Cattle Flashcards
What nematodes are located in the bovids abomasum
Haemonchus placei
Ostertagia ostertagi
Trichostrongylus axei
What nematodes are located in bovine SI
Cooperia spp
Nematodrius spp
Bunostomum spp
What nematodes are located in the bovids LI
Oesophagostomum spp
Parasitic gastroenteritis (PGE) is and what does it cause
; generic term for disease caused by nematodes in the GI
Predominantly a disease of young animals
Clinical disease is only the tip of the iceberg
Subclinical disease causes major production loss
Control has dependent on regular use of broad spectrum anthelmintics
Anthelmintic resistance is a growing problem
Economic burden of cattle caused by GI nematodes
Cost of parasitic nematodes to US cattle industry is >2 billion/year
Clinical disease
Subclinical production loss
Incredibly important to the animal pharmaceutical industry
What is the pathogenesis of parasitic gastroenteritis in cattle
Reduced feed and utilisation, growth and production
Increased loss of protein into gut
Blood loss anemia (haemonchosis in sheep)
If clinical effects: diarrhoea and failure to thrive
Who is effected worse with PGE
Effects greater in
Young animals
Poorly fed animals
Animals with concurrent disease
Trichostrongylus life cycel
Most important nematodes in grazing ruminants all small worms (5-10mm long)
Direct life cycle
L3 is infective (hatched from egg)
PPP~ 3 weeks,, translation ~1 week (ideal conditions)
Eggs all look the same (except nematodirus)
What is hypobiosis
a developmental adaptation that allows parasitic nematodes to survive in their host for long periods of time
What cattle nematode performs hypobiosis
Ostertagia/Trichostrongylus will hibernate in the winter inside the stomach
Type I ostertagiasis is and what are the effects
Summer ostertagiasis
Grazing calves
High burdens of larvae in glands
Bright green watery diarrhea
Weight loss
Onset may be gradual
Morbidity is high
Mortality is low
FEC may be high
Type II ostertagiasis is and what are the effects
Winter ostertagiasis
Yearlings
Inhibited larvae emerge at once
Depression, weight loss, anorexia
Hypoalbuminemia and submandibular oedema
Sudden onset
Morbidity is low
Mortality is high
FEC may be 0 or low
trichostrongylus- Cooperia spp is common where and causes what
Common in temperate regions
Contributes to PGE as part of mixed infection
Sometimes the predominant parasite
May see inappetence and reduced weight gains
Generally the dose limiting parasite
Most resistant to GIN in cattle to NA
Where is Cooperia spp located
Cattle small intestine
Where is nematodirus spp located
Cattle small intestine
trichostrongylus- Nematodirus spp is common in what bovids/how do they become infected
Develop to L3 inside egg
Eggs can be overwinter on pasture
Cattle >6 months of age resistant
Can cause acute diarrhoea in calves
Life cycle of strongyloides papillosus
Larvated eggs are in feces
Develop into l1-l3 in environment
L3 can penetrate the skin
or cattle can ingest free living adults
PPP is 10 days
L3 can be located within colostrum
trichuris spp- whipworm life cycle
Direct life cycle- larvated egg infectious
PPP is 4-6 weeks
Parasitic nematodes of ruminants basic epidemiology
Infection thru ingestion of infective stages from pasture
Possible sources of springtime pasture contamination
Overwintered eggs or larvae (esp. Nematodirus) on pasture
Infected cows returning to pasture (even if treated in fall)
Reactivation of hypobiotic larvae from infected adult cows
Peak pasture contamination and transmission: second half of grazing season (as more animals become infected the pasture becomes more contaminated and then more animals become infected)
Outcome of infected largely dependent on immune status
How do you diagnose GI nematodes in cattle
