Hydrocoelom and lymphedema in dendrobatid frogs at National Aquarium, Baltimore: 2003-2011

Hydrocoelom and lymphedema are common in amphibians. In the family Dendrobatidae at the National Aquarium, Baltimore, prevalence was 3.19% from 2005 to 2011. Complete review of all cases in dendrobatids from 01 January 2003 to 01 June 2011 at the National Aquarium identified annual incidence rate, associated signs, diagnostic findings, therapeutics, and outcomes using medical record review. Associated etiologies were assessed via available necropsy and histopathology reports. Hydrocoelom was defined as coelomic distention with fluid; lymphedema was defined as fluid accumulation in the lymph spaces. These two syndromes could occur concurrently, and no association between case success (36.5% overall) or etiology was found to contrast hydrocoelom and lymphedema. Species susceptibility varied, with increased prevalence and incidence rate in Adelphobates castaneoticus, Dendrobates auratus, and Phyllobates spp. D. auratus also had reduced case success overall (26.0%). Females experienced hydrocoelom and/or lymphedema at an attack rate more than three times that of males. Fluid aspiration for culture was the most predictive antemortem diagnostic to find infectious etiologies, but antemortem diagnostics were largely noncontributory in identifying other causes of fluid accumulation. Enrofloxacin treatment increased case success more than fivefold when compared to those not treated and was the only treatment positively associated with case success. Infectious etiology, renal disease, and gastrointestinal disease, including parasitism, were seen commonly on postmortem evaluation of cases. These findings underscore the importance of the ability to individually track and treat cases, with fluid culture and initiation of enrofloxacin therapy (10 mg/kg p.o.q. 24 hr) seen as the best first steps after presentation with hydrocoelom or lymphedema.