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Parasite Questions Flashcards

1
Q
  1. Describe the difference between EPA and FDA labeled insecticides in dogs and cats.
A

a. EPA = topical insecticides, off label application is illegal
b. FDA = oral and topicals that go systemic, off label application is allowed with restrictions

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2
Q
  1. What is the drug class and mechanism of action of dinotefuran?
A

a. Third generation neonicotinoid
b. Bind nicotinic receptors in the nerve synapse, causing continuous nerve stimulation and death

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3
Q
  1. Describe the clinical signs of stephanofilariasis in cattle.
A

a. Circumscribed dermatitis along the ventral midline, with adult worms located in the superficial dermis

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4
Q
  1. Which of the following is NOT true about how helminth infestations can protect against food allergy. (Multiple Choice)

a. Helminths induce Treg cell responses
b. Helminths prime for Th2-based, non allergic responses
c. Helminths trigger mucosal barrier thickening and increased IgA production
d. Helminths induce non-specific IgE to saturate IgE binding sites on mast cells

A

c. Helminths trigger mucosal barrier thickening and increased IgA production

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5
Q
  1. Which of the following is true regarding the life-cycle of Otodectes cynotis? (Multiple Choice)
    a. Life cycle lasts 3 weeks and has 4 stages: larva, protonymph, deutonymph and adult
    b. Life cycle lasts 6 weeks and has 4 stages: larva, protonymph, deutonymph and adult
    c. Life cycle lasts 3 weeks and has 3 stages: larva, nymph and adult
    d. Life cycle lasts 6 weeks and has 3 stages: larva, nymph and adult
A

a. Life cycle lasts 3 weeks and has 4 stages: larva, protonymph, deutonymph and adult

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6
Q
  1. True/False – All species of hookworm complete their life cycles via the skin.
A

a. False – Uncinaria stenocephala are poor blood suckers and do not complete their life cycles via skin, unlike Ancylostoma spp.

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7
Q
  1. What are the psoroptic mites in goats? Where are their lesions distributed?
A

a. Psoroptes cuniculi = ear canal
b. P. bovis = pinnae, head, face, pasterns, interdigital area

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8
Q
  1. What are the two structures in this biopsy (yellow and white arrows)?
A

Answer:
a. White arrow = superficial parasite (scabies most likely, Cheyletiella also possible)
b. Yellow arrow = egg

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9
Q
  1. What is the causative agent of chorioptic mange in cattle?
A

a. Chorioptes bovis

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10
Q
  1. What is the mechanism of action and drug class of d-Limonene.
A

a. Class = volatile citrus oil extract
b. MOA = dessicant – removes epicuticular oils

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11
Q
  1. Match the parasite with its name.
    a. Dermanyssus gallinae
    b. Lynxacarus radovskyi
    c. Chiggers (Neotrombicula autumnalis, Eurotrombicula alfreddugesi)
    d. Otodectes cynotis
    e. Pneumonyssoides caninum
    f. Cheyletiella
    g. Sarcoptes scabiei
    h. Notoedres cati
A

Answers: a= 3, 5; b = 9; c = 2; d = 8; e = 6; f = 4; g = 7; h = 1

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12
Q
  1. What is the drug class and mechanism of action of fipronil?
A

a. Class = phenylprazole
b. Antagonize insect GABA receptors which causes flaccid paralysis

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13
Q
  1. What are the three species of hookworms in small animals?
A

a. Ancylostoma braziliense
b. Ancylostoma caninum
c. Uncinaria stenocephala

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14
Q
  1. What environment do poultry mites favor?
A

a. Nests and cracks in cages and poultry houses

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15
Q
  1. You want to treat fleas on a rabbit. What product do you NOT use?
A

a. Fipronil – it is toxic to rabbits

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16
Q
  1. Can you give Amitraz to horses?
A

a. No

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17
Q
  1. A dog presents with crusted, hyperkeratotic footpads. Give 5 differentials for this condition.
A

Answer:
a. Hookworm dermatitis
b. Erythema multiforme
c. Pemphigus foliaceus
d. Ichthyosis
e. Idiopathic or familial paw pad hyperkeratosis
f. Hepatocutaneous syndrome
g. Dermatophytosis
h. Leishmaniosis
i. Zinc responsive dermatosis
j. Pelodera strongyloides infection

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18
Q
  1. What is the etiology of pruritus and ear canal debris with Otodectes cynotis infection?
A

a. Hypersensitivity reaction to the mite antigen, which the patient is exposed to early in the infestation
b. Ear canal epithelium is irritated and fills with cerumen, blood, and mite debris

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19
Q
  1. Where do the lesions of Chorioptic mange occur in cattle and what are these lesions?
A

a. Location = rump, tail, perineum, caudomedial thigh, caudal udder and scrotum
b. Lesions = erythema and papules with scale/crusting, variable pruritus, weight loss, hide damage, reduced milk and meat yields due to stress

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20
Q
  1. What is the mechanism of action of Amitraz? (3)
A

a. Monoamine oxidase inhibitor
b. Prostaglandin synthesis inhibitor
c. Alpha adrenergic agonist

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21
Q
  1. What are two main infections transmitted by Haematobia irritans (horn fly) in cattle?
A

a. Stephanofilariasis
b. Staphylococcus aureus

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22
Q
  1. Describe the clinical signs of hookworm dermatitis in dogs.
A

a. Erythematous interdigital webs and spongy/soft footpads with hyperkeratosis at pad margins
b. Ventrum abdomen, sternum, distal limbs can show red papules that become diffusely erythematous, thickened, and alopecic over time with variable pruritus

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23
Q
  1. What side effects can be seen with amitraz? Name 5. Are any of them reversible and if so, how?
A

a. Transient sedation – reverse with yohimbine or atipamezole
b. Pruritus
c. Bradycardia
d. Hypotension
e. Hyperglycemia
f. Hypothermia

