Fatal Branchitis with Acute Systemic Inflammatory Response Associated with Gill Nematodiasis in Bowmouth Sharks (Rhina ancylostoma)
We report on two bowmouth sharks (Rhina ancylostoma), housed at uShaka Sea World, Durban, that presented with toxic clinical signs following routine praziquantel bath treatments in their enclosure. Treatment was instituted, but ultimately unsuccessful. Other benthic elasmobranch also showed mild clinical signs, but recovered uneventfully without requiring any treatment. A post mortem showed signs of generalised inflammation and toxicity. A heavy nematode larvae infection was observed in all branchial arches. Histopathology confirmed a severe branchitis with moderate numbers of melanomacrophages and numerous cross sectional segments of nematode parasites. The gills furthermore revealed thrombosis of many brachial vessels in the inflammatory zone. Glomerulonephritis was found and thought to be as a consequence of excessive antigen-antibody complex formation due to chronic antigenic stimulation. One of the animals also revealed acute degenerative myopathy with muscle protozoa.
We are identifying the parasites using both molecular and morphological tools and will report on our findings.
* Presenting author