Leerink analyst David Larsen notes that Patterson's Animal Health International unit is the subject of a criminal investigation in Virginia according to its Q1 10Q filed. For now, the analyst does not believe the criminal investigation poses a substantial threat to the stock, especially given that the investigation is focused on a period prior to Patterson's acquisition of AHI in June 2015. According to the filing, AHI may have sold prescription animal health products to certain locations and people who lacked the proper licenses in Virginia and Tennessee which violated both state and federal laws, he adds. Overall, Larsen believes the criminal investigation represents a modest risk to the stock.