Pistachio

Pistachio trees (Pistacia spp) are evergreen or deciduous resin-bearing shrubs and trees that belong to the Anacardiaceae plant family, which contains over 70 genera and 600 species. Of them, the most important to horses is P. atlantica, P. terebinthus, P. vera, P. khinjuk, and P. chinensis. P. vera is the only species of the genus used for commercial purposes.

Pistachio Tree Toxic Components

Pistacia spp. contain tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol, which are oxidizing toxins. If eaten, it causes hemolytic anemia and methemoglobinemia. The effect is similar to that seen by eating wilting red maple leaves and high doses of onions or garlic.