brush should I use on my dog?"
If you gently tug a sample tuft of your dog's fur between your thumb and index finger and examine the fur strands in your hand, what do they look like? If they are all the same length and are short and straight in appearance, then your dog has what's called a short haired or flat coat, meaning it has only a top coat which can be kept free of loose, shedding hair with a rubber brush such as a "zoom groom" commonly found in pet stores. If you also notice fine, whispy or crinkley strands, then your dog also has an undercoat that can be managed with a specialized undercoat brush such as a Furminator. Before you buy a brush for your dog, it's important to identify what kind of coat your dog has.
Dogs like pitbulls and labs have a short outer coat that is best managed with a rubber brush. My favorite is called a zoom groom, and it works by basically pulling out loose fur as it is rubbed over your dog's coat.
The undercoat is comprised of silky strands that are designed to keep your dog warm. A top coat typically covers the undercoat, so the undercoat can go unnoticed and ungroomed in some breeds with short fur like labs and golden retrievers. Zoom groom brushes succeed in removing *some* of the loose undercoat, but it is not designed to penetrate the top coat to reach the undercoat so if your dog also has an undercoat, shedding may continue. Traditionally, groomers "card" these types of dogs by modifying a grooming blade into a specialized undercoat brush. We do this by removing the moving part (the sharp part) of a #40 blade and raking the teeth of the modified blade over the coat to penetrate the top coat and remove undercoat. The problem is, unless you are trained to use the blade properly, you can easily irritate your pet's skin as well as cause great strain to your hand. A brush called the furminator is essentially the same thing as a carding blade but it's larger (to cover more hair) and it has a handle. You still need to keep a close eye on your pet's skin as you brush though. If it becomes red, stop immediately. Also, this brush is not designed to work only on loose hair. If you continue to brush an area, you can literally remove all the undercoat and end up with a balled spot (and irritated skin). But if you are careful to watch the skin and coat as you brush, this tool will prove to be invaluable for eliminating shedding.
Coat--Slicker Brush & Comb
If you have a shihtzu, maltese, lahsa apso, yorkshire terrier, or any dog with long flowing hair that is similar to straight, human hair, all you need is a slicker brush and a comb to remove knots. The comb should glide through the fur without getting stuck.
Coats--Comb & Slicker Brush
Dogs like poodles and bichons look their best when their fur is "fluffed" with a comb regularly. Slicker brushes are useful for removing knots, but like with drop coated breeds, a comb should glide through the coat without resistance.
Coat--Slicker Brush or Pin Brush
Most terriers and dogs with wiry hair benefit most from a slicker brush. Most dogs don't mind the slicker brush, but if your pet doesn't like the slicker brush or seems to flinch as you use it, your dog may be trying to tell you it has sensitive skin. If this happens, try switching to a pin brush instead as it is not capable of scratching the skin.