Non-human primates can, too, die before exhibiting obvious symptoms. Recorded symptoms include diarrhea (sometimes bloody), various sickness behavior (low energy, low appetite, depression), significant weight loss, dehydration, and hypothermia. Occasionally there are rashes, erythema nodosum, and arthritis just like in human "Izumi fever". The ypmA gene may be responsible.

Birds generally die without warning, or after only exhibiting lethargy, diarrhea, and