2020, Iss1 Ruminant Parasitology Flashcards
1
Q
Ectoparasites of Cattle
where to haemotobia irritans (Horn flies) tend to congregate on cattle?
A
back and shoulders or underbelly during heat of the day
2
Q
Ectoparasites of Cattle
When is treatment warranted for Haemotobia irritans (horn flies)?
A
When fly counts per animal exceed 200
3
Q
Ectoparasites of Cattle
Besides irritation leading to production losses, what are the consequences of Horn fly infestations?
A
-mechanical vectors of bacteria causing bovine mastitis
-intermediate hosts of spirurid nematodes causing bleeding sores from stephanofilariasis
4
Q
Ectoparasites of Cattle
Treatment options for horn flies (haemotobia irritans)
A
-insecticide resistance
-cattle-feed additives containing larvacides & insect growth regulators
5
Q
Ectoparasites of Cattle
Where do stable flies (stomoxys calcitrans) feed on cattle?
A
Tend to feed on the legs of cattle
6
Q
Ectoparasites of Cattle
what is the threshold for treatment of stable flies (stomoxys calcitrans)?
A
5 flies per front leg
7
Q
Ectoparasites of Cattle
What are good preventative measures for stable fly (stomoxys calcitrans) infestations?
A
sanitation in and around cattle-raising areas prevents fly population growth locally
8
Q
Ectoparasites of Cattle
The face fly (musca autumnalis) is feeds on what?
A
secretions form eyes and nostrils
sanguineous fluid from wounds around the face
**when feeding their mouth parts can create superficial skin lesions & ocular irritation & damage
9
Q
Ectoparasites of Cattle
What is the threshold for treatment of face flies (Musca autumnalis)?
A
20 or more flies on the face
10
Q
Ectoparasites of Cattle
What is the mechanical vector for Moraxella bovis?
A
face fly (Musca autumnalis)
11
Q
Ectoparasites of Cattle
What is the intermediate host for Thelazia eye worms?
A
face fly (Musca autumnalis)
12
Q
Ectoparasites of Cattle
Where are black flies found?
A
Flowing water
**where larvae develop
13
Q
Ectoparasites of Cattle
What are vectors of vesicular stomatitis?
A
black flies
14
Q
Ectoparasites of Cattle
What can occurs with swarms of black flies?
A
**significant blood loss – simuliotoxicosis
**d/t bioactive salivary factors at feeding sites assoc with persistent biting by swarms
15
Q
Ectoparasites of Cattle
What are examples of diseases that are spread by Culicoides spp?
A
bluetongue
epizootic hemorrhagic disease
vesicular stomatitis
16
Q
Ectoparasites of Cattle
Tsetse flies are of economic importance as ectoparasites because they spread:
A
Trypanosoma spp.
**in africa
17
Q
Ectoparasites of Cattle
myiasis (infestation of maggots) is caused by several fly species, but primarily
A
Superfamilies muscoidea & osteroidea
caliphoridae (blow flies) and Sarchophagidae (flesh flies)– most damaging to cattle
18
Q
Ectoparasites of Cattle
Myiases of One Health importance and are considered reportable by the WHO:
A
-New World Screwworm (Cochliomyia hominovorax) & Old World Screwworm (chrysomya bezziana)
19
Q
Ectoparasites of Cattle
Frantic behavior by cattle to avoid female grub flies (Hypoderma bovis) attempting to lay their eggs on them is known as
A
gadding
20
Q
Ectoparasites of Cattle
What is the treatment of Hypoderma bovis flies?
A
macrocyclic lactones
** autumn and spring
**If treated when H lineatum & H bovis grubs cluster along esopahgus & spinal column– dieing grubs can trigger respiratory distress, paralysis, & shock in treated cattle
21
Q
Ectoparasites of Cattle
How to differentiate between biting and sucking lice:
A
sucking lice– narrow, pointed head, hematophagous
biting lice: feed on skin & hair, have a broad head
22
Q
Ectoparasites of Cattle
In what seasons are lice burden the highest?
A
winter & early spring
–make part of treatment regimen before winter
**except for cattle tail louse– more abundant in summer
23
Q
Ectoparasites of Cattle
Treatment for sucking lice
A
macrocyclic lactones
24
Q
Ectoparasites of Cattle
Why are additional treatments typically required in the treatment of Lice?
