Encephalopathy of mink: II. Experimental and natural transmission

Mink injected with brain suspensions from natural cases of mink encephalopathy developed the disease syndrome 5 months after intramuscular inoculation. Following alimentary infection with brain material a lengthened incubation period of about 8 months was observed. Seitz filtration indicates that the agent is smaller than 500 mµ. In unfiltered brain suspension it is resistant to boiling (15 minutes), to 0.3% formalin (12 hours at 37 C), and to diethyl ether. These properties, along with the clinical and histological features of this syndrome, have some similarity to those of scrapie of sheep. Although encephalopathy is poorly contagious among mink, field evidence suggests that on occasion the disease can be acquired by cannibalistic ingestion of flesh from diseased mink.