All animals may potentially be affected, but the primary risk is to cattle. Poor doer, poor appetite, weight loss, diarrhea or constipation, increased drinking, increased urination, edema, death is possible.
Oaks are trees with leaves that turn brown but hang on through the winter.
In the southwestern U.S., Gambel's oak, shinnery oak, and post oak frequently cause poisonings. In our part of the country, red oak has produced problems. This discussion refers primarily to cattle, the species most often affected by oak toxicosis. It also seems that cattle less than 2 years of age succumb to oak toxicosis more than do older animals, however older animals are still at risk. Other species at risk include sheep and possibly deer.