Riv­er, the real-world dog that inspired Fall­out 4’s Dog­meat, has passed. River’s own­er, Joel Burgess, con­firmed the unfor­tu­nate news in good­bye post on social media.

I said good­bye today to Riv­er, who most of you know as Fall­out 4’s Dog­meat,” Burgess said. “Heart­bro­ken does­n’t cov­er it, but I won’t eulo­gize her here. For twit­ter, I thought it’d be appro­pri­ate to look back at her impact on that game.”

Burgess released a series of tweets, reveal­ing insid­er infor­ma­tion about how Bethes­da end­ed up putting his beloved dog into Fall­out 4. Burgess stat­ed the team want­ed to avoid mak­ing Dog­meat feel like a “canine weapon and noth­ing more.”

What we want­ed was a com­pan­ion first, and a com­bat ally sec­ond,” he said.

The stu­dio did con­sid­er cast­ing a “pro­fes­sion­al” dog who had for­mal police or media train­ing, but Bethes­da choose to cast Riv­er, because it was right for the project. The deci­sion was well-received, with Dog­meat even win­ning an award.

You can see a selec­tion of Burgess’ tweets about Riv­er below, but you can go view the rest on Twit­ter. Burgess also encour­ages peo­ple to vol­un­teer with ani­mal res­cue cam­paigns where they live or make dona­tions when they can.

Dog­meat is a teth­er. He grounds you in the world, will always stand by you, lead you to your fam­i­ly, and antic­i­pate your needs. He wants you to be safe and happy.nIn oth­er words, he loves you. And if love is River’s lega­cy, I am con­tent­ed,” Burgess said. “Rest in peace, big girl.”