The University of California-Davis School of Veterinary Medicine reports that pistachio shell impaction of the small intestine, colon or abomasum resulted in intestinal rupture or ulceration and secondary peritonitis in multiple dry cows and first calf heifers on three dairies.

Dairies were purchasing pistachio hulls which apparently contained some indigestible, cracked, hard shells. The shells probably deposited in the intestine and abomasum occasionally damaging the mucosa by their sharp edges and in some cows they accumulated on one location causing bowel distension and rupture.

Read more news from the California Animal Health and Food Safety Laboratory System November 2012 newsletter here