Fleas
- Blood sucking
- Vectors – bubonic plague, intermediate host to Dipylidium caninum
- Hypersensitivity to flea saliva can cause flea-allergy dermatitis
- Flea dirt/flea dander – reddish black. Dissolves in water
- Ctenocephalides felis – dogs and cats
Ticks
- Blood sucking
- Vectors – bacterial, viral, rickettsial, protozoal diseases – including Lyme’s Disease
- Tick paralysis – neurotoxin in saliva – Dermacentorandersoni (Rocky Mt. Spotted
Fever tick) - Lifecycle: egg, 6-legged nymph, 8-legged adult
- Family Ixodidae
- Family Argasidae
Family Ixodidae
a. Hard ticks
b. Rhipicephalussanguines – Brown Dog Tick
c. Dermacentorvariabilis – American Dog tick (also does tick paralysis)
Family Argasidae
a. Soft ticks
b. Otobiusmegnini – spinose ear tick
Lice
- Spend entire lifecycle on host
- Spread by direct contact
- Eggs = nits – attach to hair shaft
- Family Anoplura
- Family Mallophaga
mily Anoplura
a. Sucking louse – elongated heads, sucking
mouth parts
b. Linognathussetosus - dog
c. Hematospinusasini – horse
d. Pthirus pubis- – human crab louse – occasionally will see dogs/cats infested
Family Mallophaga
a. Biting louse – large rounded head, mandible- like mouth parts
b. Trichodectes canis – dog
c. Felicolasubro strata – cat
d. Daemilineacaprae - goat
Family Demodex
mite
a. Non-pathogenic in small numbers
b. Host specific – not transmissable
c. 6-legged larva, 8-legged nymph, adult
d. Live in hair follicles, sebaceous glands
e. Localized demodicosis – patchy alopecia
f. Generalized demodicosis – diffuse alopecia, secondary bacterial infections
Family Sarcoptidae
a. Include Sarcoptes sp. And Notoedres sp.
b. Burrow within epidermis, intensely pruritic
c. Canine “scabies” (sarcoptic mange) caused by Sarcoptes scabieivar canis
d. Cats not affected by Sarcoptes, but Notoedrescati can cause notoendric
mange.
e. Hard to diagnose. Use lesions and distribution. Treat based on clinical signs
1) Raised rash, crustiness
2) Irritation, scratching
Canine “scabies” (sarcoptic mange) caused by Sarcoptes scabieivar canis
1) Scaling, crusting, self-trauma
2) Ears, lateral elbows, ventral abdomen harbor mites
3) May be transmitted to humans, but
considered to be self-limiting
4) Highly contagious to other dogs. Carrier states may exist.
Types of Mites
- Family Demodex
- Family Sarcoptidae
- Family Psoroptidae
- Cheyletiella sp.
- Trombicula Mites
F. Cuterebra flies
Family Psoroptidae
Family Psoroptidae
a. Include Psoroptes sp. Chorioptes sp.
Otodectes sp.
b. Mostly cattle, sheep except Otodectes
c. Live on surface of skin, species specific
d. Otodectes cynotis
Otodectescynotis
1) Ear mite
2) Causes otitis externa in dogs and cats
3) Not host specific
4) Causes irritation, dark, dry crust in the ear canals
Cheyletiella sp.
a. Walking dandruff mite
b. Skin surface
c. Relatively host specific, causes scaling and crusting
Trombicula Mites
- Chiggers
- Humans, too. Only larva are parasitic, nymphs and adults are free living
- Larva only attaches for several hours. Causes red rash
Cuterebra flies
- Eggs laid in soil of rodent burrows
- Infest rabbits, cats, occasionally dogs
- Larva penetrate host’s skin and live SQ with a fistula to outside
- Surgically removed
