Since its inception, the Karen C. Drayer Wildlife Health Center has been deeply involved in critical research on the health and conservation of southern sea otters (Enhydra lutra nereis) and other marine mammals in California. All of this work has been conducted in close collaboration with researchers, wildlife managers and coastal stewards, including governmental agencies and non-governmental conservation agencies. In addition to publishing dozens of studies on the epidemiology and pathobiology of diseases affecting southern sea otters, the WHC has dedicated significant time and effort in sharing information with policy makers and raising awareness among stakeholders.
Among many important lines of inquiry, WHC faculty, staff and students have conducted research showing that pathogens such as Toxoplasma gondii, Sarcocystis neurona, Cryptosporidia spp,, Giardia spp. and a host of bacterial pathogens cause disease in California marine mammals. Toxoplasma gondii research in particular has been foundational for the WHC: it is a tiny parasite that lives in the bodies of many people and animals. Most people with Toxoplasma gondii (Toxo) never show any symptoms of illness; however, infection in pregnant women can cause birth defects, including blindness and brain damage).
Cats are the definitive hosts that spread Toxoplasma to other animals and people, although they never develop disease associated with their infections. Cats can shed millions of oocysts for 7-14 days the first time they get infected. The oocysts live in the soil and water, are spread by earthworms, flies and beetles, and are picked up by other animals. Based on WHC research, we now know that these oocysts are making their way into the ocean, and that otters are infected through ingestion of prey that have taken up the oocysts in the gastrointestinal tracts or tissues.
For more about the health threats facing southern sea otters --- much of this knowledge stemming from research conducted by the WHC and collaborators – see HERE.