Help! Black dog playing Frisbee?

My new little lab pup, Lilly, loves to play Frisbee. How do I get decent shots of a black dog running and jumping? Any help would be appreciated. I have been shooting on AV 4.5 ISO 800 and this is the best I've gotten.

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First, get away from mottled light, plus find a spot where the background is less distracting and further from the subject. Get lots of light on the dog, so can get shutter speed of at least 1/800sec. To get the dog the correct black, over-ride the auto exposure of your camera. For that, you have a number of options: 1. Since the dog is over-exposed, set one or more stop of negative exposure compensation. 2. Use the exposure lock button, *, to expose from a neutral-exposure target such as grass or even the back of your hand. 3. Expose from a grey card. 4. Use Manual mode, M, first to expose the over-all scene correctly - and only then add the dog. Use Spot focusing, on the dog, in AI Servo, rapid fire drive mode. It's hard work at first, but worth your while. You've a nice dog there.

Change your mode to TV rather than AV that you used in the picture or as meanderthal said use manual mode but wither way use AI servo and try spot focus. You're close. The light is harsh maybe try early in the morning or late in the day when the light is softer. If you're not shooting RAW switch to raw so you can adjust exposure as well and adjust the exposure in other parts of the frame more easily.

Thanks for the tips, I will try them and keep at it. I'd love to get the "perfect" shot of her in the air to give to my daughter as a print for Christmas.

I, too, have a black dog, and I find that some fill flash from my 430EX II helps to provide some detail in his fur. Aside from that, all of the comments above make sense for a black dog in rapid motion.