Case 5 California Sea Lion

1. CharmaneThurmand Shauna Decker Aaron Clark Sarah Glazier Case 5California Sea Lion

2. Phylogenetic/Taxonomic Placement: Order: Carnivora Family: Otariidae Genus: Zalophus Species: Z. californianus • Range: • Found from Mexico north through California to British Columbia. • Live along the coast and up to ten miles out to sea Info about Sea Lions

3. Interesting facts • Average lifespan 17 yrs (in wild) • Seal nose shut to stay under water up to 15 min • Travel at average speed of 10.8 km/hr = 6.7 mph • Swim at speeds of 2.7 m/s or 8.8 ft/s • Diet includes variety of seafood, mainly squid and fish. Will cooperate with sharks, dolphins and seabirds when hunting large schools of fish • Intelligent, trained easily More info

4. A young stranded California Sea Lion admitted to a rehabilitation center in June. • Emaciated • Diarrhea • High white blood cell count (Neutrophilia) • Elevated levels of protein and albumin • Decrease in blood urea nitrogen concentration • Determined to be dehydrated and malnourished Case Background

5. Two Weeks Later • Anorexic • Blood/mucus around oral cavity • Corneal opacity in right eye (transparent structure on front of eyeball. Occurs when cornea becomes scarred) • Leukocytosis (raised white blood count with larger ratio of immature neutrophils to mature neutrophils) • Anemia (deficiency of hemoglobin in red blood cells) • Thrombocytopenia (relatively few blood platelets in blood) • Died two weeks after admission, and necropsy performed Case cont.

6. Hemorrhaging in lung lobes • Swollen and damaged arteries • Interstitial Pneumonia with scarring • Lungs contaminated with Escherichia coli • Pus present • Clotting in pulmonary blood vessels • Enlarged/hemorrhaged lymph node • Blood-tinged mucus in trachea and bronchi • 150 nematodes collected from the pulmonary arteries • Two nematodes found in right ventricle of the heart • Nasopharyngeal acariasis (mites in nose and throat) • No parasitic cysts or Helminth eggs/larvae found in fecal samples Post Mortem

7. Nematodes were present within the lungs along with the greatest amount of bodily harm. • Possible Nematode Infections affecting the lungs • Lungworm (Nematoda: Metastrongyloidea) • Attachment blocks airways, induces mucus production, and can lead to secondary bacterial infections, • Lungworm (Parafilaroidesdecorus) • Hyperemia (excess blood), hemorrhaging, cellular infiltration, verminous pneumonia • “Lungworms are common in all pinnipeds [marine mammals). Sea lions have Parafilaroidesdecorus , while true seals are usually parasitized by Otostrongyluscircumlitus . The latter parasite is also found in the hearts of some phocids [seals, sea lions, etc]; however, it does not produce a microfilaremia. Both of these parasites use fish as intermediate hosts.” (Thanks Merck Veterinary Manual) Hypothesis • http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/170810.htm

8. Otostrongylus circumlitus • Although typically affecting true seals, the symptoms for this particular nematode fit with the information given in the case. • Mucus and blood around the oral cavity and within the trachea • Internal hemorrhaging (from attachment?) • Secondary E. coli infection in the lung What we think it is

9. Metastrongyloid Nematode (Otostrongylus circumlitus) Actual Infection

10. Question • What is the host of Otostrongylus circumlitus? • Answer • True seal’s Exam Question