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24
Q
  1. What are the two types of insect growth regulators? Give examples of each.
A

a. Juvenile hormone analogs – control early stages of metabolism/reproduction to block eggs from hatching and larval maturation
i. Example = methoprene, pyriproxyfen

b. Chitin synthesis inhibitors
i. Example = lufenuron

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25
20. What is the drug class and mechanism of action of imidacloprid?
a. Drug class = chloronicotinyl nitroguanidine b. MOA = nicotinic receptor antagonist on post-synaptic neurons, causing flaccid paralysis
26
21. What environment do hookworms favor?
a. Grass and soil of runs and paddocks in the spring/summer in cool climates
27
22. What are the types of lice in goats?
a. Mallophaga = Damalina caprae, D. crassipes, D. limbate (chewing) b. Anoplura = Linognathus stenopsis, L. africanus (sucking)
28
23. What are three ways that ticks can harm their hosts?
a. Bite injuries can lead to secondary infections or myiasis b. Sucking blood c. Transmit viral, protozoal, bacterial, rickettsial disease d. Tick paralysis
29
24. What is the drug class and mechanism of action of metaflumizone?
a. Drug class = semicarbazone insecticide b. MOA = block sodium channels in insects so impulses cannot be conducted, causing decreased activity and flaccid paralysis
30
25. What is the drug class of pyrethrins and their mechanism of action?
a. Drug class = volatile oil extract of chrysanthemum flower b. MOA = block closure of ion gates of sodium channels during repolarization, leading to spontaneous depolarization and hyperactivity paralysis
31
26. Describe the life cycle of Dermanyssus gallinae:
a. Length = 8 days b. Adults lay up to 7 eggs after blood meal c. Eggs hatch to 6-legged nymphs which moult to 8-legged protonymphs within 12 – 36 hours d. Protonymphs moult to deutonymphs 15 – 45 hours after feeding e. Deutonymphs molt to adults 15 – 45 hours after fedding
32
27. What cutaneous parasite are donkeys more susceptible to than horses and what are their clinical signs?
a. Besnoitia bennetti b. Signs = cysts on the skin, nares and sclera +/- skin scaling
33
28. Why can moxidectin be used in dogs with ABCB1 gene mutations?
a. Moxidectin is a poor P-glycoprotein receptor substrate, so it is safer compared to ivermectin
34
29. What parasites can sulfur be used to treat? List four other properties it also has.
a. Parasites = non-follicular mites (Sarcoptes, Notoedres, Cheyletiella, lice) b. Other properties = fungicidal, keratolytic, anti-pruritic, bactericidal
35
30. How long is the life cycle of Cheyletiella? Where do the eggs and the life stages live?
a. Life cycle = 21 days b. Mite lives only on the host and eggs are shed into the environment (attached onto hairs)
36
31. What are the two mechanisms of action of avermectins and milbemycins?
a. Potentiate release and effects of GABA, causing hyperactivity paralysis b. Glutamate-gated chloride channel agonist in parasites, causing chloride influx and flaccid paralysis
37
32. A dog is found to have hyperkeratotic paw pads and hookworm eggs on fecal examination and paw scrapings. What do you expect to find on biopsy?
a. Rare larvae (if present surrounded by neutrophils, eosinophils, and mononuclear cells) with larval migration tracts through the epidermis and neutrophilic/eosinophilic perivascular dermatitis
38
33. Name four parasites that can live in the stratum corneum of large and small domestic species and be visible on biopsy.
a. Psoroptes, Chorioptes, Sarcoptes, Cheyletiella
39
34. What stage of larvae enter the dog’s skin in an Ancylostoma infection?
a. 3rd stage larvae
40
35. What gender of flea is more susceptible to oral products and why?
a. Females – they feed more and so ingest more of the product in the blood
41
36. What can Haemotopinus suis be a vector for? What 2 species can it transmit this disease between?
a. Swinepox – can pass to humans from pigs
42
37. What is the mechanism of action of ivermectin?
a. Activation of Chloride channels, causing chloride influx and flaccid paralysis b. Potentiate release and effects of GABA to cause hyperactivity paralysis
43
38. Why doesn’t ivermectin kill trematodes and cestodes?
a. They lack GABA system and ivermectin is a GABA receptor agonist in its mechanism of kill
44
39. What are 3 reportable parasites in goats?
a. Psoroptes cuniculi and P. bovis b. Screw worms c. S. scabiei var ovis
45
40. What is the mechanism of ivermectin toxicity?
a. Altered function of P-glycoprotein, which limits penetration of some substances through the blood-brain barrier, placenta, testes, and intestines b. The altered gene is a mutation in nt230 of the ABCB1 (MDR1) gene
46
41. Where does selamectin accumulate externally? (3 places)
a. Sebaceous glands, hair follicles, basal epithelium
47
42. What is the mechanism of action and structure of lufenuron?
a. Structure = benzylphenol urea compound b. MOA = inhibit chitin synthesis, which blocks embryogenesis and hatching as a result
48
43. What is the causative agent of Psoroptic mange in cattle?
a. Psoroptes bovis.
49
44. Name two exotic species that cannot receive fipronil due to toxicity.
a. Rabbits b. Upland game birds (pheasant, bobwhite quail, grouse)
50
45. What is the mechanism of action of neonicotinoids? Give an example.
a. MOA = post-synaptic nicotinic acetylcholine receptor agonist, leading to hyperexcitability paralysis b. Nitenpyram (Capstar), Dinotefuran
51
46. Name two types of Argasid (1) and Ixodid (2) ticks that affect horses.
a. Argasid = Otobius megnini, Ornithodorus spp. b. Ixodid = Dermacentor albipictus, Amblyomma americanum
52
47. What are the causative agents of Psoroptic mange in horses?
a. Psoroptes ovis, P. equi, P. natalensis, P. cuniculi
