Laboratory tests
Laboratory tests are necessary to demonstrate the presence of the virus or its antibodies and identify the viral strain. Possible tests include polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), haemagglutination (HA) tests, electron microscopy or immunohistochemistry (OIE 2019). In the UK and many other countries, PCR testing is the laboratory test that is available to the veterinary practitioner.
PCR testing
PCR testing is available at several laboratories in UK although the samples may be sent abroad to be tested. Samples of liver, faeces, intestinal contents, blood or an oral or rectal swab may be submitted for PCR testing against RHDV1 and RHDV2 but liver samples are the most reliable. This is the organ with the highest quantity of viral RNA. False negative results are more likely from other samples. False negative results are also possible, but unusual, from liver tissue collected from rabbits that have died from RHD (Harcourt-Brown et al. 2020, in press).
Qualitative immunochromatographic assay
A test kit using a qualitative immunochromatographic assay (Certest RHDV+RHDVb) is available from a company in Spain. It gives immediate results for the presence or absence of RHDV1 or RHDV2 virions in tissue samples or abdominal exudate collected during post-mortem examination. There is a possibility that this test may be discontinued at the end of 2020.