Review Questions Exam # 3 Flashcards
(124 cards)
1
Q
How can you diagnose neosporosis in cattle? What are your options?
A
◦ Immunological (ELISA) and molecular tests for ruminants
◦ Antibodies in bulk milk
◦ Organism in abortus (CNS, muscle - bradyzoites)
◦ Clinical and epidemiological appearance (abortions mid-gestation)
2
Q
How can you diagnose Eimeria infection in ruminants?
A
◦ Clinical signs/ history - may appear before oocysts are shed. (diarrhea (bloody/ mucous), history of stress, cold snap, dehydration, pale congested mucus membrane, prolapse of rectal membrane
◦ Fecal exam - fecal flotation
3
Q
What is the disease/complex caused by a large number of GI nematodes?
A
◦ Parasitic Gastroenteritis (PGE)
4
Q
Name the surface and burrowing mites commonly found in ruminants.
A
◦ Surface: Chorioptes sp., Psoroptes sp.
◦ Burrowing: Scarcoptes sp., Demodex sp.
5
Q
What are the main clinical signs of haemonchosis in small ruminants?
A
◦ Clinical signs: Anemia in sheep and goat ( both adults and larvae suck blood). Severe clinical disease in sheep goat, camelids, exotic hoofstock ( death). In older cattle it contributes to PGE.
◦ Anemia, submandibular edema (hypoproteinemia)(bottle jaw) death is common.
6
Q
What is the best time to treat for lice?
A
◦ Treat in fall before the louse burdens increase.
7
Q
What is the role of ruminants in the lifecycle of Taenia saginata and Echinococcus granulosus?
A
◦ Ruminants are intermediate hosts for both of these parasites.
8
Q
When you see thick scabby crusts, often having coagulated exudates and intensely pruritic
papules on sheep’s bodies, which mite species might be causing this?
A
◦ Psoroptes
9
Q
Infection of which fluke results in calcified bile ducts or Pipestem liver?
A
◦ Fascicola hepatica
10
Q
Why are cysticercus bovis and hydatid cysts more of a concern to us? What is the role of humans
in the lifecycle of these parasites?
A
◦ Humans are definitive hosts for cysticercus bovis - Humans infected by eating infected meat. Cattle contaminated by ingesting infected human feces/ being in contact with human feces.
◦ Humans are intermediate hosts for hydatid cysts. Larval stage of Echinococcus. All species can get larval stage. Can be fatal for humans ( cysts occur in tissues, if it occurs in liver or heart it can be fatal)
11
Q
What are the slow dividing tissue cysts of systemic apicomplexa called? What are tachyzoites?
A
◦ Bradyzoites are the slow dividing cysts usually found in muscle of IH. Tachyzoites are the fast dividing cysts ( usually those that are spreading from definitive host to intermediate hosts)
12
Q
How do you diagnose Fasciola hepatica infection in cattle?
A
◦ Detection of characteristic eggs in feces,
‣ Large, golden brown, operculated and heavy. Use sedimentation technique, use fluke finder. Also use clinical signs and history
13
Q
What is unique about the lifecycle of Dicrocoelium dendriticum?
A
◦ Peculiar life cycle, land snails and ants intermediate hosts. Fluke hijacks brain of ant and makes them stand on plan without movement waiting to be eaten.
14
Q
How is the lifecycle of protostrongylid lungworms different from general ruminant lungworms?
A
◦ General ruminant lung worms have direct lifecycle, while protostrongylus is an indirect life cycle with Gastropod intermediate hosts.
15
Q
Main clinical signs associated with brain worm infection in ruminants?
A
◦ Clinical signs:
‣ White tail deer: none
‣ Abnormal hosts: ataxia, listlessness, fearlessness, unable to feed/ forage, lameness, weakness, blind/deaf , circling, head tilt/ abnormal neck position, emaciation, paralysis.
16
Q
Advise on which animals to treat for different mite infestations?