53
48. What is the drug class and mechanism of action of selamectin?
a. Semi-synthetic avermectin b. GABA potentiator (causes hyperexcitability paralysis) and glutamate-gated channel binder (causes flaccid paralysis)
54
49. What is the mechanism of action of Spinosad?
a. Nicotinic acetylcholine receptor agonist, leading to hyperexcitability paralysis
55
50. Why can’t you give spinosad and ivermectin together?
a. Spinosad inhibits P-glycoprotein function, which can lead to increased CSF levels of ivermectin and toxicity
56
51. What is the mechanism of action of isoxazoline antiparasitics?
a. Antagonist for GABA-gated chloride channels (keeps channels closed), blocking inhibitory signals and causing hyperactivity paralysis
57
52. Describe the clinical signs of caprine pediculosis.
a. Dermatologic = alopecia, irritation, papulo-crustous dermatitis, self-excoriation b. Systemic = anemia, weakness, decreased productivity
58
53. Give five signs of ivermectin toxicity in dogs?
a. Mydriasis b. Hypersalivation c. Lethargy d. Ataxia e. Tremors f. Coma
59
54. List three ways that arachnids are distinct from insects anatomically.
a. Lack of wings b. Four pairs of legs c. Fused head and thorax
60
55. Define perionyxis.
a. Inflammation of the epidermis around a nail
61
56. List four ways the ticks are different from mites (anatomy and host).
a. Ticks are larger with hairless or short-haired leathery body b. Exposed armed hypostome (organ lying below the mouth) c. Pair of spiracles near the coxae of the fourth pair of legs d. Not host-specific
62
57. How do you prevent re-infection of a dog with hookworm dermatitis?
a. Clean premises and dry paved runs b. Treat dirt and gravel runs with borax c. Routine anthelmintic treatment of all dogs in kennel
63
58. True/ False – Damalina ovis is host specific.
a. False – it can pass between goats and sheep
64
59. Give four differentials for these lesions in a dog.
Answer: a. Angiostronylosis b. Pemphigus foliaceus c. Leishmaniasis d. Papillomavirus
65
60. A 10 week old kitten being fostered in a household with 2 other adult cats and one dog has been diagnosed with ear mites (Otodectes cynotis). Which animals in the household should be treated? (Multiple Choice) a. Just the kitten b. All cats in the household c. All cats and the dog in the household d. Depends on their level of direct contact with the kitten
c. All cats and the dog in the household
66
61. Give four different characteristics between argasid and ixodid ticks.
a. Argasid = soft, less parasitic, less prolific, infest indoors b. Ixodid = hard, highly parasitic, very prolific, infest open country
67
62. Label each tick Argasid or Ixodid. a. Otobius megnini b. Rhipicephalus sanguineus c. Dermacentor variabilis d. Ixodes scapularis e. Amblyoma maculatum
Answer: a = argasid, b – e = ixodid
68
63. Match the ticks’ common name with species name. a. Otobius megnini 1. Brown dog tick b. Rhipicephalus sanguineous 2. Spinous ear tick c. Amblyoma americanum 3. American dog tick d. Dermacentor variabilis 4. Lone star tick e. Ixodes scapularis 5. Black legged tick
Answer: a = 2, b = 1, c = 4, d = 3, e = 5
69
64. What is the life cycle of the Psoroptes parasite?
a. Adult mites pierce the skin, causing fluids to leak and form crusts to cover the mites b. Mites mate and lay eggs under crusts, then larvae hatches and moves through the crust, molting through two nymph life stages to become an adult again c. Life cycle is completed on the single host
70
65. How do Cheyletiella mites move around the skin and feed?
a. They live in the stratum corneum and move through tunnels of epidermal debris b. Attach to the epidermis and pierce it with claws on either side of the mouth, then feed on fluids
71
66. Know the common solutions used in fecal flotation technique and the recommended fecal sample size.
a. Solutions = Zinc sulfate, Sheather’s solution b. Sample size > 5g
72
67. Give three ways in which Norwegian or Crusted Scabies differs from ordinary scabies in dogs? (clinically)
a. High number of mites in skin scrapings b. Absence or low intensity of pruritus c. Formation of thick parakeratotic crusts all over the body
73
68. How long is the screw worm life cycle?
a. 21 days in warm weather
74
69. List three common side effects of DEET in horses.
a. Sweating b. Irritation c. Local skin exfoliation
75
70. Where can Otodectes cynotis mites live on dogs and cats?
a. External ear canal, rest of head, neck, rump, tail
76
71. Describe four aspects of Argasid tick anatomy.
a. Lack of dorsal plate b. Sexes appear similar c. Capitulum is not visible dorsally d. Spiracles lie in from of third pair of unspurred coxae
77
72. What is the causative agent of Chorioptic mange in the US?
a. Chorioptes ovis/bovis
78
73. Where is Otobius megnini located in the US?
a. Southern and Western US
79
74. What is the causative agent of warbles in goats?
a. Przhevalskiana silenus 3rd stage larvae
80
75. When are chorioptes mites more prevalent in horses seasonally and why?
a. Winter – horses are more frequently stabled closer together, so they have more contact which favors parasite transmission
81
76. Which T-lymphocyte subpopulation is consistent with generalized demodicosis infection? (Multiple Choice) a. Increased overall lymphocytes with lower absolute numbers of CD4+ lymphocytes b. Decreased overall lymphocytes with lower absolute numbers of CD4+ lymphocytes c. Increased overall lymphocytes with increased absolute numbers of CD4+ lymphocytes d. Decreased overall lymphocytes with increased absolute numbers of CD4+ lymphocytes
b. Decreased overall lymphocytes with lower absolute numbers of CD4+ lymphocytes
82
77. Describe 3 side effects of Amitraz in horses.
