If you're taking pictures on a sunny day, you may want to try using a special film. Film which is labeled ASA 200 works well in sunlight. For example, a black horse might look best if she is standing in front of a white or yellow fence or shed. If your pet is light-colored, see if you can find something dark as a background. For example, if you have a white dog, she might look good sitting in front of a dark green bush.
Some pets know how to sit still on command.
Panning means that you're going to move your camera the same way your subject is moving. Let's say your horse is running down the length of the pasture. You point your camera at him and follow him, clicking the button as you go. Put it in a special mailer envelope or in an envelope with a little thin cardboard to protect it. Put the same amount of postage on BOTH envelopes.