Miranda Lambert's beloved senior dog, Jessi, has died after 13 1/2 years of companionship.

The singer shared a tribute to her four-legged friend on social media Thursday, along with a slideshow of pictures of Jessi and the dog's brother, Waylon, who died in October 2020.

Miranda found the two pups on the side of the road in Oklahoma back in 2008 during a sleet storm. The singer explained that she and her mom -- who were driving together when they encountered the siblings -- were listening to Jessie Colter's 'I'm Jessi Colter' album at the time, which is how the two puppies got their names. Colter was married to fellow country music star Waylon Jennings from 1969 until his death in 2002.

Lambert went on to say that Jessi and her brother were inseparable their whole lives, up until his death last year.

"The truth is they belong together. They always have," she wrote. "I know she missed him terribly and we are so thankful to have had extra time. Today they are reunited at the rainbow bridge."

Waylon and Jessi were two of the many dogs and other animals that call Lambert's farm home. The singer and her mom also established their MuttNation Foundation in 2009 in support of shelter pets.

"I can't put into words what a dog's love does to your heart. But if you have one, you already know," Miranda said in the conclusion of her tribute post. "It's so hard to let them go but the love is worth it."