a. Somnolence and depression b. Ataxia and weakness c. Colonic impaction **Due to alpha agonist effects**
83
78. Give the clinical signs of Psoroptic mange in horses.
a. Can be asymptomatic b. Ear disease – head shaking, ear scratching, head shyness, lop-eared appearance (P. cuniculi) c. Mane/tail disease and truncal dermatitis (P. ovis) d. Nonfollicular papules, crusts, excoriations, alopecia
84
79. What is the most common causative agent of pediculosis in pigs?
a. Haematopinus suis (Anoplura)
85
80. How do you group ticks and what three groups do they fall in?
a. Grouped by number of hosts in the life cycle i. One host ticks = all three instars engorge same host ii. Two host ticks = larvae engorge/molt, then nymph drops to ground and adult seeks a new host iii. Three host ticks = requires a different host for every instar
86
81. Draw the life cycle of Otobius megnini.
Answer: a. Eggs hatch into larvae within days b. Larvae feed on lymph from ear canal immediately and turn into nymphs within 5 – 10 days of feeding c. Nymphs feed for 1 – 7 months, then moult to adults d. Adults live 6 – 12 months and lay eggs
87
82. What one tick can Selamectin be used to prevent or treat?
a. Dermacentor variabilis (American dog tick)
88
83. How long can Dermanyssus gallinae mites survive without food? Which phase doesn’t feed at all?
a. Survive up to 9 months without food b. Nymphs don’t feed at all
89
84. Describe how spinous ear ticks appear as larvae, nymphs, and adults.
a. Larvae = pink/yellow, 0.3cm, spherical, 3 pairs of legs b. Nymph = blue/grey, sharp spines, 4 pairs of legs c. Adults = fiddle shaped, not spiny, non-parasitic
90
85. What is the life cycle of Eurotrombicula alfreddugesi?
a. Adults lay eggs on moist ground b. Eggs hatch into red, six-legged larvae that feed on animals c. Larve drop off animals to become nymphs, then adults
91
86. What clinical signs do you expect to see with spinous ear tick infestation?
a. Acute otitis externa, pain, occasional convulsions +/- loss of blood and lymph
92
87. How does the T-lymphocyte population change after clinical cure from demodicosis? (Multiple Choice) a. There is no change from the time of diagnosis b. CD4+ and CD8+ lymphocytes decrease over the course of treatment and return to normal by clinical cure c. CD4+ and CD8+ lymphocytes increase over the course of treatment and return to normal by clinical cure d. CD4+ lymphocytes increase and return to normal, while CD8+ lymphocytes remain low
c. CD4+ and CD8+ lymphocytes increase over the course of treatment and return to normal by clinical cure
93
88. Label the correct spectrum of action for these common medications to treat cutaneous parasite infestations: a. Imidacloprid b. Fipronil c. Isoxazolines (Afoxolaner, Lotilaner, Sarolaner, fluralaner) d. Dinotefuran e. Spinetoram f. Selamectin g. Deltamethrin h. Lufenuron i. S-methoprene j. Pyriproxyfen k. Amitraz l. Moxidectin 1. Fleas (adult) 2. Fleas (larvae/eggs) 3. Ticks 4. Otodectes cynotis (ear mites) 5. Demodex species 6. Sarcoptes scabiei 7. Chewing lice 8. Mosquitoes 9. Sand flies 10. Cheyletiella 11. Neotrombicula autumnalis (chiggers) 12. Notoedres cati
Answer: a = 1, 2; b = 1, 2, 3, 6, 7, 10, 11; c = 1 – 12; d = 1, 2; e = 1,2; f = 1, 2, 3, 4, 6, 10, 12; g = 1, 2, 3; h = 2; i = 2; j = 2; k = 1, 2, 3, 5, 6; l = 4, 5, 6, 10
94
89. Match the shape of the Cheyletiella species sensory organ on the first pair of legs with its species. a. C. yasguri b. C. blakei c. C. parasitivorax 1. Cone-shaped 2. Globoid 3. Heart-shaped
Answers: a = 3, b = 1, c = 2 yasguri = heart-shaped (dogs) blakei = cone-shaped (cats) parasitivorax = globoid (rabbits)
95
90. In what species is Sarcoptes scabiei infestation a notifiable disease?
a. Horses
96
91. What are three treatment aspects of spinous ear tick treatment?
a. Mechanically remove ticks with forceps b. Spray/dip patient in pyrethroids c. Treat otitis externa d. Oil-based otic treatments can smother ticks
97
92. What are four predisposing factors for Choriopties bovis infestation in horses?
a. Heavy feathering b. Warm, humid climates c. Dark environment d. Overcrowding (especially common in winter)
98
93. Where do the lesions occur from nematode infections of dogs by Pelodera strongyloides?
a. Feet, legs, perineum, lower abdomen and chest, tail
99
94. What are the two parts of an ixodid tick?
a. Scutum (hard, chitinous shell covering dorsal surface) b. Capitulum (visible at the anterior end dorsum)
100
95. True/False – Ixodid ticks can be distinguished by sex.
a. True – they are dissimilar in appearance (sexually dimorphic)
101
96. A horse presents with otitis externa, head shaking, ear rubbing, and a lop-eared appearance. Name two parasites that can be responsible for these signs.
a. Otobius megnini (spinous ear tick) b. Psoroptes mites
102
97. Name five parasites commonly seen on rabbits.
a. Psoroptes cuniculi (ear mite) b. Leporacarus gibbus (fur mite) c. Ctenocephalides felis (flea) d. Cuterebra spp. e. Sarcoptes spp. f. Cheyletiella parasitovorax
103
98. Draw the life cycle of Ixodes ticks.
Answer: a. Eggs hatch in 2 – 7 weeks b. Larvae feed for 3 – 12 weeks, then drop off before molting to nymphs c. Nymphs feed for 3 – 10 days then rest for 17 – 100 days before molting to adults d. Adults live 19 months and lay eggs
104
99. What is the principal animal host of Rhipicephalus sanguineus?
a. Dogs in all four life stages
105
100. What is a Knott’s test and what species can it distinguish?
a. Centrifuge anticoagulated blood and evaluate sediment for microfilaria b. Distinguishes D. immitis, D. repens, and Acanthocheilonema species
106
101. Give three differentials for these lesions in a horse.
Answer: a. Irritant contact dermatitis b. Pastern folliculitis/pyoderma (S. aureus, D. congolensis infection) c. Chorioptic mange d. Early lymphangitis
