A good description of how to understand the metaphor of an animal in a dream is in this radio show. To listen to it, you can click here.
Animals are really good metaphors for dreams because every animal has certain distinct qualities. You can think about the qualities of an animal and think about where in your life there are the negatives qualities of the animal showing up but also think about where inside your self do you have the positive qualities of the animal. You can find ways to show the positive qualities and your life will keep getting better and better.
A good example is a German Shepard dog. The positive qualities of the German Shepard are loyalty and friendliness. The negatives are fierceness and aggression. If there has been negatives in our life like abuse or aggression then we might have a dog in a dream showing aggression. This just means there is some work to do to let go of the old memory of that experience. The solution is the positive. To be friendly and loyal will help solve the aggression issues.
In this way as the dreamer shows more and more friendliness and attracts more friendly people into their lives then the dogs in the dreams might be more and more friendly and positive too.
Any animal dream works with this same principle. Understand the negative; notice where in life it might be showing up; and use the positive quality to make things better.
If you try out a few things and want to share examples, please leave a comment. I’d be happy to read it and see how it goes for you.