A
macrocyclic lactones are inactive against lice eggs or nits
25
Ectoparasites of Cattle
Which mites are responsible for sarcoptic mange/scabies in cattle?
Sarcoptes scabiei var. bovis-- skin burrowing mite
**zoonotic**
26
Ectoparasites of Cattle
What is a nonburrowing mite that causes exudative dermatitis, alopecia & intense pruritus in calves?
Psoroptes ovis
27
Chorioptes bovis inhabits the surface skin on which areas on cattle?
tail & lower legs
**tail, foot & leg mange
28
Ectoparasites of Cattle
How long can C. bovis survive off the host?
for up to 3 weeks
29
Ectoparasites of Cattle
When do cases of demodectic mange ovvur?
late winter & early spring
30
Ectoparasites of Cattle
What are the diseases listed as notifiable by the WHO for animal health caused by tick-borne pathogens that affect cattle?
Bovine babesiosis
anaplasmosis
theileriosis
heart water
31
Helminth vaccines in Ruminants: from development to application
There are few vaccines available against parasitic helminths of livestock currently on the market, against which parasites?
-Dictyocaulus vivparus in cattle
-Haemonchus contortus in sheep
-tapeworm Echinococcus granulosus in sheep
32
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What are the effects of liver flukes on farmers?
-subclinical costs
-Dec milk yield & fertility
-slower growth rates
-reduced feed conversion
33
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
Environmentally when are fluke eggs killed
-dessicate in dry conditions
-high temperature >30C, viability periods are decreased or when temperatures <-5C
-anaerobic conditions
-severely alkaline or acidic pH (pH<4.2, >9)
34
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What is the intermediate host for flukes?
Lymnaeid snails
--Galba truncatula-- preferred host for F. hepatica
-- miracdium penetrates ody of snail & becomes a sporocyst
35
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What is the infective stage of flukes?
metacercariae
36
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
How long can metacercariae survive on pasture?
Can survive up to 1 year
37
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
Can metacercariae survive in silage?
No, not under anaerobic conditions
38
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
In what species are fluke eggs passed from the host?
Deer
sheep (if live long enough)
**NOT CATTLE**
39
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What are the 2 main forms of disease seen in liver fluke infection?
1. Acute fasciolosis-- d/t migration of juvenile flukes through liver parenchyma
2. Chronic fasciolosis: adult liver flukes int he bile ducts
40
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
Sheep are more suseptible to acute fasciolosis, describe the disease progression
liver damage & blood loss d/t migrating flukes --> anemia, proteinemia, weight loss & death
41
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
When is chronic fasciolosis seen?
4 to 5 months after ingestion of smaller numbers of metacercariae
**associated with adult flukes in the bile ducts
42
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What are the typical clinical signs of chronic fasciolosis?
loss of condition
anemia
submandibular edema
ascites
decreased milk yield
fibrosis
cattle-- calcification of the bile ducts
43
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
Which liver fluke is contained with a pseudocyst and usually do not cause clinical signs
F. magna
44
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
Liver damage caused by flukes has what negative side effects?
Clostridium novyi bacteria to enter & result in infectious necrotic hepatitis (Black Disease)
45
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What type of immune response predominates in infected cattle/sheep?
TH2/regulatory
46
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What diagnostic methods can be used to diagnose liver flukes?
fecal egg count
antibody detection in milk or serum
antigen detection in feces
47
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What is the disadvantage of fecal float for diagnosis of liver fluke infestation?
only patent infections can be diagnosed
48
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
When using commercial enzyme-linked immunosorbent assays, when can antibodies be detected?
Detected from 2 to 4 weeks post infection
49
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
When using the commercial enzyme linked immunosorbent assay to test for liver flukes in dairy cattle in bulk milk tank testing, what does a positive result suggest?
approximately 25% of the herd is seropositive
50
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
What makes the treatment of fasciola hepatica challenging in sheep that more commonly are affected by acute fasciolosis?
There are no available anthelmintics against the immature stages
--> instead of timing treatment 8 weeks after peak snail season; Then treating in the spring to reduce pasture contamination
51
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
When are dairy cattle restricted for treatment of liver flukes?
treatment only possible during the dry period
**doesn't always fall at an ideal time of year
52
The Epidemiology and Control of Liver Flukes in Cattle and Sheep
Which drugs are labeled for the treatment of liver flukes in the United States?
