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Hair Loss in Dogs


Alopecia in Dogs


Hair loss (alopecia) is a common disorder in dogs which causes the animal to have partial or complete hair loss. It can affect a dog's skin, its endocrine system, its lymphatic system, and its immune systems. Alopecia can affect dogs and cats of all ages, breed and gender, and is either gradual or acute.


If you would like to learn more how alopecia affects cats, please visit this page in the PetMD healthy library.


Symptoms and Types


Alopecia is extremely noticeable, and is characterized as a varied or a symmetrical hair loss. It may also be seen as bald circles, accompanied by crusting and inflammation around the area. Some dogs suffering from alopecia have scaling of the skin.




One of the most common causes of alopecia is mange, which caused by the mite Demodex. Hair loss can also occurs when there is a disruption in the growth of hair follicles, often from infection, trauma, an immune disease, or endocrine system abnormalities. If there are multiple missing patches of hair, it could be associated with an inflammation of the hair follicle. A more widespread area of hair loss, meanwhile, may indicate a more specific disease pattern.




The pattern and severity of alopecia is essential for a proper diagnosis and treatment plan.


  • Multiple areas of hair loss — This is often accompanied by the reddening of the skin and mild scaling. A fungus such as ringworm or bacterial infections are generally associated with this type of hair loss. Another common cause includes scleroderma, a skin condition that develops from scar tissue or as a result of a recent vaccination.
  • Symmetrical hair loss — There are several known causes for this, including excessive levels of steroids in the dog's body produced by the adrenal glands, low thyroid levels, increased levels of estrogen, low levels of female hormone secretion, and testosterone-related hair loss (occurring when the levels are lowered suddenly in the dog).
  • Patchy to generalized hair loss — Mange is one of the most familiar causes of this type of hair loss. Other causes include bacterial infections and ringworm. It is is accompanied with redness of the skin and inflammation.




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