36 (257)

3 : Ectoparasitic skin diseases

Cheyletiella blakei

Figurę 3 : e : Cheyletiella blakei (x40)

(courtesy of ENV Parasitology Laboratory, Lyon)

Cat (occasionally man, dog and others). Found on the skin surface (rarely at the entrance to the ear canal).

Oval-shaped hexagonal body 300-500 pm. A transverse groove separates two groups of legs (1-2 and 3-4).

Long legs, each with a comb-shaped bristle (empodium) at the end.

Very well-developed rostrum with a dorsal M-shaped peritreme and two terminal pedipalps terminating ventrally in prominent, curved hooks. Species identification rests on the shape of a broad-based, ovoid, sensory organ (solenidion) (3.5 pm) on genu I of the adult mite. Eggs: 120-130 pm, sometimes a cocoon of loose filaments.

Trombicula (Neotrombicula) autumnalis (parasitic larvae)

Cat, dog, many other hosts including man. Found on the skin surface. Oval-shaped. Orange-red colour 200-500 pm.

Pointed rostrum with 2 lateral pedipalps terminating in claws.

3 pairs of long legs

Dorsally: 1 pentagonal shield and 5 long, feathery bristles on the body and legs.

Figurę 3 :f: 6-legged Trombicula autumnalis larva (x40)

Demodex spp.

Very elongated (vermiform).

Short, square rostrum - short legs - epimeres joined at the midline to form a median longitudinal bar.

Demodex cati

Cat. Found in the pilo-sebaceous unit, sometimes the dermis and ear canal. Very elongated 150-250 pm (a particularly long form found in the ear canal).

Finely-striated opisthosoma, twice as long as the prosoma.

Figurę 3: g: Demodex cati (x400) (courtesy of D.N. Carlotti)

Demodex gatoi

Cat. Found in the epidermis (homy layer) Prosoma almost as long as the opisthosoma.

a*

Figurę 3 :h: Demodex gatoi (x400) (courtesy of D.N. Carlotti)

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