Hair loss in non-primates - A syrian hamster has back alopecia

Alopecia: Possible Causes and Treatments, Particularly in Captive Nonhuman Primates

Link:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2703143/

 Here we consider 3 scenarios representing what might be the more common causes of hair loss in nonhuman primates and possible treatments.

Scenario 1.

If increased scratching is observed along with reddened skin, and biopsies have ruled out bacterial, fungal, or parasitic infections, then the most likely diagnosis is atopic dermatitis. If the source of the allergen cannot be identified and removed, then several treatment options are available depending on the research protocol. For nonhuman primates, treatment with oral steroids or cyclosporine should be considered. We successfully treated 1 aged female monkey with pronounced total-body hair loss, inflamed skin, and pruritis by administering dexamethasone orally for a period of several months, during the latter part of which the dosage was gradually reduced. Treatment was effective in restoring full body hair, and her coat has been maintained for well more than 1 year after treatment.

Scenario 2.

If the hair loss is self-induced (by hair pulling) and skin biopsies have ruled out inflammation and bacterial, fungal, and parasitic infections, then a tentative diagnosis is psychogenic or stress-induced hair loss. If the stressor cannot be identified and removed (possible sources include experimental procedures, husbandry practices, and other animals, among others), then 2 strategies might be useful. The first is an enrichment strategy in which the environment is modified to provide the animal with greater stimulation. Such changes might include pair housing. The second is a pharmacotherapeutic strategy in which the animal is treated for anxiety by using anxiolytic drugs such as diazepam. However, no systematic studies show that either of these strategies is completely effective in eliminating hair-pulling behavior. Moreover, any proposed treatments for alopecia must be compatible with the research protocol under which the animal is being studied.

Scenario 3.

If behavioral correlates of the hair loss are not apparent and skin biopsies reveal no evidence of skin inflammation or the presence of bacterial, fungal, or parasitic infections or alterations in hair follicle biology, then other factors have to be considered in the diagnosis. Three such factors include seasonal variation, reproduction, and age. Seasonal or pregnancy related-hair loss should resolve within 4 to 8 mo without treatment. If none of these factors is related to the hair loss or if the hair loss does not resolve, then hormonal imbalances and nutritional deficits should be ruled out. If the hair loss appears to be a natural consequence of aging, no treatment is currently available to ameliorate this condition in nonhuman primates.

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Conclusions

A variety of factors are known to produce hair loss in mammals and, more specifically nonhuman primates. Some of these factors are rare, accounting for only a small percentage of monkeys that show alopecia; others are probably much more common. In general, little is known about the prevalence of different types of hair loss in captive nonhuman primates, in part because of a tendency to view hair loss in this mammalian order as a unitary phenomenon related to stress. Identifying the causes of hair loss in individual primates depends on an assessment approach involving health exams, skin biopsies, blood screening, and behavioral observations. Knowing the cause is crucial to establishing effective treatment regimens. However, hair loss also can result from several causative factors working in concert. Furthermore, much remains unknown about treatment. Whereas some forms of alopecia can be treated (for example, hair loss associated with hypothyroidism), well established treatments are not available for other forms (for example, hair loss associated with hair pulling). In fact, simply monitoring the animal may be the best approach when underlying medical causes are ruled out and other clinical signs such as dermatitis or pruritus are absent. Finally, some forms of hair loss cannot be remediated (for example, mutations of the hairless gene, hair loss in some animals as a result of old age), and therefore alopecia most likely will never completely be eliminated from captive nonhuman primate populations. These problems underscore the need for future research on the causes of hair loss in nonhuman primates, not only to benefit their condition but also to develop new biomedical models to advance our understanding of alopecia in humans.