Is a Poison Ivy rash contagious?

What is in Poison Ivy that humans are allergic to?  How do you treat Poison Ivy? Are dogs & cats allergic to Poison Ivy? For free home activities sign-up at www.WhoSmarted.com See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.