History- age, season, management (pasture systems, beef, dairy)
c/s
- Anorexia
- Diarrhea
- Weight loss
- May have no obvious signs
Fecal examination
- Fecal egg counts on a herd basis (not individual animals)
- Qualitative or quantitative
- Centrifugal best
Fecal culture and molecular approaches
How would you manage GI nematodes in cattle
Treat and quarantine new stock - prevent introduction
Good husbandry; good nutrition and prevent concurrent disease
Pasture management (avoid overgrazing)
How do you give anthelmintics to cattle
Long acting anthelmintics, rumen boluses, residual effects
What are the common strategic treatments for cattle
Give spring (turnout) treatment to head off pasture contamination
Treat young animals in first grazing season 6-8 weeks later
Give fall treatment to get arrested larvae
What is the lungworm in cattle
Dictyocaulus viviparous
Can you see D.viviparus in feces
Yes, they will eventually poop it out
Life cycle of dictyocaulus viviparus in cattle
PPP 3-4 weeks
Transmitted on pasture
First stage larvae in feces matures to L3 in pasture
Translation period is 5 deals in ideal conditions
Grow ideally in wet pastures
Eaten by cow
Tracheal migration to lungs
Signs of Dictyocaulus viviparous in cattle
Can be subclinical
If clinical, usually calves or previously unexposed cows on wet pasture
Coughing (“husk”), dyspnea, sawhorse stance
Bronchopneumonia
Morbidity and mortality can be high
What are the diagnostic tests for Dictyocaulus viviparous in cattle
Post mortem on lung tissue
Fecal examination
How do you control Dictyocaulus viviparous in cattle herds
Vaccine (irradiated L3) used in Europe, given to calves before first turn out
Anthelmintics: given at midpoint of first grazing season
What are common skin nematodes in cattle
Stephanofilaria stilesi
Superfamily filarioidea
What is the lifecycle of Stephanofilaria stilesi in cattle
PPP: 6-8 weeks
L1-3 on horn fly
Hornfly transmits the L3 on the cows stomach
Introduced L3 develop to adults in hair follicles
Microfilariae(L1) in dermis
Transmitted onto hornfly
Development in IH is 3 weeks
Stephanofilaria stilesi is seen where in Canada and how to diagnose
Present in western canada
Diagnosis: microfilariae in skin biopsy
Treatment of Stephanofilaria stilesi for cattle
Anthelmintic to kill the microfilaria and resolve skin lesions within 2-3 weeks
Adult resist tx and may survive for years
What are the intestinal cestodes in cattle and what do they look like
Moniezia benedenia
No restellum or hooks
Wider than long
Intestinal cestodes in cattle and sheep are and what do they look like
Thysanosoma spp
In bile and pancreatic ducts
No rostellum or hooks
Scolex has 4 suckers
Fringes along the segments
Life cycle of Moniezia spp and Thysansoma spp
PPP 6 weeks
Eggs are in feces
these are immediately infective
Free living mite is the IH infected with a cysticercoids
Development in mite IH takes 1-4 months
What are the common liver flukes in cattle
Fasciola hepatica
Fascioloides magna (giant liver fluke)
Dicrocoelium dendriticum
Fasciola hepatica is located where in Canada and what does it look like
Globally the most important trematode of livestock
But rare to non existent in western Canada
Grey-brown leaf shaped fluke primarily in bile ducts
Can infect many species – cattle, sheep, goats, deer, horses, pigs, zoonotic
Infection occurs only when there is suitable aquatic snail habitat
Life cycle of Fasciola hepatica
PPP 10-12 weeks
Eggs in feces mature to miracidium
Miracidium penetrates the skin of snail
Asexual reproduction within IH
Cercariea is produced
Ingest Metacercaria on vegetation
Where is F.hepatica located in the cow
Adult flukes feed in bile ducts
Anemia, hypoalbuminemia, cholangitis