107
102. List 2 – 3 common avermectin and milbemycins.
a. Avermectins = ivermectin, selamectin, doramectin b. Milbemycins = milbemycin, moxidectin
108
What is the mechanism of action of selamectin and moxidectin? (Multiple Choice) a. Enhancing chloride permeability and enhancing release of gamma amino butyric acid (GABA) at presynaptic neurons, causing paralysis of parasites b. Inhibits GABA- and glutamate-gated chloride channels, causing uncontrolled neuronal activity with resultant paralysis c. Acts as a nicotinic acetylcholine D-alpha receptor agonist, causing involuntary muscle contractions and tremors d. Mimics flea juvenile growth hormone, halting development, and concentrates in female flea ovaries, causing non-viable eggs
a. Enhancing chloride permeability and enhancing release of gamma amino butyric acid (GABA) at presynaptic neurons, causing paralysis of parasites
109
104. Compared with animals who have localized demodicosis or those that are healthy, dogs with generalized demodicosis have lower mRNA for what cytokines? (Multiple Choice) a. IFN-gamma and TNF alpha b. IL-5 and TGF-beta c. IL-10 and IFN-gamma d. TNF alpha and IL-5
a. IFN-gamma and TNF alpha
110
105. What are the types of parasites pictured below and their feeding characteristics?
a. Chewing lice – move rapidly on skin, feed on debris/hair b. Sucking lice – blood feeders, closely attached to host for long periods
111
106. What is the causative agent of Chorioptes in horses and which season is it more prevalent?
a. Chorioptes equi (aka bovis) b. More prevalent in winter
112
107. Describe what Rhipicephalus sanguineus looks like as an adult.
a. Vase-shaped capitulum base b. Elongated spiracles c. Same sized fourth coxae (compared to 1 – 3)
113
108. List five diseases that Rhipicephalus sanguineus can be a vector for.
a. Tularemia (Francisella tularensis) b. Ehrlichia canis c. Babesiosis d. Anaplasmosis e. Tick paralysis f. Rocky Mountain Spotted Fever
114
109. What is the suspected mode of inheritance of juvenile demodicosis? (Multiple Choice) a. Autosomal recessive b. Autosomal dominant c. Multiple methods of inherited susceptibility
a. Autosomal recessive
115
110. What are the principle hosts of Dermacentor variabilis (immature vs adult)?
a. Immature life stages = field mouse or other small rodent b. Adult = dog
116
111. What are three distinguishing characteristics of Dermacentor variabilis anatomy?
a. Large fourth coxae b. Rectangular capitulum base c. Ornate scutum
117
112. Distinguish how Cheyletiella and Louse ova are connected to hairs?
a. Louse eggs are firmly cemented b. Cheyletiella eggs are attached with fine fibrillar strands
118
113. What is the life cycle of the sarcoptic mite?
a. Eggs are laid in tunnels in the stratum corneum, then mature to larva over 2 – 3 days b. Larvae mature to nymph stages over 3 – 4 days c. Nymphs transition through both nymph stages over 4 – 7 days, then reach adult stage (live for 1 – 2 months on animal)
119
114. What are five diseases that Dermacentor variabilis can be a vector for?
a. Rocky Mountain Spotted Fever b. St. Louis encephalitis c. Tularemia (Francisella tularensis) d. Anaplasmosis e. Tick paralysis
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115. Match the vector with the disease. a. Rocky Mountain Spotted Fever b. St. Louis encephalitis c. Anaplasmosis d. Tularemia e. Tick paralysis f. Ehrlichia canis g. Babesiosis 1. R. sanguineus 2. D. variabilis
Answers: a = 1, 2; b = 2; c = 1, 2; d = 1, 2; e = 1, 2; f = 1; g = 1
121
116. What is the (2) etiologies of clinical signs of caprine pediculosis?
a. Irritation from biting and sucking b. Hypersensitivity reaction to antigens in lice saliva
122
117. True/False – The sexually reproductive and attachment stages of Otodectes mites life cycle are the same.
a. False – adults are sexually reproductive but they attach as deutonymphs
123
118. What are the genus and species of sarcoptic mites in dogs and cats?
a. Sarcoptes scabiei (dog) b. Notoedres cati (cat)
124
119. What is the mechanism of tick paralysis and which type of tick (argasid or ixodid) is responsible?
a. Ixodid ticks are responsible b. Ticks produce a protein in salivary glands or in ovaries c. Causes ascending flaccid paralysis, attacking the lower motor neurons of spinal cord/cranial nerves, which is reversible when tick is removed
125
120. What lifestage of Pelodera strongyloides invades the skin of dogs and humans?
a. L3 larval stages
126
121. What are five differentials for this lesion on a horse eyelid?
Answer: a. Habronemiasis b. Squamous cell carcinoma c. Bacterial or fungal granulomas d. Equine sarcoid e. Exuberant granulation tissue
127
122. Match the tick-borne disease with the primary vector. a. Anaplasma phagocytophilum b. Borrelia burgdorferi c. Ehrlichia ewingii/ E. chaffeensis d. Ehrlichia canis e. Babesia canis/conradae f. Rocket mountain spotted fever (Rickettsia) g. Anaplasma platys h. Bartonella 1. Dermacentor variabilis 2. Rhipicephalus sanguineus 3. Ixodes scapularis/I. pacificus 4. Amblyomma americanum
Answer: a = 3, b = 3, c = 4, d = 2, e = 2, f = 1, 2; g = 1, 2; h = 2
128
123. What are the top three clinical signs of fipronil toxicity in rabbits?
a. Seizures b. Anorexia c. Lethargy
129
124. Where are Onchocerca species found around the world?
a. O. gutturosa = N. America, Africa, Australia, Europe b. O. reticulata = Europe and Asia c. O. cervicalis = worldwide
130
125. What are the lesions found in goats with warbles?
a. Numerous SC nodules and cysts with a central pore on the back and flanks
131
126. How do chigger larvae eat?
a. Salivary secretions from the mites contain proteolytic enzymes that help the larvae feed from host tissue fluids
132