A
◦ Choroiptes - contagious among different species.
◦ Demodex - not contagious Treat affected one.
◦ Psoroptes - contagious among one species.
◦ Scarcoptes - Just same species.
17
Q
Are cattle fever ticks one host tick or three-host ticks?
A
◦ 1 host tick
18
Q
On necropsy, where do you expect to find adult Dictyocaulus?
A
◦ Inflammation due to presence of aspirated eggs and larva in bronchioles and alveoli.
19
Q
When (which season) is lice problem more common?
A
◦ common in the winter
20
Q
What is a winter tick? General lifecycle?
A
◦ Dermacentor albipictus - 1 host tick.
◦ Life cycle: Finds host in fall ( larva climb onto plants and wait for hosts to pass by -> larva to nymph on the host ( sept/ november) -> nymph to adult (october to feb) -> adults feed and mate (feb- march)-> The fed and bred female falls to the ground ( march - april) -> Eggs are laid ( june) -> cycle repeats
21
Q
What is the common name for Oesophagostomum?
A
◦ Nodular worm
22
Q
• Name the common chewing and sucking lice of ruminants.
A
◦ Chewing Lice: Damalinia (Bovicola) spp.
◦ Sucking Lice: Haemtopinus spp, Linognathus vituli, Solenoptes capillatus
23
Q
Which protozoa is transmitted sexually in ruminants?
A
◦ Tritrichomonas foetus
24
Q
Know the morphology of Demodex mite
A
◦ Morphology : Elongated with short stumpy legs, cigar looking.
25
Which mite is highly contagious among different species of animals? Which is contagious among
the same species and which is noncontagious?
◦ Choroiptes - contagious among different species.
◦ Demodex - not contagious
◦ Psoroptes - contagious among one species, scarcoptes
26
Modes of transmission of ruminant hookworm?
◦ Transmitted via ingestion of L3 or Percutaneous penetration by L3
27
What is the common name for Haemonchus?
◦ The barber pole worm
28
What is the site of infection of Haemonchus, Ostertagia, Cooperia, Bunostomum, Trichuris, and Oesophagostomum?
◦ Haemonchus: abomasum
◦ Ostertagia: abomasum
◦ Cooperia: Small intestine
◦ Bunostomum: small intestine
◦ Trichuris: large intestine
◦ Oesophagostomum: large intestine
29
re the crypto oocysts shed by cattle immediately infective?
◦ Oocysts shed are immediately infective
30
now the general morphology of the Nematodirus egg. How is it different compared to other
strongyle eggs?
◦ Eggs with smooth thin eggshell. Has two to eight large dark blastomeres separated from the yolk membrane by large fluid filled cavity. Much larger eggs than other trichostrongyles.
31
Besides the small intestine, where can you see Thysanosoma adults? Why is this important?
◦ Can be found in bile and pancreatic ducts. Can block bile ducts and cause digestive disturbances. Also cause an economic loss due to condemnation of livers after slaughter.
32
How can you diagnose Tritrichomonas foetus infection in cows and bulls?
◦ Cows: Microscopy and/or culture of cervical mucous, uterine fluids (aborting cows), Abortus: Stomach fluid
◦ Bulls: - Preputial scrapping (or washes) - Repeated sampling (3 tests at weekly intervals
◦ You can also do culture and PCR or direct PCR ( higher sensitivity than culture alone)
33
What are your two best pieces of advice to control brainworm transmission in domestic
ruminants?
◦ Reduce exposure to gastropods
◦ Deworming during peak transmission months ( late summer, fall) can reduce larval infections.
◦ Fences and other barriers around pasture.
34
Which parasite is commonly referred to as a Ruminant lungworm?
◦ Dictyocaulus Spp
35
Do you need to treat all animals (sheep, goats, horses) on the farm if you detect lice problems in
any one animal/species?
◦ Only treat the same species. Species specific parasite. You must treat the whole herd of the same species thought, since it is highly contagious.
