Gary,

Just finished reading the link you have sent me...I do not agree with some points: origins and comments about the temperament.

we believe the Dogo as well as the Alano have been around for a very long time...as you could read in that brief article (if you allow me I will soon share a lot of information, that resulted from many years of research and field work).

about the temperaments...it is NOT an aggressive breed towards other dogs!!! They are required to work in groups of many dogs! Will they attack strange dogs that invade their property? Yes! 

They extremely docile with the human family, very rarely you will find a dominant dog (over the family).

and yes...they will give their life to defend any family member or the property...but only if REALLY required!  although they will prey on big game since thy start walking they will not bite an human easily! It will have to be a real threat to their loved ones!