Hemorrhagic Diseases of White-tailed Deer (continued)

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Sampling

If a hemorrhagic disease in a WTD is suspected, a confirmed diagnosis requires identification of the virus from sick or freshly dead deer with clinical signs or lesions.  The following samples are to be taken for laboratory diagnosis:

1. Tissues: Spleen, liver, kidney, lung, lymph nodes and heart. Fresh/frozen for virus isolation, taken aseptically and a second set fixed in formalin (10%) for histological examination.
   Samples should be sent on ice packs if the shipping time is less than 48 hours, or frozen if shipping will take longer than 48 hours.
2. Blood samples: Whole blood: 15-20 mL of heparinized blood. Whole blood is the sample of choice for BTV and EHDV diagnosis. This sample should be sent refrigerated at 4ºC.
3. Serum: 10 mL for serological diagnosis.
   Upon receipt of samples from animals suspected of having a BTV or EHDV infection, laboratory procedures are performed to identify the agent. Virus can be isolated from the blood or tissues of an infected animal if this material is put into a suitable host system where the virus can replicate.

Suitable host systems are cultured animal cells and embryonated chicken eggs. The most sensitive in vivo host system identified for BTV is 10 day old embryonated chicken eggs (ECE). After the virus has been suitably amplified in ECE, the virus is transferred to another host system (BHK-21 cell culture). Further amplification and viral identification is achieved by growing the virus in BHK-21 cells and detected by the immunoperoxidase assay.