Can anyone tell me if walnut trees, the edible type are poisonous to horses?

http://forum.horsetopia.com/health-nutrition/51139-walnuts-harmful-horses.html

http://www.understanding-horse-nutrition.com/black-walnut-tree.html

http://en.wikipedia.org/wiki/List_of_plants_poisonous_to_equines

I know that the Black walnut is poisonous but can any one tell me if the English Walnut Tree is poisonous?

We have 1 acre of walnut trees, not the ones you eat, these trees are for their timber,We have run our Miniature horses on this land for 5 years,With thousands of Walnuts on the ground,Never seen them eat one,and certainly had NO problems. Regards Suffolklass

If you google English Walnut trees most sites say the same kind of thing.

This is an example:

Most members of the Walnut family (Juglandaceae) produce a chemical called "juglone" (5 hydroxy-alphanapthoquinone) which occurs naturally in all parts of these plants. Black walnut, pecan, hickory and others members of the family including Carya, Engelhardtia, Juglans, Platycarya and Pterocarya can produce juglone.

Black walnut and butternut produce the largest quantity of juglone and can cause toxic reactions with a number of other plant species that grow in their vicinity. Other juglone-producing species including English walnut, pecan, shellbark/shagbark/bitternut hickory, produce such small quantities of juglone that toxic reactions in other plants are rarely observed.

We have had horses eat the walnets that have fallen from our tree and until we refenced, they even stripped some of the bark - no ill effects. The tree is 100's of years old and the walnuts are enjoyed by all of us inlcuding the dogs and chickens.

Ditto Summer. We have dogs and horses who all love to eat walnuts. One horse even strips the tree so we have to keep her away or we don't get any. They're all still fit and well!!