I read the one day. For your dog's nails not to grown that long cut their nails regularly only a little piece. That will give the "bloodsupply / kwik" time to grow back / shorter in the nail. Just be carefull not to cut to deeply. It will cause bleeding in the nail.
How do you cut your dog's nails that are black?
If you look at the dark nail head-on, you will see a small dark circle. Once you see that, you should stop. If you cut a nail too short and it begins to bleed, apply pressure to the tip of the nail to stop the bleeding, or dip the nail in the cornstarch or styptic powder.
Rinse your dogs regurarly aswell. To avoid an itchy skin. Please use their special shampoo when washing them proporly. . When changing their bedding, we use salt to wash our pets blankets and hang them in direct sun. We sprinkle flea powder into and onto their freshly beddings to avoid fleas.
I hope it helps