Functional dyspepsia: from human to dog, a retrospective study of 29 cases illustrating a complex entity

Functional gastrointestinal disorders, including mostly functional dyspepsia (FD) and irritable bowel syndrome, are highly prevalent in human patients. FD is a complex condition in human gastroenterology and is characterized by abdominal discomfort, epigastric pain or burning, postprandial fullness, or early satiety. To our knowledge, such a syndrome, in the absence of organic, metabolic, or systemic causes, has not been reported in dogs. We aimed to provide a comprehensive description of the presentation of suspected canine functional dyspepsia in a retrospective case series. All records of dogs suspected of having dyspeptic clinical signs were studied. Laboratory data, imaging results and gastroscopic findings unlikely to explain the intensity of clinical signs were mandatory for inclusion.

Twenty-nine dogs were retrospectively enrolled. All presented with signs of gastrointestinal discomfort but results from bloodwork, abdominal ultrasonography, endoscopy, and histopathology did not fully account for the severity of the clinical signs observed. FD was found to predominantly affect females (66%) and was most associated with vomiting (97%), abdominal pain (58%), intermittent diarrhoea (52%), pica (52%), compulsive chewing behaviours (48%), and belching or excessive yawning (41%), along with other signs of upper gastrointestinal discomfort. The median duration of clinical signs was 1.5 years, with a median age of onset also at 1.5 years. Various treatments were attempted with varying success, including dietary changes, antacids, prokinetics, and steroids. Follow-up data were available for 21 dogs, of which 76% demonstrated clinical improvement over a median follow-up period of 12 months. Interestingly, anxiety disorder of the owner was commonly reported.

Functional dyspepsia is a clinically emerging functional gastrointestinal disorder in dogs, especially in toy and small breed, middle-aged, female dogs, characterized by chronic gastrointestinal discomfort and vomiting in the absence of confirmed organic disease. The clinical picture of intense abdominal crisis with highly involved and anxious owners is out of step with the results of investigations. Overlap with food-responsive enteropathies, immunosuppressant-responsive enteropathies, or gastroduodenal dysmotility disorders is still of concern, potentially triggered by emotional disorders. Canine FD could reflect a gut-brain axis disturbance and should be included in the differential diagnosis of refractory canine upper digestive disorders. Tailored therapeutic approaches, including dietary modifications, antacids, and prokinetic agents, may offer clinical benefit.