The discovery and development of antibiotics has been a literal lifesaver for both humans and animals. Before antibiotics, many bacterial infections led to death. What started as a minor infection burgeoned until the body could no longer survive it. After antibiotics, millions of lives were saved and surgeries became safer.
Unfortunately, bacteria are highly adaptable. They are able to evolve to become immune to the medications we throw at it. This process is called antibiotic resistance, and it is happening all the time. Our overuse of antibiotics has seriously accelerated this process.