Zoonotic transmission of Hepatitis E Virus from Hepatitis E Virus infected pigs (uncooked or undercooked pork) or cows (milk) to humans or non-human primates has previously been confirmed. Yes, the Hepatitis E Virus is excreted into milk that is produced by infected cows. Drink it unpasteurised and you're likely to get infected.
Now, researchers have studied stool, blood, tissues and milk of goats for Hepatitis E Virus infection investigation in Yunnan Province in China. Not surprisingly, a high prevalence of Hepatitis E Virus infection in goats was found. Analysis revealed that all Hepatitis E Virus isolates from those goats belong to genotype 4 and subtype 4h, and shared a high similarity (>99.6%) with Hepatitis E Virus isolated from humans, swine and cows in the same area.
Which means that Hepatitis E Virus is circulating in at least four different species and that poses a near certainty that the virus will mutate in the foreseeable future.
 Meng et al: Prevalence of antibodies to the HEV in pigs from countries where HEV is common or rare in the human population in Journal of Medical Virology – 1999
 Huang et al: Excretion of infectious hepatitis E virus into milk in cows imposes high risks of zoonosis in Hepatology – 2016
 Long et al: High prevalence of Hepatitis E virus infection in goats in Journal of Medical Virology – 2017