(St. Paul, MN) -- The D-N-R is confirming three rare equine diseases in three different Minnesota counties. Two of the diseases, eastern equine encephalitis in Otter Tail County and West Nile virus in Swift County, are spread by mosquitoes and pose a risk to horses and people. The third disease, equine infectious anemia, found in Pine County, is not known to affect people. But it does require infected horses to be euthanized or quarantined for life because there is no treatment or vaccine.