Albendazole
Clorsulon
**fluke life stage treated 10 wk onward
53
Epidemiology and control of GI Nematodes of Cattle in Northern Climates
What are the four genera of trichostrongyles that are most frequently identified in cattle
1. Haemonchus
2. ostertagia
3. Trichostrongylus
4. Cooperia
54
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What are parasitic diseases that are transmitted to ruminants by oocysts shed in feces of a carnivore or omnivore definitive host?
neosporosis
toxoplasmosis
sarcocystosis
55
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What is the major way that neosporosis is transmitted in cattle?
transplacentally
56
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What is the definitive host of neosporosis?
Dogs
57
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Neosporosis is important disease in cattle because it causes
abortion
58
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What is the definitive host of toxoplasmosis?
Cats
59
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Toxoplasmosis causes abortion in what species?
sheep and goats
60
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What are the definitive hosts of sarcocystosis?
dogs
cats
wild preadtors
61
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Are there any effective preventative chemotherapeutics or vaccines available in ruminants against neosporosis, toxoplasmosis and sarcocystosis?
None
62
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Which life stage of Neospora caninum disseminate infection in the intermediate host?
tachyzoites
63
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What is the life stage of Neospora caninum that encysts in tissues?
bradyzoites
64
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
When do a majority of Neospora related abortions occur?
5 to 6 months gestation
**can occur at any age 3m-end gestation
65
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Which cows are more likely abort than not, with N caninum?
cows that have N caninum antibodies (seropositive) are more likely to abort than seronegative cows
66
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What are potential neurologic signs of calves born with Neospora caninum?
-calves <2 months old
-underweight
-unable to rise
-born w/o C/S of dz
-Flexoral/hyperextended limb deformity
-Neuro abnorm: ataxia, dec pateller reflexes, loss of CP
+/- exophthalmia or asymmetrical appearance in eyes
-birth defects: hydrocephalus & narrowing of spinal cord
67
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What is the definitive diagnosis of abortion related to neosporosis require?
histologic examination of fetus
--brain, heart, liver, placenta, body fluids or blood serum
**fetal brain most consistently affected
68
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What is the best way to prevent vertical transmission of Neospora caninum?
-culling of seropositive dams and/or heifer calves from seropositive cows
-embryo transfer from seropositive cows to seronegative cows are some management strategies
**no drugs kill N caninum bradyzoites within tissue shifts
69
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What are the infective stage of toxoplasma gondii?
1. tachyzoites: individually & in groups
2. bradyzoites: in tissue cysts
3. sporozoites: in sporocysts w/in sporulated oocysts
70
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Which life stage of T. gondii are susceptible to anti-coccidial drugs and which ones are not?
Tachyzoites: metabolically active & are susceptible
bradyzoites: not metabolically active & not affected by drugs used against coccidia
71
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Where are cysts of T. gondii most prevalent in the animal?
-muscular and neural tissues
--brain, eye, skeletal & cardiac mm
72
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Oocysts of T. gondii are only formed in which species?
cats
--domestic and wild felids
73
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Sporulation of T. gondii oocysts occurs where?
outside of the host
74
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
How are hosts (felids) of T. gondii become infected?
By ingesting tissues cysts in tissues of infected animals OR sporulated occysts in food or drink OR transplacental transmission fo tachyzoites from mother to fetus
75
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
The pathogenecity of T. gondii is determined by which factors:
1. innate susceptibilty of the host spp
2. parasite virulence
3. Stage that is acquired by the host
76
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
T. gondii infects are most severe clinically in intermediates hosts in what life stage?
Oocyst
77
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Toxoplasmosis is most severe in small ruminants, causing:
-embryonic death & resorption
-fetal death and mummification
-abortion
-stillbirth
-neonatal death
78
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Diagnosis of an acute infection with toxoplasma is indicated by:
4-16 fold increase in antibody titer in the second sample
**ELISA
79
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What are the 5 named species of sarcocystis that infect cattle and their definitive hosts?
