As the rings of cartilage that braced his trachea began breaking down, Jack, a 12-year-old Yorkshire terrier, could be heard wheezing and “honking” with increasing frequency. Later he had episodes of lethargy and lost interest in exercise. As his condition grew worse, Jack’s tongue and gums took on a bluish hue. By the time he arrived for treatment at MU’s Veterinary Hospital, he was so starved for air that he had to be carried to an examination room.
Jack was diagnosed with “tracheal collapse,’ a condition distressingly common among so-called toy breeds. Its cause is not yet known, but veterinary scientists suspect a congenital defect in the cell structure of tracheal cartilage may be at least partly to blame.
For most dogs, a combination of drug treatments, weight management and behavioral modifications is enough to control the worst of their symptoms. But because the condition is degenerative, these interventions become less effective over time. For dogs at the severe-symptom stage, like Jack, a surgical procedure — one that implants polypropylene stabilization rings around the compromised section of trachea — has long been their last, best hope. But the operation is difficult and prone to complications. Even successful surgeries rarely return a pet to anything resembling normal levels of activity.
Thankfully, Jack and his owner had additional options. Veterinary specialists such as MU’s Carol Reinero have for the past decade or so made great strides in deploying intra-luminal tracheal stents to prop up collapsed airways. These stents, typically made of what their manufacturer calls “a thermal-shape-memory nickel-titanium alloy,” expand to conform to the shape of a dog’s windpipe, or tracheal lumen, after they are inserted.
The operation takes fluoroscopic equipment and a skilled team to perform. Participants include an internal medicine specialist who assesses the patient’s overall respiratory health, places the stent and performs long term follow-up; a veterinary anesthesiologist who handles the complicated anesthesia requirements; and a veterinary radiologist who runs the fluoroscopy unit and helps guide placement of the stent. No incision is required. MU’s Veterinary Hospital is the only facility in the state that offers the procedure.
“The procedure is generally considered a last-ditch effort,” says Reinero, an associate professor of small animal internal medicine who has been performing it since joining the MU faculty in 2004. “It takes a great deal of planning and precision. But its success can be seen — and heard — almost immediately.”
And so it was for Jack. Two weeks after the operation, a follow-up examination showed that his oral membranes had returned to a healthy pink color. His tracheal and lung sounds were normal. The radiographs showed formerly compromised tracheal areas now propped fully open.
“When Jack first came to us, he was wheezing and coughing, and we had to carry him around because of his condition,” said Heather Wise, a fourth-year veterinary medical student. “At his follow-up, we didn’t even hear him coming down the hall for his appointment.”
The treatment is expensive, and not all patients respond as well as Jack. Even those patients that do well require careful post-operative care, including medications to reduce coughing and mucus build-up. Still, for dog lovers like Connie Miller, Jack’s owner, the stents and follow-up have been more than worth it.
“We didn’t realize how serious his condition was, but it was a great relief to know that it could be treated,” says Miller. “He can now run around in the yard. This means everything to me. Jack is my little friend.”