When I dream of an animal or come upon a particular animal repeatedly, I often look up the Native American meanings behind it.  It can be called "animal medicine" or "animal totem".  The idea is that animals have lessons to teach us and can help act as guides just by the way they are "being" in the world.  I recently created a custom journal with a turtle on it.  The recipient wants to use the journal to record his dreams in and told me that the turtle is important to him.  It made me curious as to what turtle medicine is all about.  Here is a little bit that I found:

Turtle symbolizes both new beginnings and endings. It is through the ending of something that allows space for something new to arise. This ending may be of an outer circumstance or a change or shift that occurs within ourselves.There may be a sense of loss or even grief over what has passed and yet it is through the energy of Turtle who is very long lived and thus very wise, that we can come to understand why something did need to leave our lives. Turtle can help lead us to that space where we can finally move on, to let go of what has been, celebrate it for the gifts it gave us and finally to turn and head for a new shore. 

You can find this information and more about turtle medicine here.