10. Mange Flashcards
Astigmatid mites. Taxonomy
Burrowing mites: Sarcoptes, Nodoedres, Knemidokoptes
Non-borrowing mites: Psoroptes, Chorioptes, Otodectes
Burrowing mites. Species, morphology, development
- Sarcoptes, Notoedres, Knemidokoptes spp
- females burrow tunnels into the skin (for egg laying and larval development)
- may survive off host for a few days only
— - round body up to 0,4 mm, scales on the dorsal surface
- anus may be terminal (Sarcoptes, Knemidokoptes) or dorsal (Notoedres)
- short legs, 3d and 4th pairs of legs don’t project beyond the body margin
-
unsegmented pedicles
— - development for 3 weeks
- Knemidokoptes: viviparous
Non-burrowing mites. Species, morphology
- Psoroptes, Chorioptes, Otodectes
- live and develop on the skin surface
- generally have chewing mouthparts and feed on epidermal debris, Psoroptes also have piercing mouthparts and also feed on tissue fluids
- may survive off the host for a max 2-3 weeks
— - oval body, up to 0,8 mm
- long legs projecting beyond the body margin
- long, 3-segmented (Psoroptes) or short, unsegmented pedicel (Chorioptes, Otodectes)
— - development for approx 2 weeks
Mites. Clinical signs (mange)
Mange:
- dermatitis with epidermal hyperplasia
- desquamation
- crusts and scabs
- pruritus (itching), self-rubbing, hair loss
- papules, vesicles
- thickened, wrinkled skin
- secondary bacterial infection (neglected cases may be fatal)
Astigmatid mites (burrowing + non-burrowing) in horses
- Sarcoptes scabei var. equi -> sarcoptic mange (areas with short hair)
- Psoroptes spp -> psoroptic mange
- Psoroptec cunicili - otitis externa
- Psoroptes ovis - thickly haired regions of the body
-
Chorioptes bovis -> chorioptic mange (usually cold-blooded heavy breeds of horses, on lower parts of the hind limbs
—
photo: sarcoptic mange
Astigmatid mites (burrowing + non-burrowing) in cattle
Similar to horses
- Sarcoptes scabei var. bovis - sarcoptic mange (short hair parts)
- Psoroptes ovis - psoroptic mange (long hair areas)
- Chorioptes bovis - chorioptic mange (lower parts of limbs, base of tail, scrotum…)
Astigmatid mites (burrowing + non-burrowing) in sheep, goats
- Sarcoptes scabei var. ovis (caprae) - skin without fleece
- Psoroptes ovis - woolly parts - wool hanging from fleece covering, in 2-6 weeks coin to palm size lesions develop, becoming dry in the center
- Psoropres cuniculi - can be found in ears of goats (spreading over head, neck and body)
- Chorioptes bovis - lower parts, scrotum
Astigmatid mites (burrowing + non-burrowing) in pigs
Sarcoptes scabei var. suis - acute (at 3-4 weeks of age) and chronic (in adults) forms.
Spreading from the ears to the most of the body surface.
Involved areas -> hyper- and parakeratosis
Astigmatid mites (burrowing + non-burrowing) in dogs
-
Sarcoptes scabei var. canis - more important in foxes, zoonotic, highly contagious, spreading by direct contact. After incubation period (10 days to 8 weeks) from the edge of the ear, above the eyes, elbows and further to ventral parts of the body. Seborrhoea, lymphadenopathy, emancipation
— -
Otodectes cynotis - in the external ear canal -> excess of dark cerumen, purulent inflammation and discharge -> ear scratching, head-shaking
— - rarely Notoedres cati causes Notoedres mange in young dogs
Astigmatid mites (burrowing + non-burrowing) in cats
- Notoedres cati -> notoedric (face) mange. From the edge of the ear spreading over the face, neck, pцы nd tail
- Otodectes cynotis
Astigmatid mites (burrowing + non-burrowing) in birds
- Knemodokoptes gallinae -> depluming itch, loss of feathers
- Knemodokoptes mutans -> scaly leg, scales -> plaques -> crusts
- Knemodokoptes pilae -> scaly face, papillomatous skin-thickening around the beaks, later spreading to the legs
Astigmatid mites (burrowing + non-burrowing) in rabbit
- Psoroptes cuniculi -> ear canker. External ear: multilayered epidermal debris with eroded, bleeding skin underneath -> ear scratching, head shaking. Lesions may spread over the body surface
- Notoedres cati, Sarcoptes scabei - rarely