36
What is the common liver fluke of ruminants?
◦ Fasciola hepatica
37
What is the common name for Ostertagia?
◦ Brown stomach worm
38
Which ruminants are most severely affected by giant liver fluke and why?
◦ Sheep the extensive, uninterrupted hepatic migration, without encapsulation, usually fatal, even 1 fluke.
39
What is the spinose ear tick? How is it different from the Asian longhorn tick?
◦ It is a soft tick ( asian long horn tick is a hard tick) It is also a 1 host tick ( asian longhorn tick is 3 host tick) Spinose ear ticks also have just larva and nymphs parasitic and adults are free living, asian longhorn ticks are parasitic at each life stage.
40
Do Demodex mites transmit between animals? Do they cause severe itching?
◦ No it does not transmit. No pruritis is absent
41
What is the predilection site for Tritrichomonas foetus in cows and bulls?
◦ Bulls: Protozoa hides within the crypts of the prepuce ( deeper in older bulls)
◦ Cows: Vaginal mucosa
42
What is the shed/diagnostic stage of Dictyocaulus? Which test do you use to diagnose?
◦ Shed: L1!! L1-L3 in the environment
◦ Diagnostic Stage: L1
- Infective L3
◦ Test: baerman
43
What is the general pathophysiology of ostertagiasis in ruminants? What happens in the abomasal glands, and what is the result?
◦ Developing larvae produces small nodules on abomasa surface. ( larvae is developing within the gastric glands) Significant effect when parasite emerge from gastric glands ( they destroy the gastric glands, disrupt acid base balance, causes inflammation, ect)
‣ Normal Gastric Gland:
• Zygomen glands (on bottom) produce pepsinogen.
• Parietal glands secrete HCl. HCl will convert Pepsinogen to pepsin to break down food.
• No gaps between gland epithelium.
‣ Damaged Gastric Gland:
• Widening of gaps between cells cause hypoproteinemia from protein leaking into gut lumen from the plasma.
• Damaged epithelial cells are replaced by undifferentiated cells, so pepsinogen has nothing to convert it.
• Pepsinogen will leak into plasma ( since there is larger gaps) and pepsin is not produced/ produced very mildly. This causes the gastric pH to increase.
• Increased in pH / lack of pepsin will disrupt the digestive function of the abomasum (malnutrition) and overall there is less availability of nutrients to the animal.
◦ ◦ In a nut shell:
◦ ‣ PH increases, less breakdown of food + diarrhea
◦ ‣ High pepsinogen in plasma
◦ ‣ distention/ widening of gland.
44
What are the main risk factors for Strongyloidiasis in cattle?
◦ High environmental temperature, humidity. Larval develops within a day which allows for continuous transmission (hyperinfection) Sawdust is common in all outbreaks.
45
Which protozoal species are the most important cause of abortions in large ruminants and small
ruminants?
◦ Neospora caninum - dairy cattle
◦ Toxoplasma gondii - sheep and goats
46
What are the roles of deer, cattle, and sheep in the epidemiology of giant liver fluke?
◦ Cattle and moose are dead end hosts : flukes walled off in liver parenchyma, no eggs are shed, no clinical signs, diagnosed at slaughter house typically.
◦ Sheep, Goat, camelids: Also dead end hosts, but have more severe damage.
‣ Sheep the extensive, uninterrupted hepatic migration, without encapsulation, usually fatal, even 1 fluke.
47
Which is the most important parasite of stocker cattle in the US?
◦ Cooperia spp.
48
Explain the general lifecycle of brainworm and the role of white-tailed deer and other ruminants
in the lifecycle.
◦ White tail dear ingests slugs and causes larva to develop into adults, lifecycle complete and repeats.
‣ If other hosts ingest slugs, L3 released in intestines, L3 digestive tract. Travels along spinal nerves/ spinal cord to brain. Causes severe neuro disease. In non natural hosts, larvae does not develop into adults, hence no larval shed in feces.
