listed.
Some viruses can also be cultured but this is more complex and requires a specific viral culture test.
Knowing what bacteria are present allows vets to choose antibiotics that have a higher change of working well.
However, antibiotic resistance is present across the spectrum of available antibiotics, so culture is often combined with a sensitivity test to check the reaction of the specific bacteria to specific antibiotics in the laboratory.