CHAPTER 19 DEMODICOSIS (CANINE AND FELINE) 299
Cats
Often characterized by partial to complete multifocal alopecia of the eyelids and peri-
ocular region when localized; chin, head, forelimbs, dorsal or ventral trunk, and neck;
may be generalized (Figure 19.12).Ceruminous otitis externa.
Variable pruritus.
Demodex gatoiinfections are often indistinguishable from allergic dermatitis and psy-
chogenic dermatoses; multiple cats in the household may be affected.
DIFFERENTIAL DIAGNOSIS
Dogs
Bacterial folliculitis/furunculosis (from other causes)
Allergic dermatitis (adverse reaction to food, atopic dermatitis, insect hypersensitiv-
ity)
Dermatophytosis
Contact dermatitis
Pemphigus complex
Dermatomyositis
Systemic lupus erythematosus
Epitheliotropic lymphoma (patch stage)
Cats
Allergic dermatitis (adverse reaction to food, atopic dermatitis, insect hyper-
sensitivity)
Dermatophytosis
Bacterial folliculitis
Psychogenic dermatoses
DIAGNOSTICS
May be useful for identifying underlying metabolic diseases in both dogs and cats.
FeLV and FIV serology: identify underlying metabolic diseases in cats.
Skin scrapings:
Diagnostic for finding large numbers of mites in the majority of cases
Intrascapular region may be the most productive site in the cat because the area
is not easily groomed
Superficial scrapings:D. cornei(short-bodiedD. canis: dog) andD. gatoi(cat)
Deep scrapings:D. canis(dog),D. injai(dog), andD. catiandD. felis(cat).Trichography/trichogram (hair plucks): examination of hair casts for mites; not as
reliable as scrapings (Figure 19.13).