Aside from skin whitening products, what makes a man turn white? One reason would be a sudden shock triggering fear, which makes the blood flow temporarily stop in its tracks, giving him a pale look. What makes a dog turn pale? That would be hard to tell because of all the hair surrounding its body, but you could see the changes in the pink fleshy skin around its mouth and eyeballs - the cause of that would most likely be Canine Anemia. This condition is characterized by a loss of red blood cells in its body. Red blood cells act as "delivery boys" carrying important "packages" for the different "departments" inside humans, as well as in dogs.
The package of importance is oxygen, which is needed by the other tissues in the body to carry out their functions. Each "group" needs a certain amount of oxygen delivered at a certain amount at a specific time depending on the needs of the body. It's a fascinating process (for geeks), but I won't go into the details and explain everything nor use scientific terms as to not bore you. The busy system needs to kept constant - if lots of the "delivery boys" don't report for work (because they're dead), there will be consequences. The first symptom or "attack" because of the depletion of red blood cells would be pallor around the eyes and mouth of the dog, as I've said earlier.
There are three causes of anemia - the first way is the actual destruction of the "beloved delivery boys" - this may be caused by parasite infections in the blood cell, blowing it up, and spreading to the others nearby. Poisons may also work in the same way as the parasites do, but usually reeking havoc at a faster pace. Another cause could be bacterial toxins, and as well as immune reactions. The 2nd cause of Anemia is a more "physical process" - an example would be it getting stabbed by a sharp object, such as a knife, and blood spilling out. That will lead to a severe loss of red blood cells, especially if left untreated.
Ulcers, whip worms, and tape worms can also serve as a plausible "starter" for the 2nd type. The last cause of Anemia would be an abnormal production of red blood cells in the bone marrow. What causes the irregular production? Tumors are a known stimulant, and so are kidney ailments and other severe infections. Not giving it a balanced and complete diet also generates Anemia. Symptoms of the dog disease includes laziness, weakness, faster pace of breathing, and other unusual canine behavior. Don't break a sweat, it's nothing to worry about as long as you bring it to a veterinarian for a check-up and treatment.
From there the vet will give the canine disease treatment program according to the main root of the ailment. He may also suggest to give it plenty of rest, as well as change your pets food diet, and offer vitamin and other nutrient supplements - if your dog has developed the disorder, rest assured that it'll be better in no time.