‣ White tail deer maintains lifecycle, no signs
49
Which nematode species can cause cyst-like structures at the bases of hair follicles, especially in
the ventral midline and on the flanks, udder, teats, face, and neck? How is this parasite transmitted to another host?
◦ Parasite: Stephanofilaria
◦ Fly ingests Microfilaria from dermis of infected animal -\> in fly develops to L3, introduced L3 develop into adults in hair follicles.
50
What are some measures to control/manage flies and maggots caused by the flies?
◦ Site selection for grazing vs manure piles, eliminate arthropod breeding sites (water), larvalcidal treatments of environment (chemical and biological).
◦ You can also use topical repellents/ insecticides, wound care to prevent myiasis, time dehorning, castration, ect for cooler times of years when flies are less active.
51
In which conditions Ostertagia may undergo hypobiosis?
◦ L4 arrest if the host is more immune. This is a strategy to combat immune resistance. They overwinter in arid regions to survive hot dry season.
52
Which species of cryptosporidium that calves have can be transmitted to humans?
◦ C. parvum
53
Which tick species are also called Cattle fever ticks? Where are they found more commonly?
◦ Boophilid Ticks ( Rhipicephalus)- Found more commonly south of Texas along Rio Grande, Endemic in Mexico
54
Why is control of giant liver fluke difficult?
◦ Control is difficult because it has a wildlife reservoir.
55
Which fly species can cause big gaping wounds exposing the bones?
◦ Cochliomyia hominivoraz
56
What is the main clinical sign of Dictyocaulus infection?
◦ Intermittent coughing - “husk”
57
How can you diagnose larval tapeworms in ruminants?
◦ Mostly diagnosed during necropsy/ during meat inspection.
58
Which assemblages of giardia can Ruminants maintain? Can they give giardia to humans?
◦ Mainly assemblage E, and yes to human transmission - zoonotic infections ( source of assemblage A and B)
59
What parasite may be shared among cattle, horses, and pigs?
◦ Trichostrogylus axei
60
What pathological changes does Oesophagostomum produce in the large intestine mucosa?
◦ Causes nodules in mucosa, primary pathology. Inflammation.
61
How is the general trichostrongyle lifecycle – outside and inside the host?
◦ Eggs hatch L1 (L1 freeliving in environment) -\> L1-L3 in the environment within 1 week -\> L3 is infective at this stage -\> Once ingested L3 migrates to the gut and burrow -\> mature into L4 and L5 in GI mucosa before emerging and maturing as adult -\> mating/ reproduction of adult worms -\> female lays eggs which pass out in feces -\> new host ingests L3
62
Adults of which species of tapeworms can be found in the intestine of ruminants?
◦ Moneizia
◦ Thysanosome
63
What are the pathophysiology and key clinical signs of cryptosporidiosis in calves? What age?
◦ Clinical Signs: Mostly subclinical. Debilitating diarrhea in calves within the first 3 weeks of life .Mild diarrhea in older cattle – due to C. andersoni. Life threatening infection in immunocompromised (Autoinfection/hyperinfection)
◦ Pathophysiology: Pathogen causes direct damage to villi ( causing small intestine villus atrophy and dysfunction) Indirect damage ( inflammation, increased permeability, loss of fluid into gut lumen, dehydration.
64
Which parasite of Sheep causes pathology like Ostertagia in cattle?
◦ Teladorsagia spp.
65
What are the intermediate hosts for ruminant tapeworms?
◦ Intermediate hosts: Arthropod
66
What hosts can be infected with Haemonchus placei and Haemonchus contortus?
◦ Haemonchus placei - cattle
◦ Haemonchus contortus - sheep, goats, cattle, exotic ruminants, deer. ( most important parasite in sheep and goats.)
67
If you find microfilaria in the blood of ruminants, which species could it be?
◦ Setaria Spp
68
How can we control/prevent neosporosis infection in ruminants?
