Cattle & Sheep Ectoparasites Flashcards
What is the prevalence of Chorioptes?
common in Canada
Difference between surface & burrowing mites?
What is the seasonality of chorioptes?
winter
What disease is caused by Chorioptes?
SEVERE LOCALIZED PRURITUS
- tail head, escutcheon, coronary bands
- alopecia, oozing, crusting, +/- ulcers
What animals do Chorioptes transmit between?
cattle, sheep, & horses
How do you treat for Chorioptes?
- treat all in contact hosts
- topical or pour on
- resistance to organophosphates
What is the prevalence of psoroptes?
very rare in Canada
What is the seasonality of psoroptes?
winter
What kind of disease does psoroptes cause?
SEVERE GENERALIZED PURITUS (SHEEP SCAB)
- papules & pustules, erythema, alopecia, oozing, crusting, thickening
- can be fatal (self trauma)
Does Psoroptes transmit between species?
No. Host specific strains
How do you treat psoroptes?
- treat all in contact conspecifics
- systemic
How prevalent is sarcoptes?
rare in Canada
what kind of disease does sarcoptes cause?
SEVERE PRURITUS, HAIR LOSS, THICK SKIN
How is sarcoptes transmitted?
- cattle to cattle
- HIGHLY CONTAGIOUS
- fomites may play a role
How do you treat sarcoptes?
- need multiple deep skin scrapings & treat the whole herd
What is the prevalence of Demodex?
- part of skin flora
- demodectic mange not common
What kind of disease does demodex cause?
- not contagious
- happens if there is immunological/ underlying problem
What are the hosts of demodex?
cattle
How do you treat for demodex?
only the affected animals!
How do we diagnose mange in cattle & sheep?
- history, SEASON, & clinical appearance (degree & extent of pruritis)
- SURFACE MITES: KOH digest of superficial skin scraping, crusts; serology in sheep & cattle (for Psoroptes)
- BURROWING MITES: deep skin scraping
How do we treat & control mange in cattle & sheep?
- ELDU macrocyclic lactones in fall (pour-ons for Chorioptes, parenteral for Psoroptes, Sarcoptes, & Demodex)
- fomites & chutes should be steam cleaned & treated w/ acaricide
Who do you treat for mange in cattle & sheep?
What bacterial species cause anaplasmosis?
- Anaplasma marginale (bovine anaplasmosis)
- Anaplasma bovis (monocytic anaplasmosis)
What are the reservoirs of anaplasmosis?
- persistently infected cattle & bison
- ticks
- deer & elk
What are the vectors of anaplasmosis?
- ticks (biological): Dermacentor andersoni, Dermacentor veriabilis, Dermacentor albipictus?
- biting flies (mechanical): tabanids, stable flies
- fomites (iatrogenic)
what are the clinical signs of anaplasmosis?
- none
- weight loss
- hemolysis
- jaundice
- splenomegaly
- abortion
- lethargy
- death (especially adult cows)
- (mortality rate >30%)
How do you diagnose anaplasmosis?
- location, season, signalment, clinical signs, necropsy
- blood smears (active infections)
- ELISA SEROLOGY (CARRIERS): outbreak in bison in 2000 in SK, 35 positive of 730 cattle tested by PDS, outbreaks in cattle in SK, MB, ON
- CFIA: IMMEDIATELY NOTIFIABLE DISEASE
- PROVINCIALLY REPORTABLE TO CVO BC, AB, SK, MB
How do you manage anaplasmosis?
- tick & biting fly & iatrogenic prevention
- NO APPROVED VACCINES OR TREATMENTS
- live & killed vaccines tried elsewhere (prevent clinical disease, but not infection; complicated by multiple strains/genotypes)
- NO ANTIMICROBIALS WILL CLEAR CARRIER ANIMALS
- antimicrobials may reduce disease (chlortetracycline (feed additive) or oxytetracycline (injectable))
What are the 3 types of flies (Diptera) of cattle & sheep?
- biting/feeding flies
- bot flies (OBLIGATE myiasis flies)
- keds & myiasis flies
What are the characteristics of a biting/feeding fly & some examples?
- feed on secretions or blood
- larval development in aquatic environments
- Simulium spp. (black flies), Haematobia irritans (horn fly), Musca autumnalis (face fly)
What are the characteristics of a bot fly & some examples?
- invasion of living tissue as part of life cycle
- Hypoderma bovis, H. lineatum (warbles, cattle grubs)
- Oestrus ovis (sheep nasal bot)
What are the characteristics of a ked &/or myiasis fly?
- open wounds - flies lay eggs
- v important in sheep
Which biting/feeding flies are blood-feeding?
- Simulium spp (black fly): important for transmission of Onchocerca
- Haematobia irritans (horn fly): major pest of cattle, cluster on back & sides
Which biting/feeding flies are secretion-feeding?
- Musca autumnalis (face fly): important for transmission of MORAXELLA (PINK EYE)
What is the common name for Dermacentor variabilis?
American dog tick
How many hosts does Dermacentor variabilis have?
3 host tick
What is the distribution for Dermacentor variabilis?
SK & east
What is the relevance of Dermacentor variabilis?
- adults on cattle in May-June, TRANSMITS ANAPLASMA MARGINALE among cattle
What is the common name for Dermacentor andersoni?
Rocky Mountain Wood Tick
How many hosts does Dermacentor andersoni have?
