Patient Stories / Case Studies

  • Photo: Internal Medicine

    Figure 1: An x-ray of Bryggen’s chest shows a mass within the trachea (red circle)

  • Photo: Internal Medicine

    Figure 2: During bronchoscopy, we visualized the mass obstructing 90% of the trachea

  • Photo: Internal Medicine

    Figure 3: The laser catheter (at the bottom of the screen) is cutting through the base of the mass to allow removal

  • Photo: Internal Medicine

    Figure 4: Two months after removal, only small scars remain at the site of the mass.

Photo: Bryggen


Bryggen, a 1.5-year old female spayed Bernese Mountain Dog was evaluated by the UC Davis Small Animal Internal Medicine Service for evaluation of lip-smacking behavior, wheezing, coughing, vomiting, and regurgitation. She had been seen by her local veterinarian on several occasions over the past 6 months for these episodes, but no abnormalities were ever found on examination. Multiple blood tests and x-rays had been performed without a diagnosis and there had been no resolution of signs with medication for infection and gastrointestinal reflux disease. Our physical examination was also unremarkable, and a swallowing study (x-ray ‘video’ of the swallowing process) was normal. Small feedings and new drug trials were instituted with minimal results.

At age 2, Bryggen returned to our hospital with a history of daily episodes of gasping, wheezing and open mouth breathing. At this appointment, her physical examination was again essentially normal, but we witnessed intermittent episodes of severe inspiratory wheezing associated with development of ‘blue’ gums, indicating that she was not receiving an adequate amount of oxygen to her lungs.

Neck and chest x-rays were repeated, and at this evaluation, a broad-based, irregular mass could be seen within the section of the trachea/windpipe that lies in the chest cavity (Figure 1). Because the mass was so close to the entrance to the lungs, surgical removal was considered dangerous. We decided to perform bronchoscopy (passing a camera down into the airways) to visualize the mass and collect samples that would tell us what cells were in the mass, and therefore whether or not it could be a malignant cancer.

During bronchoscopy, we encountered a large mass filling almost 90% of the trachea (Figure 2). This mass was incredibly firm and we were only able to obtain small biopsy samples using the scope. The pathology service informed us that the cells were most consistent with degeneration and proliferation of cartilage. While it was good news for Bryggen that the mass was unlikely to be a type of cancer, we still had to find a solution for removal of the mass that was obstructing her breathing. For help with this problem, we turned to colleagues in our Large Animal Clinic, who have specialized equipment designed to perform laser procedures in the upper airways of horses. Dr. Galuppo and colleagues reviewed the case with us and were eager to help. They recommended the use of a combination of cautery (a burning technique that can control bleeding and remove tissue) and laser energy to remove the tracheal mass. Fortunately for all of us, Bryggen was a large enough dog that we could use the same equipment used for horses!

Use of cautery or laser in the respiratory tract can be dangerous because of an interaction between the cauterization process and the high oxygen content of the air in the airways when a patient is under anesthesia. Prior to the procedure, we consulted with our Anesthesia Service to deliver a low oxygen mixture that would maintain Bryggen’s blood oxygen while reducing the likelihood of injury within the airways.

One week later, Bryggen returned to our hospital and was anesthetized. We passed the specialized endoscope from the equine department into the windpipe. A wire snare was passed through the endoscope, looped around the mass, and energy was applied to cauterize the base of the mass. At this stage, we passed a laser catheter into the windpipe in order to destroy the region of attachment of the mass to the windpipe (Figure 3). Within 3 hours, the mass had been removed.

The next day, Bryggen’s breathing was normal. We were all thrilled to receive the news that the biopsy was a benign mass of cartilage. Two months after the procedure, Bryggen was doing very well at home with no episodes of wheezing or respiratory difficulty. Repeat bronchoscopy revealed that the trachea had healed nicely at the site of mass resection and there was no evidence of regrowth (Figure 4).

Photo: Millie


Millie, a 5 year-old female spayed Maine Coon cat, was presented to the Internal Medicine service for evaluation of a life-long history of diarrhea. Ever since she was a kitten Millie had suffered from diarrhea. Initially it seemed to be controlled on antibiotics prescribed by her regular veterinarian, but now it was no longer responding, she was losing weight despite a ravenous appetite, and she was losing her fur.

By the time Millie reached us, she had gone from to 12.6 to 9.6 pounds, and she had constant diarrhea. Her fur coat was very thin, and she was weak.

Standard laboratory tests were performed to investigate the obvious causes of severe weight loss and chronic diarrhea but were within normal limits. An abdominal ultrasound suggested thickening of the intestinal wall and tests of intestinal absorption were abnormal. These changes made us consider the need to perform surgery to obtain biopsy samples. However, because Millie had suffered from this condition essentially since birth, we were concerned about a congenital problem and submitted a blood test to evaluate the digestive capacity of her pancreas. The pancreas makes and releases substances that start the breakdown of food for absorption by the intestines. This test was extremely low, and Millie was diagnosed with exocrine pancreatic insufficiency, a very rare condition in cats. Usually, cats with this condition also suffer from chronic pancreatitis and diabetes, but fortunately this was not the case with Millie.

