Family credits antibiotic with saving their dog's life amid mystery respiratory illness

As cases of serious respiratory illness affecting dogs remain on the rise across the country, one family is sharing how an antibiotic helped their dog survive.

Becky Oliver of California told "Good Morning America" her family's 5-year-old golden retriever, Ike, rapidly developed an alarmingly high fever in September while traveling to compete in dog shows.

"He really didn't exhibit any symptoms at the beginning, maybe a cough here or there," she told "GMA." "When they took his temperature at the emergency vet hospital in Arizona, they said his fever was 105.3. His color wasn't good."

To date, the unknown illness impacting dogs like Ike has been reported in multiple states, including Oregon, California and Colorado.

While research is underway, veterinarians say the mystery illness is highly contagious and in severe cases can be fatal. Reported symptoms so far have also been typical of kennel cough: They include coughing, sneezing, nasal and/or eye discharge and lethargy.

Becky Oliver said Ike's condition later developed into pneumonia, forcing him to spend multiple days in a veterinary hospital.

At one point, Becky Oliver said her family was told by the medical team that they did not think Ike was going to survive the illness.

She said she saw a glimmer of hope after learning about an antibiotic called chloramphenicol, which could be a potential treatment for the unknown disease.

"The vet at first was like, 'Oh, no, no, that's an extremely strong antibiotic, kind of a last-ditch effort antibiotic,'" she recalled. "And then the internal medicine veterinarian came over and said, 'No, let's try it.'"

According to Becky Oliver, 12 hours after Ike received the first dose of the medication, he was weaned off oxygen and able to return home later that week.

Becky Oliver's husband John Oliver told "GMA" their family's beloved dog is now back to his normal self.

"He looks great ... He's jumping around," John Oliver said. "We still can't believe he's still here."

Dr. Lindsey Ganzer, a veterinarian and the owner of the North Springs Veterinary Referral Center, described chloramphenicol as an "incredibly powerful antibiotic."

Ganzer, who did not treat Ike, confirmed the medication is most often used as a "last resort" option.

"That particular antibiotic is typically used as a last resort," Ganzer told "GMA." "It is one where, you know, if we give it to an owner to give to a dog, they have to handle it with gloves because people can't really touch it."

Ganzer said she recommends dog owners stay away from boarding or bringing your dog to an environment with other dogs, at least temporarily.

"[The] most important thing is to avoid any areas where there are a lot of dogs in that space. So, avoid boarding them. Avoid doggie day cares, going to the groomer, going to dog parks," Ganzer said.

Ganzer added that if owners do see their pets exhibiting symptoms of the mystery illness, they should isolate the dog and then seek medical attention.

"We don't know how it's spread, whether it is direct contact or whether it is through the air. If your dog is symptomatic, definitely get seen by a veterinarian sooner rather than later," Ganzer said. "The earlier that treatment starts, the better chance they have of not progressing and developing into a pneumonia."