127. For which tick (Rhipicephalus or Dermacentor) does it make sense to treat the outdoors primarily, versus treating inside the house with environmental pesticides?
a. Rhipicephalus = indoors b. Dermacentor = outdoors
133
128. Give four differentials for these lesions in a cat.
Answer: a. Demodicosis b. Pemphigus foliaceus c. Self-trauma/barbering due to allergy d. Notoedres infestation
134
129. What are the clinical signs of Dermanyssus gallinae mite infestation in dogs?
a. Erythema and papulocrustous, intensely pruritic eruptions on the back and extremities
135
130. Where do Lynxacarus radovsky mites occur in the world? (3 places)
a. Australia b. Hawaii, Florida, Texas c. Brazil
136
131. How long is the Otodectes cynotis life cycle?
a. 3 weeks
137
132. Which of the following breeds are predisposed to developing generalized demodicosis? (Multiple Choice) a. American Staffordshire terrier, Staffordshire bull terrier, Chinese shar‐pei and French bulldog b. Chinese shar-pei, Dalmatian, West Highland White terrier and Chihuahuas c. American Staffordshire terrier, German Shepherd dog, King Charles Cavalier Spaniel d. French Bulldog, English Bulldog, Pembroke Welsh Corgi and Labrador Retriever
a. American Staffordshire terrier, Staffordshire bull terrier, Chinese shar‐pei and French bulldog
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133. Give 3 differentials for a dog with this lesion and a history of lying outdoors on moist ground regularly.
Answer: a. Strongyloides stercoralis b. Ancylostoma caninum c. Uncinaria stenocephala d. Pelodera strongyloides
139
134. What are four treatment options for Otodectes cynotis infestation?
a. Ivermectin PO b. Selamectin or moxidectin.imidacloprid topical c. Isoxazolines d. Fipronil spot on e. Mineral oil topical in ears (smothers mites)
140
135. Identify which photograph is of a louse egg and which is a Cheyletiella egg.
Answer: a = louse egg, vertical attachment with cementing substance b = Cheyletiella egg, horizontal attachment with fine fibrils
141
136. What clinical signs does Boophilus microplus cause in horses?
a. Hypersensitivity reactions within 30 minutes (papules and wheals)
142
137. Where does Psoroptic mange tend to occur in cattle in the US?
a. Beef cattle on range in Western, SW, and Central states
143
138. Give three parasitic differentials for this presentation in a rabbit.
Answer: a. Leporacarus gibbus b. Cheyletiella parasitovorax c. Sarcoptes scabiei
144
139. Describe outdoor control measures to prevent tick infestation.
a. Cut and burn brush/grass b. Treat area in spring and midsummer with approved pesticides
145
140. What is the drug class and mechanism of action of flumethrin?
a. Synthetic pyrethroid b. Blocks closure of sodium channels during repolarization, causing spontaneous depolarization and hyperactivity paralysis
146
141. Give three characteristics distinguishing mites from ticks.
a. Smaller, no leathery coating b. Hypostome is unarmed c. Mites have spiracles on the fused head/thorax (called the cephalothorax)
147
142. What types of horses are predisposed to chorioptic mange?
a. Draft horses and feathered horses
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143. What are the clinical signs of Culicoides gnat hypersensitivity?
a. Animals that are not hypersensitive may have mild reactions b. Topline and ventrum are commonly affected with painful, pruritic, papules and wheals c. Mane and tail rubbing
149
144. What are the two clinical forms of sarcoptic mange in pigs?
a. Hypersensitivity/allergic form – usually in young pigs i. Papules, crusts, excoriations, hematomas b. Hyperkeratotic or chronic form i. Thick asbestos-like crusts on head, ears, neck, distal legs with moderate to intense pruritus
150
145. What is the life cycle of the Culicoides gnat?
a. Females lay 100 to 200 eggs in the environment, which hatch within 2 – 10 days into larvae b. Larvae moult four times (instar I to IV) c. Fourth larval instars moult to nymphs, which pupate for 2 – 3 days and become adults d. Adults live for 20 days e. Transition from egg to adult takes as little as 15 days under ideal circumstances
151
146. What are predisposed body sites for Chorioptes bovis in horses? What are typical clinical signs?
a. Distal extremities and tail base b. Variable pruritus, erythema, crusts and scales; moist or bleeding dermatitis in more severe cases
152
147. What three demodex species are present in canine demodicosis?
a. D. canis b. D. injai c. D. cornei
153
148. What is the etiology of Norwegian or crusted scabies in dogs?
a. Immunosuppressive disease or medication
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149. What is the mechanism of action of isoxazolines? (Multiple Choice) a. Enhancing chloride permeability and enhancing release of gamma amino butyric acid (GABA) at presynaptic neurons, causing paralysis of parasites b. Inhibits GABA- and glutamate-gated chloride channels, causing uncontrolled neuronal activity with resultant paralysis c. Acts as a nicotinic acetylcholine D-alpha receptor agonist, causing involuntary muscle contractions and tremors d. Mimics flea juvenile growth hormone, halting development, and concentrates in female flea ovaries, causing non-viable eggs
b. Inhibits GABA- and glutamate-gated chloride channels, causing uncontrolled neuronal activity with resultant paralysis
155
150. Match the mite with the photo. a. D. canis b. D. injai c. D. cornei
Answer: a = 3, b = 1, c = 2
156
151. Where are demodex mites located on the dog?
a. Within the hair follicles +/- in the sebaceous glands (D. injai only)
157
152. Where do Pneumonyssoides caninum mites live?
a. Nasal passages and sinuses (nasal mite)
158
153. Where is selamectin secreted after systemic absorption?
a. Sebaceous glands
