Bovine Ectoparasites
Dr. Dipa Brahmbhatt MPH DVM
Chapter 13
Bovine Ectoparasites
• Limit production
• Disease
• Season:
– spring and summer
– SE Texas's all year-round
• Phylum Arthropoda
– Flies: Class: Insecta and
Order: Diptera
– Ticks, mites: Class:
Arachnida ; Order: Ixodida
Heartwater ticks shown
feeding on a cow
Bovine Ectoparasites - Taxonomy
•
•
•
Biting Flies: piercing mouthparts adapted
for blood sucking
– Horn fly: Siphona (Haematobia)
irritans
– Stable Fly: Stomoxys Calcitrans
– Horse (Tabanus sp.) and Deer Flies
(Chrysops sp.)
– Screw worm fly: Cochliomyia
hominivorax
– Gnats: Simulium and Culicoides
Non-biting Flies
– Face fly: Musca autumnalis
Myiasis
– Common cattle grub : Hypoderma
lineatum
– Northern cattle grub : Hypoderma
bovis
– Screworm: Cochliomyia hominivorax
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•
Lice
• Chewing lice: Damalinia (Bovicola)
bovis
– Sucking lice:
• longnosed cattle louse:
Linognathus vituli
• shortnosed cattle louse:
Haematopinus eurysternus
Mites
•
•
•
•
•
•
Sarcoptes
Chorioptes
Psoroptes
Demodex bovis
Mosquitoes
Ticks
Flies
• 1 pair of wings
• complete metamorphosis
• ~ 20 families of flies are of
veterinary importance
House Fly
CREDITS: J. F. Butler, University of Florida
Flies
Comparison of the horn fly to the stable fly, house fly, and
face fly. Photo: Photo: John B. Campbell, University of Nebraska-Lincoln
Face fly: Musca autumnalis:
Horn Fly: Siphona (Haematobia) irritans
• Serious pests in TX
• C.S: pain, irritation,
weight loss, low milk
production, +/- open
sores; secondary
infections
• pierces the skin to
blood feed
• persistent biter.
• Horn fly: greatest economic loss
in US cattle
Horn flies congregate along the back and sides of cattle: SMALL AVID FEEDERS
Horn Fly: Siphona (Haematobia) irritans
• Lifecycle: 10 – 14 days
– Eggs: laid in fresh (~ 10 min.
of dropping) manure.
– Larvae: hatch ~18 hours and
feed on the dung > through
3 stages in 3 - 5 days.
– Pupal stage: lasts 3 to 5 days
> adults which emerge have
a preoviposition period of 3
days.
– Mating on the host
• females can lay about
200 eggs in their lifetime
Tx: pyrethroid or organophosphate
impregnated ear-tags and pour on’s
(ivermectin): General for all
ectoparasites
Stable Flies: Stomoxys calcitrans
SMALL AVID FEEDERS
• mechanical transmitters
– anthrax
– anaplasmosis
• Like house fly but the
bayonet-like
mouthparts of the
differentiate it from the
house fly.
• both sexes: biters.
• C.S: irritation, lethargy
(blood loss in severe
cases); bite wounds and
secondary infections
• Tx: pour on’s sprays,
remove feces and
spoiled hay and grain
Horse (Tabanus sp.) and Deer Flies (Chrysops sp.)
Deer Flies (Chrysops spp.)
BOTH:
• Only females bite.
• Daytime feeders: vicious biters.
Horse (Tabanus spp.)
• painful bites: stampedes
• Transmit: Anaplasmosis, tularemia,
anthrax
Gnats
• Simulium and Culicoides
are both small gnats
that have painful bites.
Culicoides
Face Fly: Musca autumnalis
• Feeds on tears, saliva
and mucus.
• Annoying
• Mechanical carries:
– Moraxella bovis
– IBR
– Thelazia spp
(eyeworms)
Myiasis: infestation of vertebrates
by dipteran larvae (maggots)
Myiasis
TX: before esophagus/ spinal
• U.S: Cattle warbles
cord > death: Sprays and
– common cattle grub:
dips using coumaphos or
Hypoderma lineatum
phosmet, Pour-on
• LC: eggs – hair of cattle >
formulations of famphur,
maggots – skin >
fenthion, ivermectin, and
esophageal > pupa
phosmet
– northern cattle grub:
Hypoderma bovis
• LC: eggs – hair of cattle >
maggots – skin > spinal
cord > pupa
• Lifecycle: 10-12 months
• Clinical signs
– damage - tissues and hide,
reduction of weight gain
Heel flies
Myiasis
• Screwworm: Cochliomyia
hominivorax
• LC: 3 weeks: Larvae > fly will bore
into live tissue maturing
• Very pathogenic and high
mortality
– feeds exclusively on live flesh
• Eradicated in US in 1966:
introduced sterile males
– REPORTABLE: cost producers
$75 million if back in US
LICE – LOUSE: Pediculosis
LOUSE
• Entire lifecycle on host
• Transmitted: direct contact
– introduction of carrier animals
LOUSE: Mallophaga
• Chewing lice: order
Mallophaga
– Little red louse:
Damalinia (Bovicola)
bovis
• LC: 4 wks.
• Fall and winter:
brisket/leg/in between
legs
• C.S: pruritus, unthrifty
appearance and a rough
coat
Damalinia bovis, male. Courtesy of Dr.
