Some other plants have two or three similar-looking leaves. Such other plants may have spines on the leaf tips (holly or Mahonia) or thorns on the stems (blackberry). However, it is better to avoid plants that resemble poison ivy. If you see a plant that has all the characteristics, but have regular, uniformly shaped leaves, or sharp tips on the edges, it's not likely to be poison ivy. Poison ivy has tips that are more randomly spaced and somewhat curved between the tips along the edges. Toxic plants are not poisonous to all creatures. Deer and other grazing animals may happily eat poison ivy.

TL;DR in Vietnamese:
Tránh nhầm lẫn cây sồi độc và thường xuân độc với những cây khác. Đừng mất cảnh giác với những loài cây chưa xác định cho dù bạn trông thấy các loài động vật khác ăn được chúng.