Adobe Photoshop gives photo editors the power to change the colour of dog fur to virtually any hue. Some colours are more suitable than others for maintaining the natural look of the fur. Changing a dog's fur to white poses particular difficulties even though it is a colour that occurs naturally in animal fur. The challenge with white is that the colour must be removed and the hair lightened while still preserving the shadows and texture of the hair.
Open the photo you wish to edit in Photoshop.
Click on the "Adjustment Layers" icon, the half-white, half-black circle at the bottom of the "Layers" window. Select "Hue/Saturation" from the menu that appears. This will bring up a dialogue window with several settings.
Move the bar labelled "Saturation" all the way to the left, bringing the saturation to zero. You should see all of the colour leave the image. Adjust the lightness bar upward until the dog's fur looks white, but not so far that your lose all detail from the fur.
Use the shortcut "Ctrl+Backspace" (for Windows) or "Command+Delete" (for Mac) to change the colour on the adjustment layer mask from white to black. All of the colour should return to the image. Painting on the mask controls which part of the original picture is affected by the adjustment layer that you just created.
Select the brush tool from the toolbar; at the top of the screen the brush options should appear. Start with a large brush at full opacity and paint the general area of the dog's fur, leaving for now the edges and the face. Shrink the brush and lower the opacity with the brush options to paint more detailed areas at the edge of the dog's fur and its face.
Switch to the eraser tool to correct any areas that you turned white that aren't part of the dog's fur. You can use the blur tool to blend any area where brushstrokes look too obvious.
Click on the adjustment layer to bring up the layer settings again. Tweak these settings until the dog's hair looks white but also maintains the maximum amount of texture.
Changing the blending mode of the adjustment layer with the box on the layers menu to soft light or dodge mode may give you a more subtle adjustment; otherwise you can leave it at normal.
Don't save over your original, because you may want to go back for comparison or to try again.