WACO, Texas (CBS Local) – A dog’s touching farewell to his best friend is breaking hearts on social media.

According to multiple reports, Joseph Scaramucci posted several pictures on Facebook of his pup Mattis, who was clearly heartbroken over the death of the family’s guinea pig. Otis the guinea pig reportedly died on July 28 after the family returned from vacation.

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Brittany Scaramucci told local reporters Mattis refused to leave his best friend’s side until his passed over the weekend. “When I went to pick up the cage and clean it up, he stayed right with me and then sat next to it and in it on the sidewalk,” Brittany said, via KFDA. “When I lifted the lid off, he made it pretty obvious that he knew something was wrong and just looked at me like ‘what is going on?’ It broke my heart.”

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The Scaramuccis report that Mattis is still mourning the loss of his friend of four years. “Even yesterday morning Brittany was commenting on how he wouldn’t eat,” Joseph Scaramucci added. “Mattis just seems to tolerate everything, so I was surprised.”

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The depressed canine probably shouldn’t surprise anyone. A 2014 study found that dogs pick up on emotions the same way humans do, so Mattis’ touching display for his dying friend was more natural than some might think.