Dietrich Barth, Merial
LOUSE: Anoplura
Linognathus vituli, female. Courtesy of
Dr. Dietrich Barth, Merial
Haematopinus eurysternus, female.
Courtesy of Dr. Dietrich Barth, Merial
• Sucking lice: order Anoplura
– longnosed cattle louse:
Linognathus vituli
– shortnosed cattle louse:
Haematopinus
eurysternus
• Head/ neck/ brisket: winter
to early spring
• LC: 4 wks.
• C.S: pruritus, unthrifty
appearance and a rough
coat, anemia (rare severe
infestation)
MITES: MANGE
Sarcoptes
Chorioptes
Psoroptes
Sarcoptes, Chorioptes, and Psoroptes can be
easily differentiated by leg stalk characteristic and
mouthparts. Speciation is more difficult and usually
requires an expert acarologist.
Mange Mites
• Sarcoptes scabiel
• Transmission: contagious,
spread by direct contact or
indirectly by fomites.
• LC: 3 weeks
• CS: head, neck, and
shoulders: pruritus is
intense, papules develop
into crusts
• Diagnosis: deep skin
scrapings
• Zoonotic and reportable
Sarcoptes scabiei var bovis, female.
Courtesy of Dr. Dietrich Barth, Merial
Mange Mites
• Psoroptes spp (most
damaging)
• LC: 3 wks.
• C.S.: Intense pruritus,
lichenification, secondary
bacterial infections, weight
loss, dec. milk production
• Signalment: calves
• Dx: skin scrapings
Psoroptes ovis, female.
Courtesy of Dr. Dietrich Barth,
Merial
Mange Mites
• Leg mange: Chorioptes spp.
• most common type of
mange in cattle in the USA
• L.C: 3 weeks
• C.S: papules, crusts, and
ulcerations on the legs and
can spread to the udder,
scrotum, tail, and perineal
area
• Reportable in some states
Chorioptes bovis, female. Courtesy
of Dr. Dietrich Barth, Merial
Mange Mites
• Demodex bovis
• C.S: damages hide,
follicular papules
and nodules:
withers, neck, back,
and flanks
• Dx: deep skin
scrapings
• Usually resolves with
time
Mange lesions
Mosquitoes
• Mosquitoes are small
insects: piercing-sucking
mouthparts
• Female mosquitoes
suck blood
• C.S: painful bites,
unthriftiness, and
occasionally death by
suffocation or heavy
blood loss
TICKS
TICKS
• Body is a fusion of the thorax and abdomen produces a saclike, leathery appearance.
• Class Arachnida
• Bears recurved teeth
• 4 developmental stages: egg, 6-legged seed or larval stage, 8legged nymphal stage and 8-legged adult.
Babesiosis
• Babesiosis: Red water fever
– Boophilus annulatus
• Vector for Babesia bigemina:
PROTOZOA
– L.C: May/June, moving cattle to new
pasture
– Signalment: Cattle, small ruminants,
water buffalo, reindeer, American bison
– C.S: inflammation, itching and swelling
at the bite site, regenerative anemia:
red urine, abortion, unthrifty,
neurological signs (seizures, blindness)
– Dx: blood smear
– Tx: tetracycline
Babesia/ Piroplasmosis in blood smear:
Wright or giemsa stain
Anaplasmosis
• Transmission
– Vector borne
• Ticks: Dermacentor
andersoni, Boophilus,
Rhipicephalus , Ixodes ,
Hyalomma , and
Ornithodoros
– blood sucking flies and
mosquitoes.
– mechanical vector: scalpels,
needles, and tatoo
– Organism: Anaplasma
marginale, rickettsial
• Signalment: cattle, sheep, goats,
wild ruminants; > 3 yrs; carriers
for life, bos taurus
RMSF
Anaplasmosis
• C.S: progressive anemia
• peracute
• Acute: febrile, lose
condition rapidly,
anorexia, dec. milk
production, GI:
constipation, depressed
rumination, brown urine
(hemoglobinuria does
not occur), abortions,
cerebral anoxia >
aggressive
• Tx: tetracycline
Anaplasma marginale infection in bovine blood, WrightGiemsa, 100X oil immersion. Intracellular organisms appear
as basophilic, spherical inclusions that are generally
located near the margin of erythrocytes. Frequent
echinocytes are present. The hemat Courtesy of Dr. John W.
Harvey
References
• Holtgrew-Bohling, Kristin, Large animal clinical procedures for veterinary
technicians, 2nd edition, Elsevier, 2012
• http://edis.ifas.ufl.edu/ig130
• http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document1932/VTMD-7000web.pdf
• http://www.cfsph.iastate.edu/Factsheets/pdfs/bovine_babesiosis.pdf
• http://vetmed.iastate.edu/vdpam/extension/beef/currentevents/anaplasmosis-iowa
• 5 minute veterinary consult: Ruminant
• http://www.vet.kstate.edu/depts/vmth/agpract/articles/Common_Flies.pdf
• http://www.uwyo.edu/vetsci/courses/patb_4110/27/class_notes.htm#Ectoparasites_of_cattle
• www.vetmed.isu.edu
References
• http://www.vetmed.ucdavis.edu/vetext/INFDA/INF-DA_HEARTWATER.HTML
• http://www.animalhealth.bayer.com/3380.0.h
tml
• http://parasitology.cvm.ncsu.edu/quiz/rumina
nt/exam3/ruminantquizFQ.php
• http://vetpda.ucdavis.edu/parasitolog/Parasit
e.cfm?ID=40