At only 9 days old, a foal named Tye lost his mother. But that same night he gained an unexpected friend — an Australian cattle dog named Zip.

Zip had never shown much interest in his horse siblings. “We raise foals every year, and he would kind of look in the door and just look at them,” Karla Swindle, Zip’s mom, told The Dodo.

But on that fateful night in March, it was as if the 5-year-old rescue dog could tell he was needed.

Tye’s mother became sick days after giving birth, and despite treatment, quickly went downhill. When things looked their bleakest for the mother and baby, Swindle stayed by their side. As always, Zip tagged along after his owner.

“I spent the night at the barn taking care of the mama horse, hoping that I could pull her through,” Swindle said. “Zip stayed with me in the alley of the barn all night — the foal was laying in the alley, and he just lay there beside the foal.”

“He was whining,” Swindle added. “You could tell that Zip knew something was wrong that night.”

The next morning, Tye lost his mother, but he wasn’t alone.

Zip insisted on keeping the newborn horse company, comforting the little animal with his presence. When Zip was around, Tye was relaxed and happy. “It seemed to me that the foal knew that the dog was trying to help him,” Swindle said, “which is so sweet.”

For six weeks, Zip wouldn’t let Tye out of his sight. Whenever Swindle went to feed the foal, Zip was first in line to greet the little horse. “Every time I would take off to the barn, Zip would run to the stall, and stand in front of the stall and wait for me to get there,” Swindle said. “He would beat me to the barn every time.”

“As soon as I opened the door, he would about knock me down before I could get in there,” she added. “If the foal was laying down, he would go over there and lay his head on him.”

As months passed, Tye quickly put on weight, growing into a healthy young horse — in part, thanks to his adoptive dad.

Now, Tye spends most days out in the pasture with his older sister, who is teaching him the ins and outs of being a horse. And while Zip still accompanies Swindle to the barn, he doesn’t beg to go in the stall with Tye anymore.

“The foal is a little rough now,” Swindle said, “raring up, trying to play, so Zip kind of stays away from him now.”

The proud dad understands that Tye needs to test his independence, and it doesn’t make their relationship any less special.

“You could tell that when the foal needed Zip, Zip was there for him,” Swindle said. “And now Zip knows that the foal is OK, so they kind of went their separate ways.”

But it seems the little horse has opened up room in the older dog’s heart — space that he has since filled with another baby.

“He loves my granddaughter,” Swindle said. “Whenever she comes over here, he goes directly to her. He treats her like he did the foal. He just loves to be around her.”