Alopecia: An Overview
Alopecia is defined as a loss of hair, partial or complete, in areas where it normally grows. Shedding is a normal process in dogs where dead hair is lost so new growth can occur. Excessive shedding can occur when the seasons change or when a dog is stressed but this shedding does not normally result in bald patches. Alopecia can occur in any breed of dog and has numerous causes. Any abnormal hair loss noticed in your dog should be mentioned to your veterinarian.
Causes of Alopecia
There are numerous causes for alopecia. The loss of hair normally results from an underlying cause which can range from basic allergies to metabolic disorders to inherited diseases. The causes are divided into two main categories Hereditary and Acquired. Hereditary alopecia is genetic and is passed from parents to offspring. Some hereditary causes are black hair follicle dysplasia and color dilution alopecia. In certain breeds, such as the Chinese Crested, this alopecia trait has been selected for. Acquired alopecia is separated into two divisions: inflammatory and non-inflammatory. The most common causes of alopecia are normally found in the acquired inflammatory category. Some examples include food allergies, flea bite allergies, folliculitis, and sarcoptic mange. Acquired non-inflammatory types are also common and include acral lick dermatitis, calluses, and gestational hair loss. There are many other causes of alopecia each which can affect your dog; with your veterinarian’s help a definitive cause will be able to be identified.
Symptoms of Alopecia
Hair loss is the clinical sign of alopecia. The hair loss can be very noticeable or very inconspicuous. It can be a single small patch, multiple small patches, symmetric (the same on both sides), or cover the entire body. There are many ways which alopecia can present and this can be helpful in determining the cause.
Due to the vast number of causes associated with alopecia a diagnosis may not be made quickly. A complete and careful history is needed to start the process. Things such as breed predisposition, the duration and progression of the alopecia, the presence or absence of itching, and the distribution of the hair loss are just a few of the questions which may be asked when the dog’s history is being taken. A physical examination of the dog will also be necessary. A skin scraping may be taken to allow the veterinarian to see which part of the hair follicle is being affected as well as if there are any mites or bacteria present on the skin. In addition to the skin test, blood and urine tests may be done to rule out or confirm certain metabolic disorders.
The treatment prescribed will depend on what is causing the alopecia. In most cases treating the underlying cause will stop hair loss and allow for new growth to occur. For cases where a diagnosis has not yet been made, medicated shampoos and vitamin supplements may be used to help facilitate new hair growth. Once the cause has been determined the prognosis that the dog?s hair will return is good, although it may take months for the coat to completely return to normal.
Care for dogs with Alopecia
When caring for dogs with alopecia it is important to remember that they do not have as much protection from the elements as dogs with full hair coats do. Your dog may need to wear a coat or sweater during cold months to keep them warm. During summer months you will also need to make sure your dog does not get sunburned. Owners should also be aware that when a dog has alopecia their skin is more susceptible to bacterial and fungal infections. If you notice your dogs condition getting worse contact your veterinarian right away.
The AKC Canine Health Foundation and Alopecia
Six grants to study alopecia have been funded by CHF. The grants look to increase the current knowledge about the causes of alopecia along with developing new treatments to promote hair growth.
Treatment and Prognosis of Alopecia in Dogs
Alopecia is usually a sign of an underlying disorder, which must be diagnosed accurately in order for effective treatment to begin. If the hair loss is accompanied by scratching, pustules, hot spots or other lesions, it may be appropriate to apply topical medications to manage and hopefully alleviate the discomfort caused by these conditions even before the actual cause of the alopecia is determined. The veterinarian may prescribe ointments, creams, lotions, shampoos or other soothing treatments to calm any inflammation associated with alopecia. She also may recommend oral or topical antibiotics, antihistamines and/or anti-inflammatories as part of an initial treatment regimen.
There are a number of topical medications to treat alopecia caused by external parasites. Flea and tick control, and shampoos or other products that kill mites, lice or fungi, are generally quite effective in resolving parasitic alopecia, although it can take weeks to months for the hair to grow back completely.
Alopecia Due to Endocrine Disorders or Hormonal Imbalance
Alopecia caused by endocrine or hormonal abnormalities is managed by treating the underlying disorders. For example, alopecia associated with hyperthyroidism or pituitary dwarfism can be treated with lifelong hormone replacement medication. Spaying and neutering can be successful treatments for hair loss caused by certain other hormonal imbalances, or even stress.
There are a number of treatment options for alopecia caused by immune-mediated reactions. These include medicated shampoos, topical and oral anti-inflammatories and antihistamines, and corticosteroid therapy. Of course, if a veterinarian can identify the cause of the reaction and remove the allergen from the dog’s environment, allergic alopecia should resolve in short order.
Essential fatty-acids, Vitamin D, and oral melatonin supplementation have been found to be safe and variably effective in stimulating hair regrowth and improving overall coat condition in dogs.
The prognosis for recovery from alopecia is good in most cases, if the underlying cause of hair loss is identified and treated. If the skin has suffered extensive scarring, hair regrowth will be more limited.