Hydrocoelom and Lymphedema in Dendrobatid Frogs at the National Aquarium, Baltimore
Hydrocoelom and lymphedema are common in amphibians.1,2 A retrospective review of these syndromes in Dendrobatidae at the National Aquarium, Baltimore, from January 1, 2005 to December 31, 2010 was performed. Hydrocoelom was defined as coelomic distention with fluid; lymphedema was defined as fluid accumulation in the lymph spaces. Clinical signs, diagnostics, therapeutics, and outcome were assessed. Available necropsy and histopathology information was also assessed.
Seventy-five affected individuals from two genera were identified (Dendrobates and Phyllobates spp.), with high prevalence of D. auratus (n=27). Nine cases presented as mortalities or were immediately euthanatized. Aspirates performed in 56.0% of individuals (n=37/66) identified bacteria in 54.0% of cases (n=9 cytology, n=13 aerobic culture, n=2 both) and correlated with histopathology completed on mortalities. Treatment protocols changed over time. Earlier cases were generally treated with immersion in hyperosmolar solutions and topical antibiotics. More recent cases were generally treated with furosemide (2–5 mg/kg PO q 24–48 h) and systemic antibiotics.
Overall, 28.0% of individuals survived six months or longer without clinical signs (n=21/75). Early response to treatment appears predictive of long-term success, and preliminary analysis suggests more recent cases had improved survival. On histology, renal pathology was identified in 66.7% (n=14/21) of submissions including renal cysts, nephrosis, and interstitial nephritis. Due to underlying pathology, hydrocoelom and lymphedema carry a guarded prognosis in dendrobatids. Therapeutic protocols including systemic antibiotics and diuretics offer the best chance at clinical resolution.
1. Pessier AP. Edematous frogs, urinary tract disease, and disorders or fluid balance in amphibians. J Exotic Pet Med. 2009;18:4–13.
2. Vannevel JY. Glomerulonephritis and anasarca in a colony of frogs. Vet Clin North Am Exot Anim Pract. 2006;9:609–616.