Page 1518 - Clinical Small Animal Internal Medicine

1456 Section 12 Skin and Ear Diseases

Feline Scabies sulfur dips for 4–8 weeks are beneficial. Treatment should
VetBooks.ir Etiology/Pathophysiology continue until negative skin scrapings and resolution of
lesions are obtained. Ivermectin at 0.2–0.3 mg/kg may be
Feline scabies or notoedric mange is caused by Notoedres
cati. This mite can also affect foxes, dogs, rabbits, and given PO or SC every 1–2 weeks for 3–4 treatments.
Doramectin can also be given at a dose of 0.2–0.3 mg/kg
humans. The lesions on humans are transient. It com- SC once. Selamectin (Revolution) applied topically once or
monly affects other cats in multiple cat residences as it is twice every 14–30 days is another option. The moxidectin/
very contagious. This mite typically occurs epizootically imidacloprid (Advantage Multi) topical product has been
in endemic areas. shown to be effective after one application.
Notoedres cati follows the same life cycle as Sarcoptes
scabei var. canis. Morphologically, it is similar to the
canine scabies mite but is smaller, the unjointed stalk is
of medium length, more striations are present on the Cheyletiellosis
body, and the anus is dorsally oriented.
Etiology/Pathophysiology
History and Clinical Signs Cheyletiella, also known as walking dandruff, is a mite
Notoedres cati causes intense pruritus predominantly of that generally results in a dermatitis of varying severity.
the facial region. The skin becomes thickened with folds Cheyletiella parasitovorax, C. blakei, and C. yasguri are
(Figure 165.9). Crusts are yellowish and tightly adherent. the species of most concern in dogs and cats, with C. yas-
Excoriations and partial alopecia may develop. Lesions guri more likely to be found on dogs and C. blakei more
begin on pinnal edges and spread over the face and neck. likely to be found on cats, although these species are not
The paws and perineum may be affected and peripheral entirely host specific. All species are contagious, and
lymphadenopathy may occur. humans in contact with animals carrying the mite can
become transiently affected.
Diagnosis These nonburrowing mites produce ova that attach to
Microscopy of superficial skin scrapings of affected cats the dog or cat hairs. They are large mites that live in the
typically reveals several mites. Diagnosis is also achieved keratin on the surface of the skin. They have four pairs of
by identifying the eggs or fecal pellets. legs with combs and their mouthparts have characteris-
tic hooks (Figure 165.10).
Therapy
Affected and in‐contact cats should be treated. Safety must
be considered in choosing treatments. Weekly 2–3% lime

Figure 165.9 Thick crusts on the convex aspect of the pinna of a
cat with chronic notoedric mange. Source: Courtesy of Dr Clarissa Figure 165.10 Cheyletiella yasguri mite; note the characteristic
Pimentel de Souza. hooks of the accessory mouthparts.