A Denver dog named Cassius made a triumphant return to Pittsburgh to visit the veterinarians who saved his life one year ago, when he became desperately ill while on a family vacation.

Cassius, 9, a boxer-mix, pranced through the hallways of Pittsburgh Veterinary Specialty and Emergency Center in Ohio Township on Monday. He gleefully greeted veterinarians and other staff like they were great, good friends, for he knows them well. He spent nearly three months in their care, last August through November.

His case started out as a veterinary mystery. Lethargy and swelling steadily worsened and progressed to sepsis that nearly killed him. When one-third of the hair and skin sloughed off his body, leaving huge open wounds, internal medical specialist Tracey Jackson knew he was exhibiting the classic symptoms of snakebite.

Dr. Jackson administered intravenous antibiotics and other drugs. Veterinarian Jon Anderson and other surgeons performed four operations. They took skin from the sides of the dog's body and grafted it onto his chest, neck and legs where venom from a snake, believed to be a copperhead, had destroyed blood vessels and tissue.

"A lesser dog would not have survived this," Dr. Jackson said. "He touched everyone at the hospital."

"His disposition helped out a lot," Dr. Anderson said. "We could examine him and change bandages without using a muzzle or sedation."

Cassius has always been "a good, good dog," said owner Charla Basky. The family adopted him as a puppy. Because he's part boxer they named him after boxer Cassius Clay, who changed his name to Muhammad Ali when he joined the Nation of Islam. Though the little pup grew up to be a 97-pound dog, he has always been gentle, well-behaved and good with children. And that's why he was included in the family vacation.

Mrs. Basky was visiting her mother, Jackie Zinn, on her farm near Morgantown. With her and Cassius were daughter, Quintin, 5, and 3-year-old twins, Ethan and Madison. Dad stayed in Denver to work.

On Aug. 7, Cassius uncharacteristically chased a cat.

"We heard a yelp and thought the cat swatted him," Mrs. Basky said. "There was a little bit of blood on his face, but no wound."

The next day he was lethargic and his face was swelling so they took him to a veterinarian in West Virginia. A day later, the swelling was worse so they drove to Allegheny County to see the specialists. Veterinarians never found a puncture wound or any indication that snake fangs had pierced the dog's skin. The telltale skin sloughing started several days after he arrived in the hospital.

"Snakebites are rare around here," Dr Jackson said. "In Kansas, where I'm from, we see it more often."

Early on in his treatment, mother and children needed to return home, and Cassius' recovery would have been jeopardized on the three-day trip.

"I cried and cried on the drive back to Colorado," Mrs. Basky said. "I just asked them to please take good care of Cassius."

As he progressed, Dr. Jackson decided the family pet needed to spend some time in a regular home. She often took him to her home, which includes three dogs of her own. When Dr. Jackson determined that Cassius was well enough to go home in November, her husband, Ron, drove Cassius to Kansas to shorten the family's drive. The Basky family picked Cassius up there and drove him home.

On the dog's chest, neck and legs there are big patches of bare skin -- bright pink with black spots -- where hair did not grow back.

"This staff certainly went well above and beyond the call of duty," said Mrs. Basky, who is vacationing this month with family in West Virginia.

She and the staff declined to say what all that care cost, though Mrs. Basky said, "We'll be paying for the rest of our lives."

The staff and family discussed costs in advance and worked out a payment plan. The family got financial help from the Animal Care & Assistance Fund, a nonprofit "benevolent extension" of the center's work, according to its website, www.pvs-ec.com. The staff holds fundraisers and animal lovers donate to the fund to help pet owners pay big vet bills. Donations earmarked for Cassius were made to the fund, Dr. Jackson said.

Mrs. Basky presented the staff with a walnut plaque with a full-color picture of Cassius, and a brass plate with this engraved message:

"Thank you for all the love, attention and excellent care you gave Cassius. We thank you every day. The Basky Family & Cassius."

There were many smiles and a few tears when the tail-wagging snakebite survivor walked out the door.