October 4th, each year, people bring their pets to church to participate in "the Blessing of Pets". This custom is "in remembrance of St. Francis of Assisi’s love for all creatures". Source: www.americancatholic.org/Features/francis/blessing.asp
There's also an article from same page called "Will I See My Little Doggy in Heaven?" www.americancatholic.org/Messenger/Jul2003/Feature2.asp The writer lists 10 reasons (refers to Holy Scripture) why The Lord has a plan of salvation for our pets as well.
I thought this was interesting and hopefully gives people some comfort and hope.