Sarcosystis cruzi (canines)
Sarcocystis heydorni (primates)
Sarcocystis hirsuta (felines)
Sarcocystis hominis (primates)
Sarcocystis rommeli (felines)
80
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Sarcocystis: intermediate hosts become infected by ingesting what life stage?
sporocysts in food or water
81
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Sarcocystis the merozoites encyst in which tissues?
striated & cardiac mm
**occasionally CNS
82
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
What are the most pathogenic spp of sarcocystis in ruminants?
S Cruzi: cattle
S. capracanis: goats
S tenella Sheep
**transmitted by felids- nonpathogenic; by canids: pathogenic
83
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Clinical signs of sarcosytosis in ruminants
**seen when shizonts developing in blood vessels (acute infection)
-- 3-4 weeks, large dose sporocysts: fever, anorexia, anemia, emaciation & hair loss (rump & tail of cattle, +/- death in some animals
-abortion in pregnant animals
84
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
Of what species of sarcocystis that infect cattle, which ones are zoonotic?
S. hominis
S. heydorni
85
Neosporosis, Toxoplasmosis, and sarcocystosis in Ruminants: An update
How to differentiate Sarcocystis from neospora and toxoplasma in feces?
sporocysts or occysts of sarcocystis are shed fully sporulated in feces, vs N caninum, T. gondii and cystoisospora spp are shed unsporulated
86
Sustainable approaches to parasite control in ruminant livestock
What is an alternative treatment to anthelmintics in the treatment of Haemonchus contortus?
copper oxide wire
secondary plant compounds (ie condensed tannins)
87
Sustainable approaches to parasite control in ruminant livestock
Is copper sulfate beneficial in prevention of gastrointestinal nematodes?
No b/c of risk of copper toxicity in sheep & goats
88
Sustainable approaches to parasite control in ruminant livestock
What is the risk of administering copper wire particles as an alternative treatment/prevention gastrointestinal nematodes?
Copper toxicity/liver disease
**monitoring AST as indicator of copper tox
89
Sustainable approaches to parasite control in ruminant livestock
List secondary plant compounds with anthelmintic activity
tannins
lactones
alkaloids
saponins
terpines
glycosides
phenolic compounds
90
Sustainable approaches to parasite control in ruminant livestock
What are the risks of using secondary plant compounds with anthelmintic activity against GIN?
-reducing feed intake
-inducing nutritional deficiencies
-triggering neurologic effects
91
Sustainable approaches to parasite control in ruminant livestock
How is nematode trapping fungi used to control gastrointestinal nematodes?
fungi trap & destroy developing parasitic larvae in feces, by producing a variety of trapping structures
92
Sustainable approaches to parasite control in ruminant livestock
Using fungal spp to control GI nematodes, requires what kind of management system?
Daily feeding management system
-- fed for a period of 60-120 days at beginning of grazing season
--during periparturient period to reduce pasture contamination
93
Sustainable approaches to parasite control in ruminant livestock
What are approaches to GI nematode reduction, that farmers that are inexpensive?
-optimal nutrition-- feeding higher protein diets
-genetic selection of resistent/resilient livestock
-rotational grazing with multiple species (horses/cattle, with goats/sheep)
94
Sustainable approaches to parasite control in ruminant livestock
Is there any benefits to feeding diatomaceous earth or herbal products (garlic, papaya, pumpkin seeds, ginger)?
There is no research evidence to support their use
95
Epidemiology and Control of GI Nematodes of cattle in southern climates
What are the 2 goals of controlling gastrointestinal nematodes?
1. controlling economic losses
2. controlling clinical disease
96
Epidemiology and Control of GI Nematodes of cattle in southern climates
When is the greatest infection risk for Ostertagia in southern climates?
fall-Spring
97
Epidemiology and Control of GI Nematodes of cattle in southern climates
In comparison to Ostertagia, which gastrointestinal nematodes are more heat tolerant?
C. punctata
hamonchus spp
98
Epidemiology and Control of GI Nematodes of cattle in southern climates
What kind of weather tends to make Gastrointestinal nematode infestations worse?
Rianfall
99
Epidemiology and Control of GI Nematodes of cattle in southern climates
When type II ostertagiasis occurs, which cattle does it most commonly occur in?
older steers
replacement heifers
bulls
99
100
Epidemiology and Control of GI Nematodes of cattle in southern climates
List some management strategies that decrease larval contamination of pastures
-pasture rest in summer-- must have rain at beginning of rest period
-alternating land use as pasture and crop/hay production
-annual or biannual pasture renovation
-cograzing with alternate, less suitable hosts-- alternate calves with adult dry cows, horses, sheep & goats-- not as suitable b/c H. contortus can infect cattle (esp young)
101
Epidemiology and Control of GI Nematodes of cattle in southern climates
What kind of breed susceptibility exists in cattle to GI nematodes?
