Ticks and Tick-borne Disease Flashcards
What are the features of ticks and how do they differ from insects?
Ticks are arachnids, NOT insects. Cephalothorax and abdomen, or completely fused body. 8 legs. NO antennae, and NO wings.
What are some features of soft ticks (Argasidae)?
Mouth parts cannot be seen from dorsal view. NO scutum. Take multiple, small blood meals. Lay multiple batches of eggs.
What are some features of hard ticks (Ixodidae)?
Mouth parts are visible from dorsal view. Have scutum, but females only have partial scutum. Feed for approx. 1 week, lay ONE large batch of eggs (>20000). Sexual dimorphism.
Palp
Appendage found on the mouth (capitulum) of invertebrates. DOES NOT go into the skin when tick feeds.
Hypostome
Serrated edges on the mouthparts (capitulum), which help anchor the tick into the skin.
How many legs do tick larval stages have?
6
How many legs do tick nymphs have?
8
How many nymphal stages do soft and hard ticks have?
Soft ticks: 2 or more
Hard ticks: Only 1
Argas
Soft tick sp.
Feeds on birds and bats.
Morphology: Flat body and suture line!
Ornithodoros
Soft tick sp.
Feeds on mammals.
Round body, NO suture line. Long, well-developed mouth parts.
Otobius megnini
Soft tick sp.
Feeds on cattle and horses.
Nymphal tegument is spiny. Short mouth parts (NO adult feeding).
Ixodes
Black-legged tick.
White-tailed deer and livestock, plus other animals.
Eastern USA
Anal groove in FRONT of anus.
Amblyomma americanum
Lone Star Tick
SE USA
Wide host range.
Anal groove behind anus
Amblyomma maculatum
Gulf Coast Tick
SE USA
Cattle
Anal groove behind anus
Dermacentor variabilis
American Dog Tick NOT out west. Canine Capitulum base does NOT laterally protrude. 7 caudal festoons.
Dermacentor andersoni
Rocky Mountain Dog Tick
Everywhere that D. variabilis is NOT located.
Deer, cattle, and sheep.
Morphology same as D. variabilis.
Rhipicephalus sanguineus
Brown Dog Tick
Does NOT tolerate cold weather.
Base capitulum protrudes laterally. Festoons present and anal groove.
Rhipicephalus (Boophilus) annulatus
Cattle Tick Eradicated from USA. Cattle Same capitulum as R. sanguineus, NO festoons. REPORTABLE DISEASES!!!
Rhipicephalus (Boophilus) microplus
Southern Cattle Fever Tick Eradicated from USA Wider host range than R. annulatus. Same as other Boophilus. REPORTABLE!!
Haemophysalis
Rabbit Tick
WIdely distributed.
Rabbits
Second segment of palp wider than capitulum base.
Tick poisoning/toxicosis
Argas soft ticks.
Dermacentor and Amblyomma
Acute ascending flaccid paralysis caused by toxin in tick saliva.
Powassan encephalitis transmitted by:
Ixodes spp.
Nairobi Sheep Disease transmitted by:
Various hard tick spp. REPORTABLE!!!
Causes hemorrhagic gastroenteritis.
African Swine Fever transmitted by:
Ornithodoros soft tick.
REPORTABLE!!! Systemic hemorrhagic disease.
Lyme Disease transmitted by:
Ixodes scapularis –> Eastern US
Ixodes pacificus –> Western US
Causative agent: Borrelia burgdorferi
Tularemia transmitted by:
Dermacentor and Amblyomma americanum.
Agent: Francisella tularensis
Mid-west disease.
Heartwater transmitted by:
Amblyomma
Reportable!!!!
Agent: Ehrlichia ruminantium
Canine granulocytic ehrlichiosis transmitted by:
Amblyomma
Agent: Ehrlichia ewingii
Tropical Canine Pancytopenia transmitted by:
Rhipicephalus sanguineus
Ehrlichia canis
Canine cyclic thrombocytopenia transmitted by:
Rhipicephalus sanguineus
Anaplasma platys
Granulocytic anaplasmosis
Ixodes spp.
Anaplasma phagocytophilum
Bovine Anaplasmosis
Dermacentor –> Western US
Rocky Mountain Spotted Fever
Dermacentor
Rickettsia rickettsi
Hepatozoonosis
Amblyomma maculatum (severe)/Rhipicephalus sanguineus (mild).
Ingestion of tick vector
Onion skin cysts. Death 1-2 yrs PI, if untreated.
Theileriosis
Cytauxzoon felis (Amblyomma) Theileria equi (REPORTABLE)
Babesiosis
B. canis/B. gibsoni –> R. sanguineus
B. caballi –> Dermacenter, Hyalomma, Rhipicephalus. REPORTABLE!!!
B. bigemina/B. bovis –> Rhipicephalus spp.
REPORTABLE!!!!
Features of Mites
Arachnids
Several nymphal instars.
Sarcoptes scabiei
Scabies mite --> Sarcoptic mange ONE species w/ host adapted variants WIDE host range (cats are rare) Alopecia, prurities, self-tramua, secondary infections. BURROWS DEEP INTO SKIN
Sarcoptic mange
Dog –> Itch Mite. Lat elbows, hocks, pinna
Cattle –> Barn Itch. Abdomen, neck, med hind legs
Sheep/Goats –> Head Scab. Face, ears, ventrum (REPORTABLE)
Horses –> Neck, shoulders, face (REPORTABLE)
Pigs –> Ears, back
Notoedres cati
Notoedric Mange
Wild and domestic felids
Head and neck, similar to sarcoptic mange.
Psoroptes spp
P. cuniculi –> Common ear mite.
Spp in large animals are REPORTABLE!!!
Back, neck, tail head, and shoulders.
Chorioptes spp
Foot and tail mange of large animals. MOST COMMON
Mild to no clinical signs.
Otodectes cynotis
Ear mites.
Zoonotic
Trauma is usually bilateral
Demodex
NOT zoonotic!!
Species specific in hair follicles.
Immunosuppression may cause overgrowth.
Squamous and papulonodular disease.
Cheyletiella
“Walking dandruff”
Dogs/cats
Pneumonyssoides
Canine nasal mite
Rhinitis/hyperemic mucosa.
Fleas
Blood feeders w/ host preference.
Bilaterally flattened, chitinized, wingless.
Cause direct and indirect disease.
Lice
Suborders:
Mallophaga - Chewing/Biting Lice
Anoplura - Sucking Lice
HOST SPECIFIC!!!!!
