Adipose tissue torsion with localized lymphangiectasia in a Rio Cauca caecilian Typhlonectes natans.

Abstract

A female Rio Cauca caecilian Typhlonectes natans (estimated as between 10 and 18 years of age) housed at the Smithsonian National Zoological Park in Washington, D.C., developed progressive severe coelomic effusion over a 4-week period. The coelomic effusion was diagnosed via radiographs and ultrasound, and a sample of the fluid was obtained for analysis, which revealed a low-protein transudate suggestive of inflammation. As the coelomic effusion progressed, the caecilian became tachypneic, hyporexic, and lethargic. The caecilian was started on antibiotics and a diet trial, but signs continued despite therapy. An exploratory celiotomy was performed, which revealed adipose tissue torsion with local lymphangiectasia and a presumptive biliary cyst. Surgical correction was unable to be achieved due to concern for fatal hemorrhage, as the vasculature associated with the torsion was severely distended. Due to the severity of the torsion and associated risks, the caecilian was euthanized intraoperatively and subsequently necropsied for histologic evaluation. After reviewing the caecilian's presentation and the progression of disease, it is suspected that the severe coelomic effusion was secondary to lymphangiectasia, which occurred subsequent to the adipose tissue torsion. This is the first reported case of adipose tissue torsion and associated clinical disease in an aquatic caecilian and should be a differential for progressive coelomic effusion in this species.