More about…Ectoparasites

Laboratory Procedures

Remember Ectoparasites?

Major Classes of Ectoparasites

Arthropods Insects Arachnids

Insects

Trichodectes canis (Biting louse) Linognathus setosus (Sucking louse) Ctenocephalides (Flea) Cuterebra (Rodent Bot Fly)

Trichodectes canis (Biting louse)

Found as Felicola sustratus in the cat Cause roughened hair coat, itching and

dermatitis May act as intermediate host to Dipylidium

caninum

Linognathus setosus (Sucking louse of dogs) Causes skin irritation, itching, dermatitis,

alopecia, anemia, roughened hair coat Usually transmitted by direct contact, but

all life stages may be transmitted by fomites

Are species specific

Ctenocephalides (Flea)

Infest dogs and cats Vector for Dipylidium caninum, tularemia,

plague, etc. Die at temperatures below 20° F for 48

hours or at temperatures above 120° F for several days

Over 200 species of fleas worldwide Severe infestations can cause anemia

Flea Life Cycle Eggs laid at rate of up to one per hour After about two days, larvae hatch and feed

on any organic material for 5-15 days. (Preferred meal is “flea dirt”)

Before becoming adults, larvae spin a cocoon and develop into an adult flea. Adult will remain in pupa until they sense vibration or increase in CO2, causing them to emerge and find their host.

Adult flea

Cuterebra (Rodent Bot Fly)

Infests rodents, companion animals and occasionally humans

Larval stage that infests skin Acts as an irritant Migration may be fatal Have a cutaneous lump with a breathing hole Use care when extracting as crushing larva may

result in anaphylaxis

Arachnids

Sarcoptes scabiei (Scabies) Demodex canis (Demodectic mange) Otodectes cynotis (Ear mites) Cheyletiella (Walking dander mite) Rhipicephalus sanguineus (Brown dog tick) Dermacentor variabilis (American Dog tick) Amblyomma americanum (Lone Star tick)

Sarcoptes Scabiei (Scabies)

Found as Notoedres cati in cats Causes intense itching, dry and thickened

skin. Is contagious to humans and other pets Mites burrow under the skin so may be

difficult to diagnose Diagnose through a skin scraping Usually have “ventral blowout”

Demodex canis (Demodectic Mange)

Rare in cats Causes areas of alopecia on head, neck, forelimbs. Can be localized or generalized. Diagnosed with skin scraping. (May also pluck hair

from root) Is not contagious Small numbers considered normal on skin flora Genetic predisposition

Otodectes cynotis (Ear mites)

Intense pruritis of the ear canal. Can be found on any area of the body Feed on epidermal debris and are easily

transmitted

Cheyletiella (Walking Dander mite)

Causes mild alopecia and pruritis May cause dermatitis in humans Ingest keratin debris and tissue fluids Have enormous hook-like accessory

mouthparts Are visible to the naked eye

Rhipicephalus sanguineus (Brown dog tick)

Vector for canine babesiosis and canine ehrlichiosis

May cause anemia or tick paralysis when found in large numbers

Dermacentor Variabilis (American Dog Tick)

Feeds on small mammals but can also feed on dogs and humans

Vector for Rocky Mountain Spotted Fever, tularemia, and can cause tick paralysis in animals and humans

Anblyomma americanum (Lone Star tick)

Gets name from white spot on apex of scutum

Feeds on animals and humans

May be vector for Rocky Mountain Spotted Fever and tularemia.

Vector of Ehrlichia