Dog dandruff and excessive shedding are two issues that may not necessarily occur at the same time. While both can be frustrating for an owner, some issues may not need or benefit from treatment. For example, some breeds of dog are known to shed more. Therefore, potential owners who do not wish to deal with excessive shedding should opt to adopt dog breeds that are known to be low shedders. However, other causes of dandruff and unusual hair loss can benefit from the knowledge of a veterinarian.
In dogs, an allergic reaction is displayed through symptoms associated with the skin such as excessive shedding or hair loss. This loss of fur can occur because of contact allergies or due to the excessive itching associated with an allergic reaction. It may also occur due to allergic reactions of foods, vaccinations, medications or various parasites such as fleas or ticks.
Various autoimmune disorders, such as alopecia areata, can cause mild to severe hair loss. Some of these diseases may cause patchy hair loss or they may cause widespread shedding.
In some dogs, diabetes mellitus may cause thinning of the skin and small hair loss. This could mean that a dog sheds more than usual, even if he is a low-shedding breed.
Dermatomyositis is a skin condition that causes both hair loss and crusty, scaly skin or dandruff. It affects the face, ears and tail of an affected dog and is often aggravated by trauma or exposure to sunlight or other forms of UV light.
Skin infections can include yeast (malassezia) infections, ringworm and various bacterial infections. Skin infections, known as pyoderma or impetigo, can cause both hair loss and dandruff. They can be treated easily and the unusual hair loss and dandruff will dissipate.
Certain types of hereditary diseases may cause hair loss or excessive shedding. Though rare, black hair follicular alopecia is a condition in which the dark or black hair falls out. Black hair follicular alopecia may also cause scaling of the skin, or dandruff. Other hereditary diseases that may cause hair loss or unusual shedding include mutant alopecia, follicular dystrophy or pattern alopecia; which is the equivalent of pattern baldness.
Parasites, such as demodectic mites or cheyletiella mites, can cause hair loss and canine dandruff. Cheyletiella mites are known to cause unusual and excessive dandruff in affected dogs, though hair loss may only occur if there is a large mite population present in the skin.
Dogs who spend any time outdoors may be subject to solar dermatosis. Affected dogs will have a poor skin reaction to the sunlight, which can cause hair loss and scaling. This condition is particularly common on the unpigmented portions of skin or on the noses of certain breeds, such as the shetland sheepdog or the collie.