Page 1500 - Clinical Small Animal Internal Medicine

1438 Section 12 Skin and Ear Diseases

alopecia is patchy throughout the coat, an inflammatory Table 163.3 Treatment options for select inflammation‐induced
VetBooks.ir cause is likely, whereas if the alopecia is diffuse and sym- Disease Treatment options
alopecic conditions
metric, a noninflammatory cause is more likely.

Diagnosis Sebaceous adenitis Vitamin A, synthetic retinoids,
ciclosporin, glucocorticoids
Vasculitis Tetracyclines/niacinamide, pentoxifylline,
Minimum Dermatology Database glucocorticoids
A minimum dermatology database consisting of skin Alopecia areata/ Glucocorticoids, ciclosporin
scrapings, fungal culture, and surface cytology should be pseudopelade
performed on all cases of alopecia. If infections are sus-
pected by clinical presentation (patchy alopecia) or laboratory parameters are within normal limits, endo-
detected by the dermatology database, then treatment crine testing may still be indicated.
should be pursued and alopecia reassessed before fur-
ther diagnostics are performed.
Additional Diagnostic Tests
If an older dog or cat first develops alopecia, screening
Trichogram for neoplasia becomes very important. Diagnostics in
Trichogram involves the plucking of hairs and exami- this case may include basic bloodwork, urinalysis, histo-
nation under the microscope. The tips of the hairs can pathology, and imaging.
be examined to determine if the alopecia is traumati-
cally induced (see above). The shafts of the hairs can Therapy
be examined to look for abnormal clumping of mela-
nin and distortion of the hair shaft, suggestive of color
dilution alopecia. This method is not useful for black Treatment depends on the cause of the alopecia.
hair follicular dysplasia, as the hair is too pigmented Table 163.3 lists treatment options for some of the
to allow for this observation. The bulbs of the hairs inflammation‐induced causes of alopecia.
can be examined for evidence of a preponderance of For many of the noninflammatory causes of alopecia
telogen hairs, which might suggest telogen defluxion associated with hair cycle arrest (alopecia X, patterned
when coupled with ease of epilation and supportive alopecia, cyclic flank alopecia, and postclipping alope-
history. cia), melatonin therapy may result in hair regrowth. The
recommended dosage is 3 mg q12h for small dogs and
6–12 mg q12h for larger dogs. Side‐effects are minimal,
Histopathology with the most common one being sedation. It is possible
that melatonin causes insulin resistance so it should be
Histopathology will help rule out many of the inflamma- used with caution in diabetic animals. Recently, medroxy-
tory causes of alopecia (e.g., folliculitis, sebaceous adeni- progesterone acetate injections were shown to be mar-
tis, vasculitis, alopecia areata, pseudopelade, neoplasia, ginally effective for treating some Pomeranian dogs with
or paraneoplastic dermatitis) but, as stated before, it sel- alopecia X.
dom allows differentiation of endocrine diseases from
other noninflammatory causes of alopecia such as alope-
cia X or patterned alopecias. It is helpful to first treat any Prognosis
infections that are identified prior to performing a biopsy
as inflammation associated with the infection could Alopecia in itself is seldom a life‐threatening condition
mask other causes of alopecia. although, in some instances, it may be a cutaneous
marker for a systemic disease that could carry a guarded
to grave prognosis. Most alopecia caused by pruritus or
Endocrine Testing
inflammation can be managed or treated once the under-
If noninflammatory alopecia is first occurring in a lying cause is identified. If follicular destruction occurs
middle‐aged dog, further investigation into a possible secondary to severe inflammation or ischemia, alopecia
endocrinopathy is warranted. This may include basic could be permanent. In addition, immune‐mediated
bloodwork and urinalysis to screen for abnormalities conditions such as alopecia areata and pseudopelade
consistent with an endocrinopathy. However, even if all may fail to respond to treatment.