3 host tick
What is the distribution for Dermacentor andersoni?
West (mainly BC)
What is the relevance of Dermacentor andersoni?
- adults on cattle in spring
- TRANSMITS ANAPLASMA MARGINALE
- toxin from females - TICK PARALYSIS
What is the common name for Dermacentor albipictus?
Winter tick
How many hosts does Dermacentor albipictus have?
1 host tick
What is the distribution of Dermacentor albipictus?
anywhere you have cervids
What is the relevance of Dermacentor albipictus?
- adults, nymphs, & larvae on cattle
- MAY TRANSMIT ANAPLASMA MARGINALE
What is the common name for Otobius megnini?
Spinose ear tick
What is special about Otobius megnini?
it is a SOFT TICK
How many hosts does Otobius megnini have ?
1 host
What is the distribution of Otobius megnini?
BC
What is the relevance of Otobius megnini?
- not associated w/ paralysis or pathogen transmission
- ONLY LARVAE & NYMPHS ARE PARASITIC (adults are free-living)
What are the invasive species of ticks we care about?
- Haemaphysalis longicornis (Asian long horned tick): initially in Virginia, now in multiple US states, may transmit many diseases, females can reproduce w/o a male
- Amblyomma americanum (lone star tick) - South US & now Canada, red meat allergy
Who are Simulium spp. (black flies)?
Biting/feeding flies & blood-feeding
- transmission of Onchocerca
- develop in flowing water
- salivary toxin - vascular damage
Who are Haematobia irritans (horn flies)?
Biting/feeding flies & blood-feeding
- major pests in cattle, cluster on back & sides
- develop in fresh cattle feces
- transmission of Stephanofilaria (skin lesions in cattle)
Who are Musca autumnalis (face flies)?
Biting/feeding fly & secretion-feeding
- transmission of Moraxella (pink eye) & Thelazia
- develop in fresh cattle feces
- ADULTS HAVE NON-PIERCING MOUTHPARTS, MOPS UP SECRETIONS W/ LABELLA
Who are Hypoderma spp (cattle warbles)?
Bot fly (obligate myiasis)
- bumble-bee like adults in summer
- adults dont feed - no mouth parts
- lay eggs on hair, hatches L1 which burrows into skin & MIGRATES DURING THE WINTER
-> H. bovis: fat around spinal camal
-> H. lineatum: esophagus submucosa
-> PROBLEM if killed during winter! (fall ideal)
Who are Oestrus ovis (nasal bots of sheep)?
Bot fly (obligate myiasis)
- Adults don’t feed, larvae migrate in nose
Who are Melophagus ovinus?
Sheep ked
- wingless (confused with louse) -it’s a fly
Who are the fly strike flies?
Myiasis flies
- multiple spp - primary or secondary
- facultative myasis, worst season is summer
What is the basic lifecycle of mites?
What is the lifecycle of Dermacentor albipictus?
What is the lifecycle of lice?
lifecycle is entirely on host - off host survival is limited. highly host specific!
What is the Simulium spp. (blackfly) life cycle?
What is the life cycle of Haematobia irritans (Horn fly) & Musca autumnalis (Face fly)
What is the life cycle of Cattle Warbles (Hypoderma spp.)?
What is the lifecycle of Hypoderma bovis?
What is the lifecycle of Hypoderma lineatum?
What is the lifecycle of Oestrus ovis?
What is the lifecycle of Melophagus ovinus?
How do we diagnose lice in Cattle & Sheep?
- hx & clinical appearance
- often asymptomatic (carriers)
- hair loss, irritation, pruritis, dandruff, anemia
- nits on base of hair, recovery, & ID of adult lice
How do we treat lice in Cattle & Sheep?
pour-on macrocyclic lactones (ML)
- many reports of lack of efficacy emerging in W. Canada
- BETTER FOR SUCKING vs chewing lice
- pyrethroid pour-on (adults) / insect growth regulators (inhibit egg hatching)
Diagnosis & control of Hypoderma bovis & lineatum?
- diagnosis: detection of L3 on dorsum or at necropsy
- prior to hide damage: serology during winter
- targeted systematic treatment (whole herd) IN FALL (before L1 have set up in the spinal cord or esophagus) with ML
- if must treat in winter, low dose of ivermectin SLOW KILLS L1 when in spinal cord or esophagus (risk for resistance)
- legislated control programs & effective treatments have reduced the occurrences of Hypoderma spp. in western Canada & elsewhere in the world
- if vigilance is relaxed or less efficient products are used, these parasites would once again become an issue
Which pathogens are transmitted by Simulium spp.?
- vectors for several important pathogens (Onchocerca spp)
Which pathogens are transmitted by mosquitoes?
IH for peritoneal nematode Setaria
Which pathogens are transmitted by Haematobia irritans?
IH for nematode Stephanofilaria (skin lesions in cattle)
Which pathogens are transmitted by Musca autumnalis?
IH for eye nematode Thelazia & mechanical vector of bacterium Moraxella bovis (pink eye)
Which pathogens are transmitted by midges?
bluetongue, epizootic hemorrhagic disease (viruses)
What does obligate myiasis mean?
Hosts for larval development must be LIVE
(maggots & bots)
What does facultative myiasis mean?
hosts for larval development can be LIVE or DEAD & larvae can also develop in organic matter
