It can be common to see owners of dogs, cats, and other lap sized animals with their pets. These images often depict a close connection between the owner and the animal. It can be tricky though to get the same connection between the owner of a larger animal, lets say a horse, and its owner.
If you can show interaction between the animal and its owner (or model) you are going to get a much more compelling image rather than just having a person standing next to the animal. You will want a well exposed image of both the face of the animal and of its owner, which can be tricky with significant tonal differences. In the image above, the horse was dark brown with of course, dark brown eyes. The model has fairly light skin and features. Careful attention to light and shadow on both, and in many cases, a fill flash can work wonders in bringing out details.
The first image may look ok, but could easily be anyone standing near a horse and with a telephoto lens, the distance could be easily compressed. The model could have been photographed riding the hose, but again that may only show a rider and a horse. The second image shows the model actually in contact with her horse, and in fact the horse brushing against her face. The second image is a little more compelling showing the connection between the two in the image.
You often have to be ready for almost anything. So keeping your camera and subject framed tightly can be a key to some good images. A relatively shallow depth of field also helps keep the viewers eye from distracting background images. For sharp images you will want to keep your shutter speed relatively high around 1/200 of a second to avoid out of focus images. Obviously for the sake of the animal and those around it you will not want to force anything, but if the animal is not in the mood to 'model' a small container of food can work wonders. If the animal has not worked with the 'model' in the past, it may take a little time for the two to get to 'know' each other, so allowing for the extra time is often a great idea. Some 'horse-play' may end up with some great images.
It's worth mentioning that this post is intended for domestic animals, and posing around 'Wild' animals can be particularly dangerous and unpredictable. Some commercial facilities that feature posing with wild animals may actually drug the animal to make it more docile which clearly is cruel to the animal.
Try 'making the connection' on your next animal/human photoshoot and you may be amazed at the results.