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NORTH AMERICAN FAUNA 68 



mon parasite of sea otters, you surely would have noticed it, especially in 

 captive animals. 



I have examined many sea otters and found no external parasites 

 other than nasal mites (Halarachnidae). Although these are techni- 

 cally ectoparasites, they are found within the nasal passages. As 

 pointed out previously (Kenyon, Yunker, and Nev^ell, 1965), 

 infestation of the sea otter v^ith Halarachne miroungae is probably 

 fortuitous. The only massively infected animal (over 3,000 mites) 

 was a captive that was held under abnormal conditions in a fresh- 

 water pool. Infestation in the wild appears to be insignificant. 



Enteritis 



The following discussion presents observations obtained at 

 Amchitka Island and information contributed by M. C. Keyes, 

 D.V.M., Bureau of Commercial Fisheries. 



Enteritis is frequently observed as the terminal symptom at 

 death in sea otters at Amchitka. It is similar to the entero toxemia 

 found in the fur seal, harbor seal, and certain domestic animals. 

 A Clostridium organism has been isolated and identified from a 

 fur seal. Keyes (1963) uses the name necrohemorrhagic enteritis. 

 The symptoms observed in the sea otter are quite similar to those 

 observed in lambs and other mammals. 



Symptoms exhibited by sea otters found on Amchitka beaches 

 are listed: 



1. The animal may be unable to stand or walk. 



2. It may appear semicomatose or very lethargic and fearless. 



3. It often exhibits hiccup-like convulsions. 



4. The vibrissae may be extended rigidly forward. 



5. The necropsy reveals intestinal lesions of variable extent. 

 Young animals may die while lesions are small, affecting 3 to 4 



inches of the small intestine. The intestine is inflamed, muscle 

 tone is lost, and affected areas become blackish or greenish black 

 in color. In adult animals, long sections of the small intestine show 

 this condition at death. The colon has not been specifically observed 

 to show the extensive lesions found in the small intestine. 



The small intestine and colon often contain the remains of about 

 a dozen small sea urchins. Black tarry feces may or may not be 

 voided before death. In young animals particularly, the progress 

 of enteritis to death may be rapid. 



6. Death may occur before the typical black fecal matter is 

 voided. The black condition of the feces is called melena (a com- 

 bination of the iron found in hemoglobin and hydrogen sulfide to- 