What are the symptoms of F.hepatica
Progressive loss of condition
Emaciation
Pale mm
Submandibular edema
Ascites
Chronic fasciolosis look like what in cattle
Generally subclinical
Reduced growth and fertility problems
How to diagnose F.hepatica
Post mortem- cholangitis, calcified bile ducts–”pipestem” liver
Use a fecal sedimentation to diagnose
Fascioloides magna is common where in canada
Relatively common in western Canada in cervids- deer, elk, caribou
Spill over to domestic livestock
What does F.magna look like in cattle
Cattle (and moose) are dead end hosts
Flukes walled off in liver parenchyma
No eggs shed, no c/s
Diagnosis at packing plant (no eggs in feces)
What deos F.magna do to sheep
Sheep also dead end hosts, but more severe damage- even death
How do you control F.magna
Control is difficult– wildlife reservoir
Life cycle of F.magna
Eggs in cervid feces
Miracidium penetrates skin of snail
Asexual reproduction in IH
Development outside mammalian host is 6-8 weeks
Cercariae
Ingestion of Metacercaria
Dicrocoelium dendriticum look like and are common in
Small fluke which lives in bile ducts
Cattle, sheep, deer, rabbits, gophers (people)
Worldwide
Cypress hills (AB and SK)
Captain higgins or the “crazy ant fluke”
Dicrocoelium dendriticum life cycle
Excreted in cow dung
Cow eats feces
Drills into digestive tract and matures
Cow passes slime balls which contain the L3 larvae
Ants drink these slime balls
Trematode migrates to the ants “brain”
Controls ant
Using the ant during the night to clamp onto blades of grass
Gets eaten by cow
Migrates to liver to finish lifecycle
Diagnosis of Dicrocoelium dendriticum
Sedimentation or high density zinc sulfate flotation
PPP of Dicrocoelium dendriticum
8 weeks
How do you control flukes in cattle
Seldom necessary in western Canada
In problem herds (herd level diagnosis ), prevention
Avoid known contaminated pastures
Avoid spraying liquid manure from the infected herds near water
Prevent livestock access to wetlands (snail habitat), cervid access to pastures
Control involves
Treatment of all exposed ruminants on farm
Surface mites of cattle
Chorioptes sp
Psoroptes sp
Burrowing mites of cattle
Sarcoptes sp
Chorioptes mites are common when
Common in winter in canada
Signs of Chorioptes mites in cattle
Tail, head, escutcheon, coronary bands
Alopecia, oozing, crusting, +/- ulcers
How do you diagnose mites in cattle
Skin scrapings
Deep skin scraping for burrowing mites
Psoroptes are common in cattle where and c/s
Very, very rare in canada
Typically in winter in europe
Severe generalised pruritus
Is cattle sarcoptes zoonotic and is it common
Cattle specific, highly contagious within cattle
Only occasionally observed in canada
What is the main symptoms in cattle with sarcoptyes
Hair loss
Severe pruritus
Thickened skin
What are the hard ticks common on cattle
Dermacentor variabilis (american dog tick)
Dermacentor andersoni (rocky mountain wood tick)
Dermacentor albipiticus (moose tick)
Dermacentor variabilis (american dog tick) is seen when in cattle
3 host
Sk and east
Adult on cattle in may-june
Dermacentor andersoni (rocky mountain wood tick) is seen when and where in cattle
3 host
West of sk mainly BC
Adults on cattle in spring
Dermacentor andersoni (rocky mountain wood tick) causes what in cattle
Toxin from adult females associated with tick paralysis
Transmits anaplasma marginale among cattle
Dermacentor albipiticus (moose tick) is common where and when
1 host
Anywhere you have cervids
Especially moose
All stages on one host
Seen on cow Fed-march
Adults lay eggs in March-april
Nymph on cattle in Sept-nov
how do you diagnose ticks in cattle
Direct observation/clinical appearance/season of the year
Easily identify to genus level (be on the lookout for invasives!)