◦ Do not allow dogs to eat abortuses, dead cattle, or raw meat
◦ Keep cattle feed & water away from wild canids and dogs
◦ Do not breed seropositive cattle (cull)
◦ No drug therapy is available
69
How common are Psoroptes in cattle in the US?
◦ Rare in dairy cattle
70
What is the main clinical significance of Tritrichomonas in cows?
◦ Infected cows - early embryonic death in first few months of gestation – infertility, open cows!
71
Which is a fringed tapeworm?
◦ Thysanosoma actinioides
72
What diagnostic test can you use to diagnose ostertagiasis besides fecal testing?
◦ plasma pesinogen level - reliable in young animals.
73
How and when may animals develop Type I ostertagiosis?
◦ Mostly in calves turned out in spring pasture grazed by cattle/ calves the preceding year. They will ingest overwintered L3 and freshly developed L3.
74
Do you need to cull the infected cows? What about bulls? Why?
◦ You only need to cull infected bulls ( not cows)
◦ Most cows clear infection and cycle again; a few remain as carriers they do not transfer the disease throughout generations so they do not need to be culled.
75
What is the key pathophysiology of coccidiosis in ruminants?
◦ Merogony: (Asexual) Multiplication of sporozoites to merons, keeps occurring and destroying epithelial cells (small intestines)
◦ Gametogony: Sexual reproduction destroying large intestinal cells.
◦ Diarrhea with mucus and or blood, malabsorption, dehydration, ect.
76
How can you diagnose cattle grubs?
◦ Usually detection of L3 on dorsum or at necropsy. Serology can be done during winter to find them prior to damage to hide.
77
Which fluke can transmit even in areas with no water bodies?
◦ Dicrocoelium dendriticum
78
Which parasite has been implicated in dramatic precocious udder enlargement in heifers?
◦ Strongyloides papillosus
79
How can you differentiate Chorioptes mite from Psoroptes mite? Legs and pedicel morphology?
◦ Chorioptes have trumpets on short unjointed stalks while psoroptes has trumpets on long jointed stalk.
80
Name the two species of flies that cause cattle grubs. Where in cattle’s body they overwinter,
and what are the clinical signs/lesions associated with the infection?
◦ Hypoderma bovis ( common cattle grub): Larva overwinters in the epidural fat of spinal cord (can cause stiffness, ataxia, muscle weakness, and hind lumb paralysis if grubs are killed while in this location. clinical signs are hide damage. Significant hide damage can damage backstraps ( loss of high quality meat)
◦ Hypoderma lineatum (Northern cattle grub): Larva overwinters in the sub mucosa of the esophagus. If killed inflammation of esophageal wall, dysphagia, drooling, and bloat with possible death. Also can cause hide damage. Significant hide damage can damage back straps ( loss of high quality meat)
81
Is subclinical disease important for ruminants/production animals?
◦ Subclinical disease is important because their is production loss in terms of decreased milk production, decreased caucus weight/ composition quality, decreased fertility, and treatment costs due to antihelmintic resistance.
82
Cattle ticks are vectors of which protozoa?
◦ Babesia bigmina, B. Bovis, Anaplasma marginale
83
Which stage of sheep ked are found in the environment?
◦ None? Permanent ectoparasites.
84
What are diagnostic tests done for diagnosing PGE in cattle?
◦ Fecal egg counts : McMaster technique- quantitative.
85
What are the main clinical signs associated with PGE? What are the risk factors?
◦ Usually sub clinical but can cause decreased milk production, reduce feed intake & utilization/ growth and production, decreased fertility, protein loss into the gut, blood loss/ anemia , if clinical signs diarrhea and failure to thrive.. and weight loss?
◦ Effects greater in younger animals, poorly fed animals, animals with concurrent disease.
86
What is an Asian longhorn tick? Why are they more significant in the cattle industry?
◦ 3 host tick- small inornate, no eyes, rectangular basis capitula head region, bell shapped.
