The first promising blood test for mad cow (vCJD) was developed in 2016. Prior to that, "The only current method to diagnose vCJD is to perform a biopsy or a p

The first promising blood test for mad cow (vCJD) was developed in 2016. Prior to that, "The only current method to diagnose vCJD is to perform a biopsy or a postmortem analysis of brain tissue." (NIH 2017). https://www.nih.gov/news-events/nih-research-matters/new-method-accurately-detects-prions-blood https://www.nih.gov/news-events/nih-research-matters/new-met... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5538786/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5538786/ Scientists have since developed a promising method that relies on analyzing the retina. https://www.nih.gov/news-events/news-releases/scientists-identify-locations-early-prion-protein-deposition-retina https://www.nih.gov/news-events/news-releases/scientists-ide...