How do you treat and control ticks on cattle
Generally not managed (unless paralysis)
Management: fence cervids out, don’t graze known tick habitat in spring (D. andersoni) or fall (D.albipictus)
What is he chewing lice of cattle
Damalinia (bovicola) bovis
What are cattle sucking lice
Haematopinus eurysternus
Linognathus vituli
Solenopotes capillatus
How do you diagnose lice on cattle
History and clinical appearance
Finding lice and nits
Most commonly seen in the winter
Often asymptomatic (carriers)
Hair loss, irritation, pruritus, anemia
Nits on base of hair, recovery and id of adult lice
Treatment of lice for cattle
Variety of drugs available
Chewing and sucking lice
Residual effects often mean retreatment not necessary
Highly contagious (treat all in herd)
What are flies common on cattle
Bot flies (obligate myiasis flies)
Hypoderma bovis, H.lineatum (warbles, cattle grubs)
Basic life cycle of bot flies
adults in environment
eggs on host
larvae in host
pupae in environment
life cycle complete in approx 1 year
Life cycle of hypoderma bovis
L3 in environment
Pupae in environment picked up by fly
eggs on cattle hairs
l1 in skin
migrate through wall of esophagus
l1-l3 grow in cattles back
L3 exits through skin in spring
Diagnosis and control of Hypoderma bovis and H.lineatum
Diagnosis– detection of L3 on dorsum or at necropsy– serology during winter (and only rarely seen theses days because of highly effective treatments)
Targeted systematic treatment (whole herd) in fall with ML
Legislated control programs and effective treatments have reduced the occurrence of hypoderma spp. In western canada and elsewhere in the world
If vigilance is relaxed or less efficacious products are used these parasites would once again become an issue
Blood feeding flies on cattle
Simulium spp. (black fly)
Haematobia irritans (horn fly)
Secretion feeding flies of cattle are
Musca autumnalis (face fly)
Simulium spp. Blackfly life cycle
Adults mate
Females lay eggs in fast flowing water
Larvae hatch and attach to rock and vegetation
Larvae pupate
Pupae hatch to release adult flies, which float to surface in an air bubble
Blood feed (adult females)
Pathogenesis and control of Simulium
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 canada for black fly control
Biological larvicides (e.g., Bacillus thuringiensis israelensis – Bti) or their toxins
Pathogenesis of biting flies in cattle
Harassment (common)
Anemia (rare)
dermatitis/local infection
Hypersensitivity
Pathogen transmission
Control of biting flies in cattle
Management
Site selection for grazing vs manure piles
Eliminate arthropod breeding sites (water)
Larvicidal treatments of environment (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 myiasis
Flagellates protozoa of cattle
Tritrichomonas foetus
Trophozoites
No free living or cyst stage
Cattle and cat strains differ genetically
Transmission Trichomonas foetus
The parasite lives in the genital mucosa
Sexually transmitted
Mostly natural service (pastured animals, but survives AI)
What do you do with bulls infected with trichomonas foetus
Asymptomatic carriers (primary reservoir in herd)
Infected for life- crypts of the purpose epithelium (therefore culled +ve)
What do you do with cows infected with trichomonas foetus and what does it look like
Early embryo death in the first few months of gestation
Most clear infection and cycle again; some may stay infected and remain carriers
Reinfection is possible
Diagnosis of Tritrichomonas foetus in cattle
Epidemiological clues: 50-80% open cows in newly infected herds
Gradual lengthening of the calving interval (age spread of calves)
Cows: organism seen in cervical mucous, uterine fluids from aborting cows
Abortus: organism can be observed in stomach fluid
Bulls
-Preputial scrapings (or washes)
-Repeated sampling (3 tests at weekly intervals)
Culture and PCR or direct PCR
Why is a PCR better to do for trichomonas foetus
-Higher sensitivity than culter alone
Higher specificity: differentiates from other trichomonads, rumen contaminants and free living organisms
Do not freeze samples
Control of Tritrichomonas foetus in cattle
Test and quarantine new animals to herd
Make sure cows are successfully calved last season
Test an cull bulls (no treatment once infected)
Use only young bulls (<4 years old) on pastures, or use AI from reliable sources
Cows: do not breed for at least 3 months, or cull (carriers?)
