(CNN) He might be an old dog, but he's a fighter.

A 12-year-old German shepherd in Missouri barely survived after being buried in a sinkhole for 72 hours.

The hunt for Maverick started February 4 after he wandered from his home in Parkville, north of Kansas City.

"He had on his invisible fence collar," said owner Lisa Van Valkenburgh. "But that didn't stop him from walking out of bounds."

Hours turned into days as the entire Van Valkenburgh family searched for their missing pooch.

Photos: Dog rescued after being buried alive in sinkhole Photos: Dog rescued after being buried alive in sinkhole Maverick, a 12-year-old German shepherd, was trapped in a Missouri sinkhole for 72 hours. Hide Caption 1 of 5 Photos: Dog rescued after being buried alive in sinkhole Maverick had clay covering his snout, ears and eyes when he was rescued. It took veterinarians an hour to stabilize him. Hide Caption 2 of 5 Photos: Dog rescued after being buried alive in sinkhole The Van Valkenburgh family was searching for Maverick for three days when they found him stuck in the hole. Hide Caption 3 of 5 Photos: Dog rescued after being buried alive in sinkhole One of Maverick's teeth punctured his lip and broke off when he fell into the hole. He was severely dehydrated and stayed at the hospital for four days. Hide Caption 4 of 5 Photos: Dog rescued after being buried alive in sinkhole Maverick is getting back to his normal self each day. "It still for the life of me shocks me that I found him," said owner Lisa Van Valkenburgh. Hide Caption 5 of 5

Lisa Van Valkenburgh, a 44-year-old service adviser, said she was anxious because she thought Maverick might have fallen through ice into the lake around their house.

"My biggest fear is he had drowned," Van Valkenburgh told CNN. "I was afraid if he fell into the water he wouldn't have the strength in his legs to pull himself out."

The Van Valkenburghs searched everywhere and never gave up hope. Finally there was a clue -- or rather, a noise. While Mrs. Van Valkenburgh was walking around by the road she heard a faint howl coming from under the ground.

At first, she thought her dog was in the ditch below, stuck in a drain pipe.

"I jumped down frantically searching," she said. "A man stopped to help me when he saw a sinkhole at the side of the road."

Her dog was buried alive, clinging on to life.

Van Valkenburgh's son and husband came to try to dig the dog out, but Maverick was sucked into the mud and very weak.

The family was afraid that if they continued to try to pull him out of the sinkhole, the ground would cave in, so they called rescue authorities for help.

SPFD performs a dog rescue after he falls in a sink hole. Been missing for 72 hrs. Glad family is back together! pic.twitter.com/2gpM1mYFXv — Rich Carrizzo (@SPFPDFireChief) January 31, 2016

It took rescue crews almost two hours to dig Maverick out.

"They were awesome," said Van Valkenburgh. "They had to dig out under Maverick to release the suction the clay had on him."

Once he was rescued, the pooch was so weak and lifeless, according to Van Valkenburgh, they rushed him to the local emergency vet hospital.

It took veterinarians nearly an hour to stabilize Maverick, who was severely dehydrated.

After vets washed off all the clay that coated his snout, eyes and ears, Maverick was hooked up to an IV with antibiotics for the next three days.

One of Maverick's teeth punctured his lip and broke off as he fell through the hole. The dog also swallowed a large amount of clay, which showed up in his X-rays.

But Maverick powered through and gained enough strength to return home.

The Van Valkenburghs' three other dogs and a cat were all waiting for Maverick's homecoming Wednesday.

"His demeanor completely changed when he was reunited with his pack," said Van Valkenburgh.

In the week since Maverick fell in the sinkhole, he has slowly been getting back to normal.

"It still for the life of me shocks me that I found him."

The impact of Maverick's fall caused some health issues, however. Since he broke his tooth he is being fed chicken broth mixed into his food each night. He also has some skin irritation and gets wiped down with baby wipes a couple of times a day. And he now sports diapers since he cannot control his bladder.

But this doesn't stop him from being his defiant lovable self, according to Van Valkenburgh.

Maverick will no longer wander out of his yard since his electric collar has been traded for a tethered leash.

This wasn't the first time Maverick has survived a brush with death. Before being adopted by Van Valkenburgh, he was hit by a car and survived a raccoon trap.