Exhibit 99.1 NEWS RELEASE CHARLES RIVER LABORATORIES ANNOUNCES THIRD-QUARTER 2025 RESULTS – Third-Quarter Revenue of $1.00 Billion – – Third-Quarter GAAP Earnings per Share of$1.10 and Non-GAAP Earnings per Share of $2.43 – – Updates 2025 Guidance – WILMINGTON, MA, November 5, 2025 – Charles River Laboratories International, Inc. (NYSE: CRL) today reported its results for the third quarter of 2025. For the quarter, revenue was$1.00 billion, a decrease of 0.5% from $1.01 billion in the third quarter of 202 ...