Yes there are many diseases that horses can be born with or get throughout their life. Some can be life threatening and others the horse may live with peacefully not do much harm
lung cancer
pathogens
diseaes
di-sease 2
it has nothing to do with heart diseas
white disease, or smallpox
there was rats,,diseaes,,lice and other inhuman conditions
Roosevelt suffered from polio and died of a cerebral hemorrhage
Yes Parkinsons disease he was diagnosed with this in 1994
because if you do not have red blood cells you can not survive because red blood cellsprotect you from diseaes
Count Orlock initiated a plague in the city of Bremen due to his feeding. It wasn't explained what it was exactly however.
Many saints died of diseaes that were not curable at the time. St. Therese of Lisieux, St. Bernadette are just two examples.