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Pediculosis 767

TREATMENT

VetBooks.ir Treatment Overview Diseases and Disorders
The goal is to try to promote hair regrowth if
this is the desire of the owner; it may protect
the dog from cold climate.
Acute and Chronic Treatment
Anecdotal evidence exists for the efficacy of
melatonin (3-6 mg/DOG PO q 8-12h for 2
months) to stimulate hair growth. Improvement,
if any, should occur within 2 to 3 months.

PROGNOSIS & OUTCOME
• Dogs affected by this genetically based
dermatosis are healthy otherwise.
• It is not known whether dogs initially
responding to melatonin will eventually
become refractory to this form of treatment.

PEARLS & CONSIDERATIONS
PATTERN ALOPECIA, CANINE Pattern alopecia (ventral type) in a 2-year-old neutered male Boston terrier.
Note loss of hair and lack of signs of inflammation on the ventral neck and thorax. (Copyright Dr. Manon Paradis.) Comments
The early-onset, pattern-linked alopecia and
The early onset, breed predisposition, and • Ruling out other differentials may involve breed predisposition make the diagnosis
absence of inflammation and pruritus are thyroid testing, adrenal function testing, and straightforward in many cases.
distinctive. dermatologic diagnostic tests such as skin
scraping based on lesion distribution and Technician Tips
Differential Diagnosis appearance. The main impact of this disorder is cosmetic
• Endocrinopathies (hypothyroidism, hyper- rather than medical.
adrenocorticism, hyperestrogenism) Advanced or Confirmatory Testing
• Follicular dysplasias Skin biopsies: changes are characterized by SUGGESTED READING
• Alopecia areata miniaturization of anagen hair follicles. Biopsies Paradis M: Canine pattern alopecia. In Mecklenburg
• Infectious process (pyoderma, demodi- are rarely performed because biopsy at affected L, et al, editors: Hair loss disorders in domestic
cosis, dermatophytosis) in some clinical sites often requires general anesthesia, biopsy animals, Ames, IA, 2009, Wiley-Blackwell, p 164.
presentations healing may lead to permanent visible scarring, AUTHOR & EDITOR: Manon Paradis, DMV, MVSc,
and histopathologic changes can be subtle and
Initial Database wrongly suggest endocrinopathies. DACVD
• History and physical exam findings are
generally sufficient.

Pediculosis

BASIC INFORMATION GEOGRAPHY AND SEASONALITY HISTORY, CHIEF COMPLAINT
• Possibly more common in winter • Pruritus may be severe and affect
Definition • Rare in many parts of the world (espe- several animals. Often, no history of skin
Louse infestation cially areas where flea control is routinely disease
practiced) but common in other regions • Lice or nits (small, white ova) are often
Epidemiology (e.g., canine sucking lice in Western noticed by owners or groomers.
SPECIES, AGE, SEX Canada) • Weakness (puppies with sucking lice)
Affects dogs and cats of any age, with young
patients predisposed ASSOCIATED DISORDERS PHYSICAL EXAM FINDINGS
• Anemia, debilitation (puppies) • Unless parasites are seen, exam findings are
RISK FACTORS • See Physical Exam Findings nonspecific. Lice are smaller than fleas but
Dogs: frequent contact with other dogs (groom- Clinical Presentation visible to the naked eye. They accumulate
ing, day care), neglect, overcrowding around ears and body openings. Detection
DISEASE FORMS/SUBTYPES is difficult if numbers are low. Nits are
CONTAGION AND ZOONOSIS Chewing versus sucking lice: differentiate often seen attached to hair. In some cases,
• Contagious to same species only; not zoonotic by microscopy; broad head on chewing lice; excoriations, scaling, matted hair, alopecia,
• Transmitted by direct contact, grooming slender, tapered head on sucking lice and other findings:
instruments, premises

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