Treatment for this disorder requires replacement of the digestive enzymes with either powdered or raw pancreas. Although Millie had a voracious appetite for virtually everything else, she disliked the pancreas supplementation. Fortunately, collaboration with a compounding pharmacy at UC San Francisco allowed us to create a formulation of this medication in gel caps that Millie would take with each meal. After 6 weeks on this medication, Millie's diarrhea had resolved, she was gaining weight, and her fur had returned to its normal luxurious state. 

Photo: Me-Too


Me-Too, a 2 year old female, spayed Cocker Spaniel dog was presented for evaluation of a 4 month history of a dry and hacking cough. Chest x-rays suggested bacterial pneumonia, but she had received several different types of antibiotics, and her cough worsened. She also lost her appetite and had less energy.

On presentation to the UC Davis Internal Medicine Service, Me-Too's physical examination revealed generalized harsh lung sounds and we noted that she used a lot of effort to exhale. We performed blood tests and chest x-rays to investigate Me-Too's condition.

Me-Too's blood tests revealed an elevation of eosinophils, a type of white blood cell that is often found with parasitic infections. We performed a heartworm test and several fecal examinations, because lung parasites can be coughed up and swallowed, and we can sometimes make the diagnosis from evaluating a stool sample. Me-Too's tests were all negative. Chest x-rays suggested worsening pneumonia so we anesthetized Me-Too and placed a bronchoscope down into her airways. A bronchoscope is a sheath of fibre-optic cables attached to a camera and light source. It allows us to visualize changes in the airways, to remove foreign bodies if present, and to collect fluid samples from the lining of the airways for analysis. Me-Too did very well throughout the procedure and her bronchosopy revealed severe inflammation throughout all of her airways along with large amounts of very thick, greenish mucus. We found large numbers of eosinophils in the airway fluid, but no parasites, and Me-Too was diagnosed with eosinophilic bronchopneumopathy. The cause of this condition is unknown, and because it does not involve a bacterial infection, antibiotics do not help. This condition requires relatively long-term treatment with corticosteroids (medications that control inflammation). Prior to using these drugs, it was critical to rule out an underlying bacterial infection, as steroids inhibit the body's ability to fight infection and can have serious side effects.

Me-Too's owners treated her at home with an oral corticosteroid, and within 5 days, Me-Too's cough had totally resolved and her activity level was increasing. To reduce any side effects associated with the drugs, we added treatment with an inhaled corticosteroid administered by a facemask and spacing chamber. By using inhaled products, we were able to gain control of her disease process without causing serious ill effects from the drugs. She continues to do very well. 

Photo: Meanie


Meanie, a 4 year old female, spayed domestic shorthaired cat was presented for evaluation of a foreign body in her trachea. Meanie was seen wretching after eating two days prior and was taken to her veterinarian. The veterinarian took x-rays of her chest and abdomen and saw a foreign body in the trachea and an additional foreign body in the stomach. Meanie was placed under anesthesia and her veterinarian attempted to retrieve the foreign objects out of the trachea but, unfortunately, was unsuccessful. As Meanie recovered from anesthesia, she vomited a rock. Meanie was then placed on an antibiotic and referred to us.

On presentation to the UC Davis Internal Medicine Service, Meanie's physical exam was within normal limits. We performed blood tests and chest x-rays to ensure that Meanie was healthy enough to be placed under general anesthesia again and to ensure that the foreign object was still present in her trachea. Meanie's blood tests were relatively normal, however her chest x-rays revealed two foreign bodies in the trachea that were suspected to be rocks. There was also evidence that Meanie might have pneumonia.

We anesthetized Meanie and placed a bronchoscope down into her airway. A bronchoscope is a sheath of fibre-optic cables attached to a camera and light source. It allows us to visualize any changes in the airways and to remove foreign bodies. Also, there is a channel within the scope that allows us to collect fluid samples from the lining of the airways for bacterial culture and analysis. We were able to visualize the first and later the second rock upon entering the trachea and were able to grasp and remove them using a four-prong grasper that fits down the bronchoscope. In addition, we found E. coli organisms in the airway fluid, indicating that an infection was present, likely from the rocks. Meanie was sent home the following day with continued antibiotics to treat her airway infection. She had no complications and recovered well from the procedure.

In Meanie's case, without the use of a bronchoscope to remove the rocks from her trachea, we would have had to subject Meanie to an invasive surgical procedure to remove the rocks. The bronchoscopy allowed us to quickly and easily remove the rocks from her trachea, with little recovery time needed for Meanie.

Photo: Pepper


Pepper, a 12 year old female, spayed terrier mix dog was presented for evaluation of a chronic, dry and hacking cough that was keeping everyone awake at night. Pepper had been adopted by the current owners 1 year ago when the previous owner (who was a long-term smoker) was debilitated by Alzheimer's disease. Pepper had been received various antibiotics to treat they cough but she had shown no improvement.

