Computed Tomography Findings in Three Cases of Suspected Lymphovenous Communications in Cats

Pathological lymphovenous communications are poorly characterized in veterinary medicine, and their computed tomographic features and clinical significance remain unknown. This retrospective case series aimed to describe contrast-enhanced computed tomography findings of suspected spontaneous lymphovenous communications in three cats. All cats had dilated, tortuous vessels arising from portal venous tributaries and extending to the cisterna chyli, originating from the splenic vein in two cats and the cranial mesenteric vein in one. The cisterna chyli and thoracic duct were consistently dilated and contrast-enhancing, and reduced portal vein calibre cranial to the communications was present in all cats. Concurrent findings included pleural or peritoneal effusion and subcutaneous edema, with chylous pleural effusion confirmed in two cats. The recurrent anatomical distribution and associated portal and lymphatic abnormalities suggest that these communications may represent the enlargement and functional recruitment of pre-existing lymphovenous pathways in response to acquired portal and/or lymphatic hemodynamic disturbances, although a congenital origin cannot be excluded. Contrast-enhanced computed tomography may allow the recognition and anatomical characterization of suspected pathological lymphovenous communications in cats and should be considered when anomalous portal vessels are associated with concurrent cisterna chyli and thoracic duct abnormalities.