What's The Diagnosis? - Case 3 - Tissue from a Swan

[@maxhughes2590]

Another terrific presentation. Many thanks. How does the nematode enter the bird's heart? Is it via the blood?

[@DownTheScopeMicroscopy]

Good question! I realised after recording that I'd failed to talk about the parasite much. Apparently this is Sarconema eurycerca, a filarial nematode. The females live in the circulation (probably in veins in this case) and release larvae called microfilaria into the circulation. The microfilaria are ingested by an ectoparasite (mosquitoes or midges) and transferred to a new host where they enter the circulation and mature into adults. This is similar to more common mammalian parasites like the dog heartworm (Dirofilaria immitis).