Erythrocytic inclusion body syndrome (EIBS) was artificially
established in selected stocks of juvenile fall and spring chinook
salmon (Oncorhynchus tshawytscha), chum salmon (0. keta), coho
salmon (0. kisutch), Atlantic salmon (Salmo salar), and rainbow
trout (0. mykiss). Adult spring chinook salmon were also
artificially infected with the EIBS virus. Adult male chinook had
higher prevalences of EIBS inclusion bodies than females.
Cytoplasmic inclusion bodies that are associated with EIBS were
not observed in steelhead (0. mykiss), brown (Salmo trutta) nor
brook (Salvelinus fontinalis) trout suggesting that these stocks are
less susceptible to the EIBS virus.
Coho salmon with EIBS were more susceptible to Flexibacter
psychrophilus, the causative agent of cold water disease (CWD)
than fish without EIBS. The fish with EIBS were most susceptible
to F. psychrophilus during the first 20 days after virus exposure,
when inclusion bodies were most prevalent. Coho salmon infected
with both the EIBS virus and F. psychrophilus required a longer
recovery period than fish exposed to either pathogen alone.
Most investigations of EIBS require in vivo experimentation
and artificial infections using diseased fish tissues. Heterologous
tissue used to establish EIBS did not contribute to anemia nor
mortality. Death was not attributed to the EIBS virus alone but to
the combined effects of the virus and a secondary pathogen.
The severity of EIBS may be reduced with dietary Vitamin C
prophylaxis. Fish fed 1,000 mg ascorbic acid/ Kg of diet had the
fewest signs of EIBS; they had the highest hematocrit values and
the lowest incidence of cytoplasmic inclusion bodies. However,
vitamin C therapy alone was not sufficient to prevent the disease. / Graduation date: 1992
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37130 |
| Date | 11 September 1991 |
| Creators | Shanks, Carol A. |
| Contributors | Rohovec, John S. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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