Bos indicus breeds may be susceptible to Ostertagia b/c parts of the world where too hot
102
Epidemiology and Control of GI Nematodes of cattle in southern climates
What is the difference in susceptibility to GI nematodes in females vs males?
males are more susceptible than females
103
Epidemiology and Control of GI Nematodes of cattle in southern climates
How are fecal egg counts used in management of livestock herds?
-monitoring patterns for grazing mangaement & fore determining treatment thrsholds rath than assessign infection levesl of dinividual animals
104
Epidemiology and Control of GI Nematodes of cattle in southern climates
Are fecal egg counts a good indication of worm infestation?
No, because parasites such as Ostertagia have low fecundity
105
Epidemiology and Control of GI Nematodes of cattle in southern climates
Parasite refugia can come from what two sources?
1. free-living stages on pasture
2. In animals not treated with anthelmintics
106
Epidemiology and Control of GI Nematodes of cattle in southern climates
When deworming cattle, what re some considerations to minimize anthelmintic resistance?
-use products from 2 to 3 classes concurrently
-follow label directions for storage of products is critical
-dose based on actual weight if possible
107
Epidemiology and Control of GI Nematodes of cattle in southern climates
What are strategies to maintain GI nematode refugia?
avoid deworming all animals before turnout onto clean pastures
--esp critical with macrocyclic lactones & other long-acting products
in cow/calf operations consider only deworming cattle younger than 5 years & allow older cows to serve as refugia
-be aware of special circumstances that may alter this recommendation such as nutritional stress, treatment of liver flukes
108
Epidemiology and Control of GI Nematodes of cattle in southern climates
What is the time frame after deworming for GI nematodes to quarantine before turning out to pasture?
at least 3 days prior to pasture turnout after treatment
109
Epidemiology and Control of GI Nematodes of cattle in southern climates
What is the general recommendation for maintain refugia in cow-calf operations?
leave adult females 4 years of age & older untreated
**to make this recommendation work, requires good nutrition and healthy animals
110
Epidemiology and Control of GI Nematodes of cattle in southern climates
For fecal egg count monitoring, how many samples should be collected from each grazing gorup?
15 to 20 samples
111
Cryptosporidium & Giardia in Ruminants
How are cryptosporidium and Giardia transmitted?
fecal-oral route with direct contact with host or consumption of contaminated water or food with oocysts or cysts
112
Cryptosporidium & Giardia in Ruminants
What is the most common clinical symptom associated with cryptosporidium?
diarrhea
--inappetance, fever, or malabsorption
113
Cryptosporidium & Giardia in Ruminants
What is the infective stage of cryptosporidium?
sporulated oocyst
114
Cryptosporidium & Giardia in Ruminants
In relation to the hosts cells, where does cryptosporidium infect?
-intracellular, but extracytoplasmatic
115
Cryptosporidium & Giardia in Ruminants
What are the factors that contribute to the transmissability of Cryptosporidium?
1. simple fecal-oral transmission route with oocysts excreted fully sporulated and immediately infective to other suitable hosts
2. oocysts can persist in harsh conditions for long periods of time
3. oocysts are resistant to many conventional disinfectants, including chlorine
4. ability of infected hosts to shed very large quantities of oocysts
5. low infectious dose (10-30 oocysts)
116
Cryptosporidium & Giardia in Ruminants
Cryptosporidium infection is reported in what age range of young cattle?
between 1 to 3 weeks of age
117
Cryptosporidium & Giardia in Ruminants
What are the 4 main cryptosporidium spp responsible for infections in cattle:
C. parvum
C. bovis
C. ryanae
C. andersoni
118
Cryptosporidium & Giardia in Ruminants
In what location in the gastrointestinal tract does cryptosporidium infect?
abomasum: C. andersoni
Small intestine: C bovis, C ryanae, C parvum
119
Cryptosporidium & Giardia in Ruminants
Ruminants as a source of which zoonotic cryptosporidium spp?
