Definition of the Disorder
Alopecia is defined as any deficiency of the normal hair coat. It does not necessarily refer only to hair “loss.” Alopecia includes a hair deficiency due to either to failure of the hair to grow or loss of all or part of the hair shaft after growth has occurred.
How Alopecia Affects Dogs
Alopecia is one of the more common complaints of dog owners. How alopecia affects a dog depends upon the underlying cause of the condition. Hair loss (or failure to grow) can occur anywhere on the body of a dog of any age, breed or gender, including on the face, around the eyes, on the back, near the base of the tail or on the flank. The hair abnormality may occur on its own without any apparent cause or other clinical signs. Alternatively, the absence of hair may be accompanied by scratching, redness, pustules or other skin changes. Alopecia can appear symmetrically in discrete but well distributed patches, or it can have no pattern at all.
Causes of Alopecia in Dogs
Alopecia can result from a number of different biological processes, again depending on the underlying cause of the condition. The hair may never grow in affected areas, or it may not re-grow after first growing and then falling out. Moreover, there is a significant difference between grown hair fibers falling out, hair tips breaking off with stumps of fibers remaining and a complete absence or loss of the hair root from the hair follicle. Potential causes of these various processes include endocrine disorders, hormonal imbalances, parasites, inflammation, bacterial or fungal infection, genetic disorders, congenital disorders, trauma-induced hair breakage, allergic reactions and other immune-mediated conditions.
Prevention of Alopecia in Dogs
Given that alopecia is not a “disease” but rather is the result of some other disorder, there is no single way to “prevent” the condition from occurring. Prevention or management will depend upon the underlying cause of the hair deficiency.