Is ivy related to poison ivy?

Poison ivy [Toxicodendron radicans] actually is an allergen which becomes the irritant. The irritation/allergy is caused in 80% of humans is all due to presence of persistent urushiol resin. Urushiol is not an oil as some might think. Urushiol is considered poisonous. The reactions that it may cause in humans may or may not existent among animal populations. A pet dog may go outside, and come into direct contact with the oil, and have/ have no reaction. The dog's owner well may have a similar reaction when they touch the dogs previously exposed body parts.