14. Cattle Arthropods

Question 1

What is the basic life cycle of mites?

Answer 1

Adults on host > eggs > larvae > nymphs
All on host
Life cycle complete in <10-14 days

Question 2

What is the chorioptes pretarsus?

Answer 2

little trumpets on short, unjointed stalks. Little suction cups

Question 3

What is the psoroptes pretarsus?

Answer 3

pedicel
trumpets on LONG, JOINTED stalks

Question 4

What is a summary of chorioptes mites?

Answer 4

Found in winter typically, bc they are crowded together in pens
Can have mild-severe localised pruritus (tail head, escutcheon, coronary bands), alopecia, oozing, crusting, +/- ulders
dx- skin scraping
transmission - direct contact and fomites

Question 5

What is a summary of psoroptes?

Answer 5

Very, very rare in CAD
typically in winter in Europe
severe generalized pruritus
causes hairloss, erythema, thickening, exudation, pruritus
dx - deep skin scrape
transmission - direct contact and fomites

Question 6

What are the ixodid (hard) ticks of cattle

Answer 6

Dermacentor variabilis (american dog tick)
3-host, SK and East, adults on cattle in May-June
Dermacentor andersoni (rocky mountain wood tick)
3-host, W of SK (mainly BC), adults on cattle in spring
Toxin from adult females associated w/ tick paralysis
Transmits anaplasma marginal among cattle

Question 7

What is the dermacentor albipictus?

Answer 7

Moose tick
1-host, anywhere you have cervids (especially moose)
Larvae, nymphs, and adults all on one host

Question 8

What is the life cycle of dermacentor albipictus?

Answer 8

Mar-Apr: Fed and Bred female falls to ground
June: eggs are laid
Sept-Oct: larvae climb onto plants and wait for hosts to pass by
Sept-Nov: larva to nymph
Oct-Feb: nymph to adult
Feb-march: adults feed and mate

Question 9

How do we diagnose ticks on cattle?

Answer 9

direct observation/clinical appearance/season of the year
Easily ID to genus level (be on the look out for invasives

Question 10

How do we tx and control ticks on cattle?

Answer 10

Generally not managed (Unless paralysis)
Mgmt: fence cervids out, don’t graze known tick habitat in spring (d. andersoni) or fall (D. albipictus)

Question 11

What are the chewing and sucking lice of cattle?

Answer 11

Chewing: damalinia bovis
Sucking:
Haematopinus eurysternus
Lingognathus bituli
Solenopotes Capillatus

Question 12

What is the life cycle of lice?

Answer 12

Entire life cyle done in a few weeks, and on host.
Feeds as adult > eggs (nits) onto hairs > nymph and feeds > adults

Question 13

How do we dx lice in cattle?

Answer 13

hx and clinical appearance
finding lice and nits
Most common in winter bc of close contact. Often asymp(carriers), causes hairloss, irritation, pruritus, dandruff, anemia
nits on base of hair, recovery and Id. of adult lice

Question 14

How do we treat lice in cattle?

Answer 14

variety of drugs available for chewing and sucking lice
residual effects often mean re-treatment not necessary
Highly contagious (treat all in herd)

Question 15

What bot flies are found in cattle?

Answer 15

hypoderma bovis and hypoderma lineatum

Question 16

What is the basic life cycle of bot flies?

Answer 16

They are adults in enviro > eggs on host > larvae IN host > Pupae in enviro
Lifecycle approx. 1 year

Question 17

What is the lifecycle of hypoderma bovis?

Answer 17

L3 exit through skin in spring, become pupae in enviro and as adults they lay eggs on hair, L1 hatch in 1 wk, migrate through spinal canal as L1 in late winter >L2 >L 3

Question 18

What is the lifecycle of hypoderma lineatum?

Answer 18

L3 exit thru skin in spring > mature to pupae >adults in enviro >eggs on hairs >L1 hatch in 1 week and migrate thru wall of esophagus > Late winter L1 arrive under skin of back > L2 >L3

Question 19

How do we dx and control H. bovis and H. lineatum?

Answer 19

detection of L3 on dorsum or @ necropsy - serology during winter (and only rarely seen these days bc of highly effective tx)
Targeted systematic tx (whole herd) In Fall before L1 have set up in spinal cord or esophagus with ML
Legislation control programs and effective tx have reduced the occurrence of hypoderma spp in W. CAD and elsewhere int he world

Question 20

What are the biting and feeding flies of cattle?

Answer 20

Blood-feeding: simulium spp (black fly), haematobia irritans (horn fly)
Secretion-feeding: musca autumnalis (face fly)

Question 21

What is the life cycle of the simulium spp?

Answer 21

Adults mate > lay eggs in fast-flowing water > larvae hatch and attach to rocks and vegetation > larvae pupate > pupare hatch to release adult flies, which float to surface in an air bubble > adult females feed

Question 22

What is the pathogenesis and control of simulium?

Answer 22

blood-feeding and nasty bites by females, attack in swarms
allergic reactions, severe pruritus - even anaphylaxis and death
vectors for several important pathogens (onchocerca spp)
several insecticides approved in CA for black fly control
Biological larvicides (ex. bacillus thuringiensis israelensis - Bti) or their toxins

Question 23

What is the lifecycle of haematobia irritans (horn fly) and musca autumnalis (face fly)

Answer 23

Horn flies: feeds on blood
Face flies: feed on ocular and nasal secretions
Female layes eggs in fresh cattle feces > L3 larval stages > larvae pupate > adults emerge from pupal cocoons >infect cattle
Not, can be several generations in a summer

Question 24

What is the pathogenesis of bitting flies in cattle?

Answer 24

Harrassment (common)
Anemia (rare)
Dermatitis/local infection
Hypersensitivity
pathogen transmission

Question 25

How do we control biting flies in cattle?

Answer 25

Mgmt: site selection for grazing vs maure piles
Eliminate arthropod breeding sites (water)
larvicidal tx’s of enviro (chemical, and biological)
Topical repellents and insecticides: sprays, wipes, powders, ear tags, back rubbers (Malathion, pyrethroids, permethrin) - pesticides, do not use off label, horn flies resistant to organophosphates and pyrethroids
wound care to prevent myasis