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154. True/False – Lyxacardus radovsky mites have terminal suckers on all their legs.
a. True
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155. How may helminth infections change the immune response? (2 – 3 ways)
a. Induce T reg cells via secretion of parasite excretory/secretory molecules (including AIP-1 and 2) to induce cytokine upregulation associated with Th2 response and tolerogenic dendritic cell phenotype, augment IL-10 and TGF-beta functions, and suppress inflammation b. Induce B cell class switching to IgE, block IgE binding sites on mast cells to block degranulation c. Induce upregulation of IL-33 (Th2 cytokine) which also induces Treg phenotypes
161
156. Nematodes are found in hair follicles and dermal granulomas on biopsy of papules, crusts, and scaling on the chest of a dog. What other confirmatory tests (2) can be run and how do you treat this infection?
a. Confirmatory tests = skin scrapings for small motile nematode larvae or Baermann technique for contaminated litter b. Treatment = remove pet from environment and treat with lime sulfur or amitraz, replace all bedding and destroy previous bedding
162
157. Match the Onchocerca species with the location the adult inhabits in the horse. a. O. gutturosa b. O. reticulata c. O. cervicalis 1. Flexor tendon and Suspensory ligament of fetlock 2. Lamellar portion of Nuchal ligament 3. Funicular portion of Nuchal ligament
a = 2, b = 1, c = 3 gutturosa = lamellar nuchal ligament reticulata = flexor tendon and suspensory lig cervicalis = funicular nuchal ligament
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158. How is habronemiasis treated in horses? (4 parts)
a. Debulk all massive lesions; cryotherapy may be appropriate for thin lesions b. Ivermectin and moxidectin may be appropriate, 2 doses 21 days apart, but larvae remain in the host after death and so can still cause reactions c. Systemic glucocorticoids can resolve lesions within 1 – 2 weeks d. Topical Tresaderm or Synotic - bandaging over topical treatments
164
159. What do demodex mites eat?
a. Sebum, cells, epidermal debris
165
160. What are three treatment options for Chorioptes mites in horses and the prognosis for mite infestation.
a. Treatment options i. Macrocyclic lactones (ivermectin, doramectin, eprinomectin, moxidectin) ii. Local spray application of fipronil iii. Local applications of pyrethroids, phosphoric acid, carbamates or combinations iv. Washing with 2% lime sulfur v. Clipping of hairs for better contact and treatment efficacy b. Prognosis = Treatment failure and relapses common because mites cannot be completely eradicated
166
161. Give four differentials for these lesions in a horse.
Answer: a. Onchocerciasis (O. cervicalis most likely) b. Dermatophytosis c. Occult sarcoid d. Simulium spp bites e. Cutaneous lymphoma or SLE could be considered
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162. What is the life cycle of the demodex mite?
a. Eggs hatch to 6 legged larvae b. Larve molt to 8 legged nymphs c. Nymphs molt to 8 legged adults
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163. Give five differentials for this horse.
Answers: a. Culicoides hypersensitivity b. Chorioptic mange c. Pediculosis d. Psoroptic mange e. Seborrhea f. Atopic dermatitis or food allergy
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164. True/False – Cattle with Scabies tend to have normal lymph nodes.
a. False – peripheral lymphadenopathy is common
170
165. What environment is necessary for lice survival?
a. Winter is preferred – stop breeding above 30 C and die at 50 C
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166. What are the clinical signs of chorioptic mange in sheep?
a. Erythema and papules with scale, oozing and crusts; intense pruritus mainly affecting non-wooled areas (lower hindlegs, scrotum, udder, teats, rump)
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167. What are five factors predisposing adult dogs to demodicosis?
a. Intact female (may relapse during cycling) b. Age c. Poor nutrition d. Parturition e. Stress f. Endoparasites g. Debilitating or immunosuppressive disease (Cushings, hypothyroid) h. Immune suppressive drugs (Apoquel, steroids)
173
168. True/False – Dogs with IgM or IgA deficiency are predisposed to demodicosis.
a. False – demodicosis involves suppressed T cell function, so deficiency in antibodies is not relevant
174
169. What are the clinical signs and causative agents of cattle grubs?
a. Hypoderma bovis and H. lineatum (flies) b. Larvae cause asymptomatic to painful, SC nodules and cysts
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170. What is the main mechanism of immune failure in demodex overgrowth?
a. Depressed T cell function and increased TGF-beta and IL-10
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171. How does the location in the US of Rocky Mountain Spotted Fever affect its vector?
a. SE = Dermacentor variabilis and D. andersoni b. SW and southern US = Rhipicephalus sanguineus (more recent vector)
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172. How do puppies obtain demodex mites after birth?
a. They are received through nursing by 2 – 3 days old, starting on the muzzle and spreading through the rest of the body
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173. How are these mites attached? What kind of mites are they? What phase of the life cycle is happening?
Answer: a. Otodectes cynotis mites b. Attached from the dorsal posterior suckers on deutonymph to the back legs on the adult c. Phase = deutonymph is attached to male adult prior to ecdysis into its adult form
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174. True/False – The species specificity of C. bovis mites is low.