No effective treatment or vaccine
Annually notifiable to OIE, provincially notifiable in AB
Giardia is how common in cattle and c/s
30% prevalence in calves
Often asymptomatic, can cause acute, intermittent, or chronic diarrhoea
How to diagnose giardia in cattle
Daily fecal samples over 3 days
Direct smear, zinc sulphate flotation, fecal antigen/PCR
How do we manage giardia in cattle
Fenbendazole (10-20 mg/kg per os for 3d)
Address contaminated environment
Apicomplexa is and common in
Intestinal, direct life cycle
- Eimeria spp– coccidiosis
- Cryptosporidium
Tissue cyst forming, indirect life cycle
- Sarcocystis
- Neospora
Life cycle: Emiria species
Unsporulated oocysts in feces
Sporulation in enviro
Sporulated oocysts with 8 sporozoites in 4 sporocysts are eaten
Merogony and gametogony in enterocytes
PPP 2-3 weeks
Eimeria spp causes what in cattle
Coccidiosis
12 species found in cattle
Infection is much more common than diseases
2 clinical syndromes
Ordinary, winter/nervous
What are the significant species of Eimeria spp
Only 2 significant species
Eimeria zuernii
E.bovis
“Ordinary” coccidiosis in cattle is
Probably infected from cows, who excrete oocysts around calving
Young animals (2-6 mos) any time of year
Most common when other stressors are present– crowding, weaning etc.
Severity linked to intensity (can be really high numbers of oocytes)
High morbidity, low mortality
Reasonably good immunity develops
Clinical signs of ordinary coccidiosis in cattle is
Diarrhea +/- blood
Tenesmus
Dehydration
Weakness
Loss of appetite and condition
Winter and nervous coccidiosis in cattle is
Associated with a stretch of extreme cold weather or cold snap
Often other stressors; weaning, shift from pasture to feedlot, transport, crowding
Often no oocysts in feces
Clinica signs as per usual, but more severe
Nervous signs (eg, muscular tremors, hyperesthesia, convulsions with ventroflexion of the head and neck, nystagmus) associated with high mortality rate (80-90%)
How to diagnose coccidiosis
Clinical appearance
Number of oocysts (size and shape for species) in fecal flotation
How to control coccidiosis in cattle
Spread via fecal contamination of feed, water, coats, fomites
Isolate calves with diarrhea if possible
Treatment– all exposed calves, ideally as early as possible
Toltrazuril, ponazuril (coccidiocidal)
Supportive therapy
Prevention: ionophores in feed
Cryptosporidium species have what type of life cycel
Intestinal coccidia
Direct life cycle
What is the life cycle of cryptosporidium
PPP 4-6 days
Shed for 1-2 weeks
Oocytes immediately infective when they leave the host
Pathogenesis of Cryptosporidium spp
Calves <3 mos old most commonly infected
Important cause of neonatal diarrhoea
Millions of oocysts/g of feces
Oocysts immediately infective, highly resist and viable for months in water
Malabsorptive diarrhea, yellow pasty and profuse
+/- anorexia, dehydration, acidosis, fever, depression; can be fatal;
Concurrent infections common – rotavirus, coronavirus, E.coli
Diagnosis of Cryptosporidium in calves
Multiple fecal samples
3 samples over 2-3 day intervals
Diagnostic test options
Fecal flotation (tiny and pink)
Acid fast staining (histopathology, fecal smear)
Immunofluorescence assay (IFA)(cyst antigen)- test of choice to order from diagnosis lab
How to control cryptosporidium in calves
Zoonotic risk from calves to people (and vice versa)
Sanitation: steam clean, desiccation, disinfectants (cresols, phenols, sodium hypochlorite)
Supportive care (hydration, ensure colostrum)
Neospora caninum have what type of life cycle
Tissue cysts
ID life cycle
Outcomes of Neospora infection in pregnant cattle
Abortion or stillbirth (generally mid gestation)
Or infected but clinically normal calf (infection in 3rd trimester)
Or infected calf with neurological signs (2-7 months of gestation)
Underweight and unable to stand, flexed or hyper-extended limbs, lack of coordination, decreased reflexes and sensory perception
Or uninfected calf (rare)
Neospora may also have any of these effects in subsequent pregnancies
Diagnosis of Neospora in cattle
Clinical and epidemiological appearance (abortions)
Serology: ELISA titres in aborting vs non aborting cows
Abortus (CNS, muscle): histology and IHC; PCR
What is the control of neospora in cattle
Do not allow dogs to eat aborted fetus, dead cattle, or raw meat
Keep cattle feed and water away from wild canids and dogs
Do not breed seropositive cattle (cull)
