Arterivirus is a genus of viruses that primarily infects mammals, particularly pigs and horses. These viruses are known for causing various diseases, including porcine reproductive and respiratory syndrome (PRRS) in pigs, which can lead to significant economic losses in the livestock industry. The structure of arteriviruses includes a single-stranded RNA genome, which allows them to replicate within host cells. They are enveloped viruses, meaning they have a lipid membrane that helps them enter host cells. Understanding arteriviruses is crucial for developing vaccines and treatments to control the diseases they cause.