Often a dog's white coat will become dingy and yellow. While the yellow or dingy coat doesn't harm the dog, you might want the dog's coat to look whiter. To get white coats looking brighter, wash and apply cornstarch. You will have to shampoo your dog about once a week and apply cornstarch as needed. Special whitening shampoos for dogs can be applied to whiten fur and keep coats looking fresh.
Wet your dog's fur in the bathtub. The water should be only a little warmer than room temperature. Apply whitening shampoo to the dog's fur and work up a lather. Rinse off the shampoo.
Dry the dog completely with towels. You may need to wait a while until your dog's coat can completely air dry.
Pour cornstarch onto your hand. Pat the cornstarch through the dog's coat, covering every white area. Reapply cornstarch to your hands as needed.
Work the cornstarch through the coat until none of the starch is visible by patting and rubbing with your hands.
Wash the dog every week or so with whitening shampoo or as directed on the bottle.
Make sure your dog's fur is completely dry before applying the cornstarch. Use a nonslip bath mat in the tub so your dog doesn't slip. If your dog's ears get wet, dry them thoroughly with a soft towel to prevent infection. You can also use a dog brush to brush through the cornstarch.