On presentation to the UC Davis Internal Medicine service, Pepper's physical examination revealed a sensitive trachea with induction of a harsh cough but her lung sounds were normal. Given her history, we were most concerned about the likelihood of chronic bronchitis (an inflammatory disease of the airways) or airway collapse as a cause for her cough. We also considered the possibility of a foreign body in the airways or a chronic infectious process. We performed blood tests and chest x-rays to investigate these possible diagnoses.

Pepper's blood tests and x-rays were relatively normal, and therefore, additional tests were required to determine the cause of her cough. We anesthetized Pepper and placed a bronchoscope down into her airways. A bronchoscope is a sheath of fibre-optic cables attached to a camera and light source. It allows us to visualize any changes in the airways and to remove foreign bodies. Also, there is a channel within the scope that allows us to collect fluid samples from the lining of the airways for bacterial culture and analysis. Pepper did very well throughout the procedure and her bronchosopy revealed remarkable changes in the diameter of her airways. We determined that she had marked tracheobronchial collapse. In addition, we found Bordetella organisms in the airway fluid, indicating that an infection was present. Bordetella is one of the organisms responsible for kennel cough, and most dogs are able to clear it from the lungs within 7-10 days. For some reason (perhaps because of the airway collapse), Pepper was unable to clear the infection on her own, and she required specialized therapy with inhalation of antibiotics.

Pepper's owners treated her at home with an antibiotic administered by an ultrasonic nebulizer attached to a facemask. Within 5 days, she showed an 80% reduction in her cough. We added in treatment with a bronchodilator to manage her airway collapse, and Pepper's cough was well controlled for 2 years.

Pepper's case provided us with several important lessons. Although Pepper was an older dog, she did very well throughout the anesthetic process for bronchoscopy, and the procedure was essential for determining her disease condition as well as the appropriate treatment. The bronchoscopy showed us that airway collapse was present and provided us with a rationale for using a bronchodilator. We also determined that infection with Bordetella can be a cause for chronic cough, that it does not always respond to oral antibiotics, but that nebulization with antibiotics can reduce clinical signs.

Photo: Lucy


Lucy, a 10 year old female spayed Catahoula hog dog. Lucy presented to her local veterinarian with a 2-day history of lethargy, reluctance to jump down from the owner's truck, and decreased appetite. She lived on a produce farm, had possible access to antifreeze, and also has access to freestanding water. She receives daily anti-inflammatory drug therapy for osteoarthritis. She had no history of tick exposure, traumatic injuries, or travel outside California. A physical examination performed at her local veterinary clinic revealed no significant abnormalities. Bloodwork showed that Lucy was in kidney failure. She was treated with intravenous fluids and antibiotics, but upon discharge from the hospital she began vomiting and was returned to her local veterinarian. Further bloodwork showed that her kidney failure was worsening and so she was referred to the UC Davis VMTH.

At the VMTH, Lucy was found to be depressed, dehydrated, and she had a slightly painful abdomen. Bloodwork showed severely elevated kidney values and mild elevation in her liver enzymes, and evaluation of a urine sample showed evidence of acute kidney damage. An ultrasound of her abdomen showed that her kidneys were slightly larger and brighter than normal. Based on her history and clinical findings, Lucy was suspected to have acute kidney failure due to leptospirosis. Lucy was treated aggressively with intravenous fluids, intravenous nutrition (TPN), diuretics to stimulate urine production, antacids, drugs to control her vomiting and abdominal pain, and antibiotics that are known to destroy leptospires. Subsequently, the results of diagnostic testing for this disease confirmed leptospirosis as the cause of Lucy's illness.

Lucy's urine output subsequently increased dramatically and her fluid therapy was carefully adjusted to prevent dehydration. Her kidney values gradually declined to normal levels over the 2-week period of hospitalization. Towards the end of her stay an esophageal feeding tube was placed under anesthesia so that intravenous nutrition did not need to be continued. Several days after she was sent home she began eating on her own and the tube was removed. Lucy was incontinent for several months after she was discharged from the hospital, and this was managed with drugs to control her incontinence. Six months later, Lucy's kidney function is normal, she is no longer incontinent, and she is enjoying life back on the farm.

Leptospirosis is a disease caused by a spiral bacteria, Leptospira interrogans. The bacteria is shed in the urine of domestic and wild animals, and survives in free standing water sources and urine saturated soil. In California, dogs are commonly infected in the winter following heavy rainfall when they drink from contaminated water sources. Humans can also become infected and can show signs ranging from an influenza-like illness to severe neurologic signs, bleeding into the lungs, and kidney and liver failure. Most people in the United States are infected following recreational activities involving water, and outbreaks have followed activities such as triathlons. Affected dogs in California often develop severe kidney failure, sometimes requiring hemodialysis. Although Lucy did not require hemodialysis, the UC Davis VMTH is fortunate to have a hemodialysis unit such that dogs with severe leptospirosis can be cured. The hemodialysis procedure removes toxic wastes such that the kidneys can be given time to heal and the bacterial infection can be treated with appropriate antibiotics.

Studies are underway at UC Davis VMTH to determine the true strains of leptospires that infect dogs and how infection of dogs impacts human and wild animal health.