‣ Cause anemia and kill cattle, also transmits thelleriosis, babesiosis, anaplasmosis
87
What is the key clinical manifestation of Sarcocystis infection in ruminants?
◦ Systemic Disease in Cattle: Zoites throughout the vascular endothelium- Direct destruction vascular endothelial cells and muscle cells.
◦ Myositis (chronic, eosinophilic) – found in PM \*\*\*\* This is the most common
88
Which fly species need running water to breed?
◦ Black flies (simulium)
89
Do ruminants shed oocysts of Neospora, Toxoplasma, and Sarcocystis? How is the infection
transmitted to ruminants and the definitive hosts?
◦ Neospora: Cattle don't shed oocysts, only canids, cattle get infection through ingestion of oocysts or transplacentally to their calves ( tachyzoites). Definitive hosts contract neospora by ingesting tissue with cysts with bradyzoites, or via eating aborted fetus' containing tachyzoites.
◦ Toxoplasma: Cattle do not shed oocysts, spread from cattle through tissue cysts with bradyzoites. Ruminants get the infection when they ingest infected oocysts from the environment (spread by cats).
◦ Sarcocystis: Cattle do not shed oocysts, spread from cattle through sarcocysts in tissues with bradyzoites. Ruminants get the infection when they ingest infected oocysts from the environment (sporocysts with 4 sporozoites).
90
Which mite causes sheep scab?
◦ Psoroptes
91
Lactogenic transmission is significant in which GI nematode of cattle?
◦ Strongyloides papillosus
92
Which species of ruminant nematodes shed first-stage larvae with a dorsal spine?
◦ Muellerius, Protostrongylus
93
What are the risk factors for coccidiosis in ruminants?
◦ Extreme weather changes, Dirty environment, Stress – transportation, nutritional deficiencies, feed changes, weaning, illness, concurrent disease.
94
Which is the most common type of mange in ruminants in the US?
◦ Chorioptes is the most common mange in ruminants in the US
95
Where can you find the bots of Oestrus ovis? What are the clinical signs that indicate infection
with this fly larvae?
◦ Bots are found in the nasal passages and sinuses of sheep and goats. Clinical signs include restless behavior ( like they are in estrus) Nasal discharge, and sneezing.
96
How do black flies cause vascular damage in their host?
◦ Black flies produce salivary toxin that causes vascular damage.
97
Which parasite can be found in the peritoneal and pleural cavity of ruminants?
◦ Setaria spp ( Bovine abdominal filariosis)
98
Name the hookworm of ruminants
◦ Bunostomum spp.
99
What are the risk factors for blowfly strikes in sheep? How can you prevent blow fly strike?
◦ Risk factors: Warm, humid weather, wounds, and wooly (dirty) sheep. You can prevent blowfly strike by frequent exam, in sheep fly strike often affects the region below the anus and between the hind legs, sheering, wound care, manage diarrhea from PGE, use of insecticides, dips sprays, parenteral MLs.
100
What is the infective stage for the Trichostrongyles and other GI nematodes?
◦ L3 is infective
101
What field test is also used to diagnose anemia due to Haemonchus in small ruminants?
◦ FAMACHA card- compares the color of mucus membranes
102
What are pathological changes in the abomasum associated with Ostertagia?
◦ Dilation of gastric gland with ostertagia larvae within, Morocco leather in the abomasa, markedly inflamed abomasal mucosa in severe infection.
103
Which flies breed/develop on cattle feces?
◦ Haematobia irritans (Horn fly) and Musca autumnalis (face fly)
104
What is the shed stage/diagnostic stage of Strongyloides papillosus?
◦ Shed stage: Larvated egg
◦ Diagnostic stage: Larvated Eggs
105
Which mite species cause scabies in ruminants?
◦ Scarcoptes
106
How do you diagnose surface mites and burrowing mites?
◦ Surface Mites: KOH digestion + superficial skin scrapings
◦ Burrowing Mites: Deep skin scraps + Biopsy
107
How can you diagnose giant liver fluke infection in cattle and sheep?
