Yes, as of August 2019, Hagen-Renaker is still open in San Dimas, California. The current owner is Sue Nikas, daughter of the company founders, John and Maxine Renaker. It is the only pottery still making ceramic animal miniatures in the United States.
In addition, Kristina Lucas Francis runs a licensed offshoot, Hagen-Renaker Tennessee, which is currently issuing limited runs of selected Hagen-Renaker horses and other pieces. More information can be found at the Hagen-Renaker Collector’s Club group on Facebook.