There are regional differences in how we refer to the various plants. Around here regardless of having come in contact with poison oak or poison ivy, we just say "I got poison ivy". Identification of poison ivy can be very difficult. According to Dr. William Epstein (professor emiritus at University of California Berkeley) there are so many variations in the poison ivy plant and its characteristics nationwide that the best way to get positive identification is to consult a local expert. What is poison ivy in Virginia is not the same looking as what is in say Michigan. I have seen many variations in the leaf shape and structure just across a few states here in the Mid-Atlantic. Perhaps this is a case of misidentification?

The result is the same though for contact with either poison ivy or poison oak. Poison oak and poison ivy both have a secondary chemical, urushiol oil, which is what is toxic to us. It is generally believed that this secondary chemical is part of the plants defense mechanism against bugs and animals. Seems to work well against us - not so well against other animals.