Estimated reading time: 7 minutes
A 14-month-old male neutered golden retriever was referred to The Pet Specialists’ Aerodigestive Health Centre for investigation of recurrent aspiration pneumonia. In the preceding months, the dog had experienced several bouts of coughing that improved with antibiotics but returned shortly after treatment ceased. He had been treated with several courses of amoxicillin-clavulanic acid (at appropriate doses) and then escalated to enrofloxacin on multiple occasions. His owner also reported intermittent night-time restlessness, excessive swallowing after exercise and occasional gagging episodes.
Clinical examination and initial investigations
Physical examination was unremarkable, with normal body condition and no overt respiratory signs at the time of assessment.
A complete blood count, serum biochemistry, total T4, ACTH stimulation test, and serum cobalamin were all within normal limits. Abdominal ultrasound revealed no significant abnormalities.
Three-view thoracic radiographs demonstrated consolidation in the ventral aspect of the caudal segment of the left cranial lung lobe which was consistent with resolving aspiration pneumonia, as well as increased gas opacity in the region of the thoracic oesophagus. These findings raised suspicion of an underlying oesophageal disorder contributing to the recurrent aspiration events.
Advanced diagnostic imaging—videofluoroscopic swallow study
A videofluoroscopic swallow study (VFSS) was performed using a standardised feeding protocol to evaluate dynamic swallowing function in real time. This test has become the criterion standard for diagnosing dysphagia and aerodigestive disorders in dogs. The study revealed variable air accumulation within the thoracic oesophagus, particularly between the cardiac silhouette and gastric cardia. During the oesophageal phase, the dog demonstrated poor bolus formation and multiple isolated ring-like contractions without organised peristaltic waves.
Persistent segmental oesophageal distension containing contrast material was noted. Several episodes of gastro-oesophageal reflux were observed. A small amount of contrast reached the larynx and epiglottis, consistent with aspiration risk, although no contrast entered the lungs during the study.
These findings were diagnostic for generalised oesophageal dysmotility with secondary oesophageal dilatation (megaoesophagus) and recurrent reflux events, collectively contributing to the dog’s chronic and recurrent aspiration pneumonia. An acetylcholine receptor antibody titre was within the reference range.
As such, the dog was diagnosed with generalised oesophageal dysmotility and megaoesophagus and recurrent aspiration events, with concurrent gastro-oesophageal reflux disease and impaired airway protection mechanisms.
Aerodigestive disease: a broader perspective
Aerodigestive disorders (AeroDs) encompass a spectrum of conditions where dysfunction of the digestive and respiratory tracts overlap. They arise from abnormalities in swallowing, reflux or airway protection that allow material from the oropharynx or stomach to enter or irritate the respiratory tract.
While aspiration pneumonia is the most recognised manifestation, the underlying aerodigestive dysfunction is often underdiagnosed. Research has shown that dogs with AeroDs frequently present with respiratory disease in the absence of overt gastrointestinal signs, and thoracic radiographs may appear normal.
Common risk factors include oesophageal dysmotility, vomiting, regurgitation, neurologic disease, laryngeal dysfunction and brachycephalic airway obstruction. Importantly, chronic aspiration can perpetuate a vicious cycle of inflammation, infection and structural airway damage, leading to progressive loss of pulmonary function.
Pathophysiology and clinical relevance
In health, swallowing and respiration are tightly coordinated to protect the airways. During swallowing, the larynx elevates, the epiglottis closes, and breathing temporarily ceases to prevent aspiration. In dogs with oesophageal dysmotility or reflux, these defences are compromised. Refluxate containing acid, pepsin, and bile salts causes local irritation of the oesophagus, pharynx and larynx leading to inflammation and dysfunction.
Chronic exposure can also induce airway hypersensitivity and secondary respiratory disease. Studies in both human and veterinary medicine demonstrate that treatment of reflux can reduce respiratory exacerbations and improve clinical outcomes.
Treatment and management
Management of aerodigestive disorders is tailored to the underlying pathology. In this case, therapy was directed toward reducing reflux events and supporting oesophageal clearance. The dog was transitioned to an upright feeding regimen with a Bailey chair constructed by the owner, with food and water offered from an elevated position.
The VFSS was able to help determine the ideal food consistent to aid transit. A low-fat diet was also recommended to aid gastric emptying and reduce gastric volume after meals that could exacerbate GERD.
Medical management included the use of a proton-pump inhibitor to reduce gastric acidity. The aspiration pneumonia was also treated with appropriate antibiotics. We also advised using a donut collar for sleeping to reduce aspiration events during the night when asleep.
Outcome and follow-up
At six-month follow-up, the dog remained clinically stable with no recurrence of aspiration pneumonia. The owner reported marked improvement in sleep quality and reduced coughing. Occasional regurgitation persisted but was easily managed with feeding modifications.
This case highlights the importance of recognising aerodigestive disease as an underlying cause of recurrent aspiration. The use of VFSS was pivotal in establishing the diagnosis and guiding management.
Why aerodigestive disorders matter
Aerodigestive diseases are increasingly recognised as a major cause of chronic respiratory signs in dogs, yet they often go undiagnosed without advanced imaging. Because clinical signs may be subtle, such as night-time restlessness, repetitive swallowing, or lip licking, these cases can easily be mistaken for primary respiratory infections or allergies.
The Aerodigestive Health Centre at The Pet Specialists is dedicated to identifying and managing these complex conditions through a multidisciplinary approach combining internal medicine, radiology, and surgery. By assessing swallowing and airway function in tandem, clinicians can uncover hidden contributors to chronic respiratory disease and develop targeted treatment plans that reduce recurrence and antibiotic use.
Dr Elizabeth Thrift BVSc (Hons) FANZCVS
The Pet Specialists’ Aerodigestive Health Centre
Terrey Hills, NSW
Dr Thrift graduated from the University of Sydney in 2007. While working at a small animal general practice in Sydney, she was mentored by a then-leading feline medicine specialist in Australia who encouraged her to pursue veterinary specialist training. She subsequently undertook a multi-disciplinary internship at the Small Animal Specialist Hospital (SASH) in 2011 where she subsequently remained to continue her specialist training.
She started working for The Pet Specialists in 2017.
In addition to her clinical role, Dr Thrift is deeply committed to advancing the veterinary profession through education and mentorship. She currently serves as president of the Small Animal Internal Medicine Chapter of the Australian and New Zealand College of Veterinary Scientists (ANZCVS), where she leads initiatives that shape the future of veterinary care. She has also been an examiner in small animal medicine for ANZCVS and co-chair of the ANZCVS small animal medicine fellowship (specialisation) examination committee.
Her clinical interests include immune-mediated diseases (e.g. IMHA and IMT), as well as gastrointestinal, liver, pancreatic, and gallbladder diseases, and aerodigestive disorders.