C. parvum and C ubiquitum
120
Cryptosporidium & Giardia in Ruminants
Cryptosporidium is concentrated in what kind of fecal float solution?
saturated sugar solution
121
Cryptosporidium & Giardia in Ruminants
Cryptosporidium is resistant to many disinfectants, but what are adequate ways to sanitize against Crypto?
-cleaning stalls before introduction of new animals
-heat or chemical disinfection (hydrogen peroxide)
-Sterilization processes using steam
-UV light
122
Cryptosporidium & Giardia in Ruminants
What is the infective stage of Giardia?
cysts
123
Cryptosporidium & Giardia in Ruminants
What are factors that contribute to successful spread of giardiases?
1. large numbers of cysts released into the environment by infected hosts
2. cysts that are immediately infectious after excretion & that remain viable for extended times under right conditions (cool temps & moisture)
3. low infectious dose
124
Cryptosporidium & Giardia in Ruminants
What is the diagnostic for Giardia?
Microscopic examination of feces
**concentration techniques recommended & of several fecal samples (sporadically shed)
125
Cryptosporidium & Giardia in Ruminants
What are management practices that can be used to decrease Giardia cysts in the environment to reduce transmission risk?
-regular cleaning and disinfection
-use of floor surfaces that are easy to clean in barns
-prompt removal of feces from animal housing
-use of single-cow calving areas
-adequate intake of colostrum by neonatal animals to ensure adequate transfer of passive immunity
126
Ruminant Coccidiosis
What are the 3 major phases of the life cycle of Eimeria species?
-First two phases are internal (asexual and sexual replication)-- takes 1 to 3 weeks
-next phase is environmental sporogony (sporulation)
127
Ruminant Coccidiosis
What is the infective stage of coccidia?
sporozoites
--released by the gastric fluid contents
128
Ruminant Coccidiosis
Which life stage of coccidia leaves the host cell, rupturing it?
merozoites
129
Ruminant Coccidiosis
What are the prepatent and patent period of coccidia species?
Variable depending on species:
E bovis: PPP 15-23 days, PP: 5-26 days
E. zuernii: 15-22 days, PP: 2-11 days
130
Ruminant Coccidiosis
Eimeria spp are resistant in the environment, what are factors that capable of affecting oocysts?
-direct exposure to UV light over several hours
-Extreme dryness
-high temperatures over long periods of time (about 39 C)
131
Ruminant Coccidiosis
Is immunity across species of Eimeria protective?
**No, do not cross protect against other species
132
Ruminant Coccidiosis
Acquired immunity is based on primarily on what immune response?
-TH1 (T helper) cellular immune response
133
Ruminant Coccidiosis
Is immunity to coccidiosis complete?
No, immunity is protect against clinical coccidosis and doesn't completely suppress parasite replication on reinfection
134
Ruminant Coccidiosis
What species of Eimeria can cause nervous coccidiosis?
E. bovis & E zuernii
135
Ruminant Coccidiosis
What neurologic signs can be seen with Eimeria infection?
eplipetiform seizures-- opisthotonus & nystagmus
136
Ruminant Coccidiosis
At what time of year, is nervous coccidosis most commonly seeN?
IN winter
137
Ruminant Coccidiosis
Eimeria spp causing nervous coccidiosis pathogenesis?
Unknown
138
What parasite is seen on fecal float?
Coccidia
139
what parasite is seen on fecal float?
coccidia sporocyst/sporozoite
140
Ruminant Coccidiosis
At what level on a McMasters fecal float, are coccidia oocysts considered significant?
500 or more
141
Ruminant Coccidiosis
What are preventative measures to be taken against clinical coccidosis?
Herd management
-hygienic measures
-reducing stress
-timely manure removal
-deep litter usage
-non-crowded pasture
-facilites tha tallow direct natural sunlight-- reduce levels of oocysts
-separation of different age groups
-pasture rotation
-appropriate passive transfer of immunity
142
Ruminant Coccidiosis
What are disinfectants that are effective against coccidia?
bleach
cresols or chlorocresols (not available in US)
143
Ruminant Coccidiosis
List drugs that are coccidiostats:
amprolium
decoquinate
sulfonamides
144
Ruminant Coccidiosis
List drugs that are coccidiocides
-polyether ionophores: monesin, lasalocid, salinomycin
-symmetric triazines: toltazuril & diclazuril
145
Ruminant Coccidiosis
Which medications against coccidia are intended as a single-dose oral application that is highly effective against internal stages of Eimeria that can be used for sucklign calves or lambs
toltrazuril
146
Ruminant Coccidiosis
How long should coccidiostats be used for ?
at least 27 days
**ensure treated animals are under protection, b/c drugs do not kill the parasite stages immediately but inhibit their further development
147
Ruminant Coccidiosis
Rather than treating coccidia infection therapeutically, what is the recommended treatment approach?
