By Mike Puccinelli

CHICAGO (CBS) — As any animal owner will tell you, pets are precious members of the family.

So, when one suburban family discovered a life-threatening condition with their beloved dog, they allowed her to become the second-smallest dog to undergo a unique procedure.

Five months ago, the Cassidy family dog, Tiffany, left a routine checkup and something, clearly, was wrong.

“When we walked out, she went on all fours down on the ground,” said Pam Cassidy. “She couldn’t hold her weight up.”

The vet first thought Tiffany was having a bad reaction to her vaccinations, but it was actually a problem with her liver.

“It’s a vessel that’s bypassing the liver and taking all the toxins throughout the body,” said vet Cris Otoni. “When those toxins run through the brain, that’s when they are having the symptoms”

“Basically she was acting like she was drunk all the time,” said Brett Cassidy.

Vets put Tiffany on medication, but she needed more.

Surgery on the liver to treat this condition is risky. Now vets prefer minimally invasive treatment, entering through the jugular vein. However, the procedure is difficult for a dog of Tiffany’s size.

That’s when vets from the VCA in Downers Grove stepped up to the plate.

“There’s a worry that her jugular vein was going to be too small to pass all the guide wires that were needed,” said VCA’s Felipe Galvao. “There was a worry we weren’t going to be able to find the vessel.”

In spite of any concerns, there wasn’t much of a choice. “I don’t think she had very long to live,” Galvo said.

The team performed the two-hour surgery, coiling off the bad vessel and putting a stent in the good vessel to guide the blood in the right direction. The procedure cost $20,000, but the Cassidy family said the price was worth it.

“It was really a miracle how quickly she changed,” said Brett Cassidy.