'Mucosal bands' in feline intestines

On abdominal ultrasound, feline intestines may occasionally display thin, linear hyperechoic lines coursing within the mucosa, parallel to the submucosa. These 'mucosal bands' are a recognized ultrasonographic finding in cats and are most consistently associated with mucosal fibrosis. Histopathology shows that they may represent fibrotic remodeling of the intestinal lining, often reflecting a chronic, ongoing disease process — though in some cats they can be an incidental finding.

Pathophysiologic significance

Mucosal fibrosis develops as a consequence of long-standing intestinal inflammation. In cats, it is most frequently encountered in the setting of chronic enteropathy, particularly lymphoplasmacytic enteritis. This fibrotic change alters normal mucosal structure and is responsible for the distinct linear hyperechogenicity observed sonographically.

Clinical context

Mucosal bands are not pathognomonic. They have been described in cats with chronic gastrointestinal signs — vomiting, diarrhea, weight loss, anorexia, or combinations thereof — where they should raise strong suspicion of chronic enteropathy. However, studies have also documented their occurrence in clinically healthy cats, meaning that the finding alone does not equate to disease. Their clinical significance must therefore always be interpreted in the context of history, clinical signs, and other diagnostics.

Diagnostic value

In symptomatic cats, mucosal bands are considered a useful non-invasive marker of chronic disease. They can indicate a long-standing condition and support the decision to pursue further diagnostics or targeted treatment. However, they do not differentiate between types of chronic enteropathy and cannot rule out intestinal lymphoma.

Gold standard confirmation

Despite their diagnostic utility, histopathology remains essential. Endoscopic or full-thickness intestinal biopsy is required to confirm fibrosis, characterize the underlying inflammatory infiltrate, and reliably differentiate chronic enteropathy from intestinal lymphoma, which can mimic similar ultrasonographic changes.