Metaphylactic approach
148
Diagnostic methods for detecting internal parasites of livestock
What type of GI nematode egg is this?
Strongyle-type egg
149
Diagnostic methods for detecting internal parasites of livestock
What type of GI nematode egg is this?
Nematodirus sp eggs
150
Diagnostic methods for detecting internal parasites of livestock
What type of GI nematode egg is this?
Strongyloides sp eggs
151
Diagnostic methods for detecting internal parasites of livestock
What type of GI nematode egg is this?
Trichuris sp eggs
152
Diagnostic methods for detecting internal parasites of livestock
What type of GI nematode egg is this?
Capillarid-type egg
153
Diagnostic methods for detecting internal parasites of livestock
What is the coproculture technique used for?
genus or species-level identification of third stage larvae (L3)
154
Diagnostic methods for detecting internal parasites of livestock
What is the method most commonly used to ID lungworm larvae?
Baermann technique
155
Diagnostic methods for detecting internal parasites of livestock
What parasite is pictured?
Giardia sp cysts
156
Diagnostic methods for detecting internal parasites of livestock
What parasite is pictured?
Cryptosporidum parvum oocysts
157
Biology and Epidemiology of GI nematodes in cattle
O. ostertagi has detrimental effects on the abomasum, damaging glandular tissue, specifically what cells?
mucus cells & pepsinogen releasing zymogen cells to be replaced by undifferentiated cells
158
Biology and Epidemiology of GI nematodes in cattle
Describe type 1 O ostertagi disease
damage observed in fSG cattle and a result of ingested third stage large (L3) beginning 2 to 4 weeks earlier
159
Biology and Epidemiology of GI nematodes in cattle
Describe type II O ostertagi disease
occurs in yearling housed after their first grazing season, releated to massive emergency of inhibited stages from teh mucosa
160
Biology and Epidemiology of GI nematodes in small ruminants
In what time period are pastures considered safe (larvae cleared from pastures) and in what climates?
Temperate/cool weather: 6 months
Hot weather: 3 months
161
Biology and Epidemiology of GI nematodes in small ruminants
When does hypobiosis typically occur?
Highest rates occur at times when conditions in the environment are least favorable for development and survival of eggs and larvae
161
Biology and Epidemiology of GI nematodes in small ruminants
What dewormers within the benzimidazole drug class?
albendazole
fenbendazole
161
Biology and Epidemiology of GI nematodes in small ruminants
albendazole is approved for the treatment of what parasite
sheep and goats
liver fluke, fasciola hepatica
161
Biology and Epidemiology of GI nematodes in small ruminants
What is the primary mode of action of benzimdazoles
inhibition of microtubule formation
162
Biology and Epidemiology of GI nematodes in small ruminants
Albendazole is contraindicated for use in small ruminants when?
firs t 30 days of gestation b/c embryotoxic effects in early pregnancy
163
Biology and Epidemiology of GI nematodes in small ruminants
Is fenbendazole approved for goats or sheep?
Goats
164
Biology and Epidemiology of GI nematodes in small ruminants
Mechanism of action of macrocyclic lactones (ivermectin)
interfere with chloride channel neurotransmission
165
Biology and Epidemiology of GI nematodes in small ruminants
What are the two macrocyclic lactones approved for oral use in sheep?
moxidectin
ivermectin
166
Biology and Epidemiology of GI nematodes in small ruminants
What is the mechanism of action of imidazothiazoles & tetrahydropyrimidines)?
nicotonic agonists-- cause nematode paralysis
167
Biology and Epidemiology of GI nematodes in small ruminants
What are the approved nicotinic agonist anthelminitics for use in small ruminants?
levamisole & morantel
**pyrantel-- not approved for use in ruminants