◦ Diagnosis by fecal testing only possible in Definitive host - Larve eggs morphological thy similar to F. Hepatica.
◦ In cattle, sheep cant do fecal test, no egg.
◦ Mostly diagnosed at necropsy and visual examination of liver for parasites. Big fluke, easily seen.
108
Which mite infestation usually begins from the legs and spreads to other areas?
◦ Chorioptes starts in the legs, and then spreads to other areas.
109
Name the Giant liver fluke, Lancet fluke, Zombie ant fluke.
◦ Fascioloides magna, Dicrocoelium dendriticum ( zombie ant or lancet fluke)
110
What is the infective stage of Fasciola hepatica?
◦ Metacercariae
111
How is Setaria spp. transmitted among ruminants?
◦ Through mosquito bite and spread.
112
What is unique about the lifecycle of Nematodirus? Which stage overwinters in the pasture?
◦ Larva develops to L3 within egg shell which makes it more resistant to adverse conditions.
◦ Eggs will overwinter on pasture and hatching is dependent on extrinsic stimuli ( spring thaw)
113
What is the scientific name of Brainworm/Meningeal worm?
◦ Parelaphostrongylus tenuis
114
What is the key sign of Type I ostertagiasis?
◦ Can cause profuse watery diarrhea ( bright green) in calves
115
How is babesiosis transmitted in ruminants? What are the key clinical signs?
◦ Babesia spp. is tick transmitted. Rhipicephalus (Boophilus) spp. ticks, Ixodes Ricinus – B. divergens
◦ Key clinical signs: Causes Bovine Babesiosis aka. Redwater, Tick Fever
‣ Pyrexia (upto 42 C), haemoglobinuria, anemia, icterus and splenomegaly, hepatomegaly, Dark colored urine, Neurologic signs.
116
What is the public health importance of flukes of ruminants? How can we be infected?
◦ Humans must ingest metacercaria from not properly washed watercress in watercress.
◦ Clinical signs: epigastric pain, prolonged fever, enlarged liver, pyrexia, and weight loss.
117
What is unique about the egg morphology of two ruminant tapeworms? Remember the general
morphology.
Unique Morphology:
◦ Monezia: Squared or diamond-shaped, with a pyriform apparatus vs. diamond/ round eggs of other cestodes. You can also see hexacanth larva.
◦ Thysanosoma has eggs that are in packets, and are similar to haemonchus. They have 6-12 eggs inside. No pyriform apparatus but you may see hexacanth larvae
118
What is unique about the shed stage of Sarcocystis? Are they immediately infective to ruminants?
◦ Shed stage of sarcocystis does not have to sporulate, they are immediately infective. yes they are infective to ruminants.
119
The key clinical sign associated with Sarcoptes infection in ruminants?
◦ Intense pruritis, papules develop into crusts, skin thickening, large folds.
120
What are the diagnostic options for brain worm infection in domestic ruminants?
◦ Baerman in white tail deer to find larvae. Confirmatory diagnosis is via necropsy and finding adults in brain/meninges.
◦ In other hosts: Clinical signs, proximity to white tail deer, serological test to come.
121
Know the oocyst morphology for Eimeria. How is it different from the oocysts of coccidia of
small animals?
◦ Unsporulated: Polar cap over micropyle, single unsporulated oocyst
◦ Sporulated: sporocysts with 2 sporozoites each. Polar cap over micropyle.
Elmiria: Has 4 sporocysts, each containing 2 sporozoites, in small animal coccidia it is two sporocysts each containing 4 sporozoites.
122
Which GI nematode of ruminants is most resistant to anthelmintic drugs?
◦ Cooperia spp.
123
Why Cooperia is important, even if not very pathogenic?
◦ This is important because though subclinical it is an important cause of subclinical production loss.
124
Name the common eyeworm of ruminants.
◦ Thelazia spp.
