Ascrids Flashcards
Ixodes spp.
Common name: Black-legged tick or Deer tick
Host: Adult - dogs and cats; larvae - small rodents
Characteristics: Anal groove forms an arch anterior to anus , no festoons
Site of Infection: Skin
Life cycle: Three-host life cycle; larvae feed in the fall
Pathogenesis: paralysis in animals; allergic reaction to bites; tramission of Lyme disease and ehrlichia to animals; transmission of anaplasma phagocytoplium and babesia to humans
Dermacentor spp.
Common name: American dog tick or Rocky mountain wood tick
Host: Cats dogs, humans and small rodents
Characteristics: rectangular basis capituli
Site of Infection: skin - around head and neck
Life cycle: Three-host tick
Pathogenesis: Transmission of Rocky Mountain Spotted Fever, Tularemia, Babesia, Tick paralysis
Rhipicephalus sanguineus
Common name: Brown Dog Tick or Kennel Tick
Host: dogs, cats, and humans
Characteristics: Hexgonal basis capituli, inornante scutum
Site of Infection: skin between toes and ears or back of neck
Life cycle: Three-host tick
Pathogenesis: Tramission of babesia canis and Ehrlichia & Rocky Mountain Spotted Fever
Ambylomma spp.
Common name: Lone Star Tick Host: Dogs, cats, humans
Characteristics: very long palps; single white spot on female scutum
Site of Infection: head, ears and neck
Life cycle: Three-host tick
Pathogenesis: Painful bites –> itchinging; Transmission of ehrlichiosis, tularemia, Rickettsia, Borrelia, coxiella; tick paralysis in humans and dogs
Rhipicephalus spp.
Common name: Blue tick or Cattle Fever Tick
Host: Cattle
Characteristics: Hexagonal basis capituli & short palps
Site of Infection: ventral aspect of body
Life cycle: One-host tick
Pathogenesis: Transmission of Texas Cattle fever or bovine piroplasmosis and gallsickness
Otobius spp.
Common name: Spinose ear tick
Host: Wild and domestic animals
Characteristics: mouthparts are not visible dorsally
Site of Infection: ears
Life cycle: One-host tick
Pathogenesis: severe inflammation and rupture of ear drum, anaemia and loss of condition
Argas spp.
Common name: Fowl tick
Host: Domestic and wild fowl
Characteristics: leathery and textured body; soft tick - mouthparts are not visible dorsally
Site of Infection: under the wing
Life cycle: One-host tick
Pathogenesis: anaemia, weight loss, depression, toxaemia, paralysis; transmission of spirochetosis and Rickettsial organisms
Sarcoptes scabiei
Common name: Mange mite or itch mite, or scabies mite
REPORTABLE in cattle
Host: Dogs, Pigs, cattle (most severe mange in cattle), and humans
Characteristics: round body with many spines
Site of Infection: ears, ventral thorax and abdomen, inner ear, and tail
Life cycle: ELNA
Pathogenesis: Erythema, scale, and crust formation –> downgrading of hide)
Notoedres cati
Common name: Noteodric cat mite
Host: feline
Characteristics: smaller than sarcoptes
Site of Infection: head
Life cycle: Females are usually found in aggregations; one-host tick
Pathogenesis: dry, encrusted, scaly lesions on the edges of the ears and face –> thickened appearance
Knemidocoptes spp.
Common name: Scaly leg mite or scaly face mite
Host: Domestic avian species
Characteristics: Resembles sarcoptes scabiei
Site of Infection: under scales of legs, comb, wattles and neck
Life cycle: entire life cycle is spent on the host
Pathogenesis: Inflammation and keratinization of skin and legs; lameness –> malformation of feet; can result in emaciation and death
Chorioptes bovis
Common name: Foot mange, leg mange, or itchy heel
Host: Cattle, sheep, and goats; sometimes in horses
Characteristics: Rounded mouthparts
Site of Infection: back of hind legs and tail head
Life cycle: ELNA (PPP 10 days); all stages on host
Pathogenesis: damage to hide, lesions are localized, pruritis, alopecia, and crusting skin formation
Psoroptes ovis
Common name: Sheep scab mite
REPORTABLE
Host: Sheep and cattle
Characteristics: Oval body shape; pointed mouthparts
Site of Infection: throughout the body Life cycle: ELNA; all stages on host
Pathogenesis: intense itching –> ragged wool; provides route for secondary bacterial infection
Otodectes cynotis
Common name: Ear mite
Host: Dogs, cats, ferrets, fox, rabbit,, humans (rare)
Characteristics: long legs that extend past body margin
Site of Infection: External ear canal
Life cycle: ELNA; all life cycle in ear
Pathogenesis: dry waxy parchment-like material in ears with large number of mites; common cause of otitis externa
Cheyletiella yasguri
Common name: Walking dandruff
Host: Dogs, cats, rabbits, humans
Characteristics: has a “waist”
Site of Infection: back of the head
Life cycle: Spent entirely on host
Pathogenesis: Exfoliative dermatitis –> skin sales are shed into the hair and giving it a powdery appearahce; easily transmitted to humans
Demodex canis
Common name: Follicle mite or demodectic mange mite
Host: Dog
Characteristics: “cigars with legs” - tapering body with 4 pairs of stumpy legs
Site of Infection: hair follicles and sebacceous glands
Life cycle: ELNA; all life cycle is spent in hair follicles
Pathogenesis: localized demodicosis –> alopecia, erythema, *no pruritus; generalized demodicosis (difficult to treat)
Dermanyssus gallinae
Common name: Red mite, roost mite, poultry mite
Host: Domestic fowl
Characteristics: Scales, spines, and setae are observed; spider like long legs, body becomes red/black after blood meal
Site of Infection: skin
Life cycle: ELNA; night mite - only on host during the night
Pathogenesis: weight loss, reduced egg yield, increase transmission of secondary infections
Ornithonyssus spp.
Common name: Northern fowl mite or Tropical fowl mite
Host: Chickens (most common mite in poultry), birds, and humans
Characteristics: spider like with long legs; body is red/black after blood meal
Site of Infection: around feathers and vent areas
Life cycle: ELNA; on host during night and day
Pathogenesis: transmission of ecephalitis, fowl poxvirs, etc.