a. True – it can infect horses, cows, sheep, llamas, goats, alpacas
180
175. True/False – Expect a worsening of signs after Onchocerciasis is treated in horses.
a. True – dead and dying microfilaria cause an inflammatory reaction
181
176. Describe the criteria for localized versus generalized demodicosis.
a. Localized = 1 – 6 small, circumscribed, erythematous, scaly areas of alopecia b. Generalized = 12 or more localized lesions, involvement of an entire body region, or involvement of at least 2 feet
182
177. What is the age cutoff for juvenile onset demodicosis in dogs?
18 months
183
178. Where does localized demodicosis most commonly cause lesions? (2)
Face, forelegs
184
179. What two species of lice are present in horses?
a. Werneckiella equi (chewing lice) b. Haematopinus asini (Sucking lice)
185
180. What do adult Walchia americana mites eat?
a. Collembola insects (spring tails)
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181. What are the zoonotic signs of scabies mites in humans?
a. Intense pruritus and pimple-like skin rash, most often under wrist bands (watches) or around the waist or underneath bra bands, between fingers, or in the inguinal area
187
182. How does the CD4 versus CD8 ratio change in animals with demodicosis?
a. CD4 lymphocytes are reduced while CD8 lymphocytes predominate, leading to a decreased CD4+/CD8+ ratio
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183. Describe characteristics of generalized canine demodicosis infestation.
a. Patches of erythema and alopecia which enlarge over time b. Comedones and folliculitis c. Peripheral lymphadenopathy d. Nodules or plaques in English bulldogs e. Often affects head, legs, and trunk f. Pododermatitis, ceruminous otitis
189
184. In what parts of the USA does Anatrichosomiasis occur?
a. Florida and Arizona
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185. How are Demodex canis mites acquired in dogs?
a. Transmitted from bitch to nursing neonates by direct contact during first 2-3 days of life
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186. What is unique about the presentation of Demodex injai infestation in dogs? What three breeds are commonly affected?
a. Greasy seborrhea and mild hair loss, mainly affecting the face and topline b. Breeds = Westies, Shih tzu, Fox terrier
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187. What are two causative agents of Trombiculiasis in horses?
a. Trombicula alfreddugesi b. T. splendens c. T. autumnalis d. T. sarcina
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188. Identify what parasite is likely found on this biopsy in a horse with crusted, scaly plaques on the face and leukoderma of the muzzle.
Onchocerciasis (likely O. cervicalis)
194
189. Which of the following non-acaricidal topical agents has shown efficacy against Otodectes cynotis? (Multiple Choice) a. Surolan (Prednisolone, Polymyxin B, Miconazole) b. Canaural (Prednisolone, Fusidic acid, framycetin, Nystatin) c. Tresaderm (Dexamethasone, Neomycin, Thiabendazole) d. All of the above
d. All of the above
195
190. What are the clinical signs of cat fur mite infestations?
a. Variable pruritus b. Hairs appear salt and pepper colored and epilate easily to cause patchy alopecia up to exfoliative dermatitis, mainly on the topline
196
191. What are the risk factors for Rocket Mountain Spotted Fever?
a. Hunter and outdoor dogs
197
192. Give five differentials for these lesions in a horse.
Answer: a. Chorioptic mange b. Dermatophilosis or Dermatophytosis c. Insect bite hypersensitivity d. Staphylococcal folliculitis e. Forage mites f. Trombiculiasis g. Poultry mites h. Besnoitiosis
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193. What are the intermediate hosts of different Onchocerca species in horses?
a. O. gutturosa = Simulium and Culicoides spp. b. O. reticulata and O. cervicalis = Culicoides spp.
199
194. What is myiasis?
a. Invasivon of a living vertebrate animal by fly larvae.
200
195. Where do Oxyuris equi (pin worms) live and lay their eggs in horses?
a. Live in the cecum and colon as adults, then female worms crawl out of the anus and lay their eggs on the perineal skin
201
196. What equine parasite contributes to the worsening of chronic progressive lymphedema in horses?
a. Chorioptes bovis mites
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197. Describe a treatment plan for scabies in the environment for dogs and cats.
a. Mites live in the environment for only 2 – 3 days if not on animals b. Wash all bedding and clothing touched for 3 days before starting treatment, then again after starting treatment – wash in hot water/hot dryer or drycleaned c. Clean/vacuum rooms to remove any debris that could serve as fomites d. Environmental disinfection sprays not considered necessary by CDC
203
198. Demodicosis has been associated with an abnormal distribution of lymphocytes. Which answer represents the atypical distribution of lymphocytes seen in dogs with demodicosis? (Multiple Choice) a. Decreased CD3+, CD8+ lymphocytes b. Decreased CD4/CD8 ratio c. Increased CD4/CD8 ratio d. Decreased CD3+, Increased CD8+ ratio
b. Decreased CD4/CD8 ratio (mainly CD4)
204
199. A goat is found to show severe, localized pruritus characterized by unilateral, linear, alopecic ulceration, crusting, and scarring on the shoulder and flank. The patient is also starting to show neurologic abnormalities. Many white tailed deer have been seen in the area. What is the causative sign of this and the etiology of these lesions?
Answers: a. Parelaphostrongylus tenuis b. Larvae migrate and irritate dorsal nerve roots that supply the affected dermatome
205
200. What parasite is likely present in each of these photos?
Answer: a = Scabies, b = Demodex canis or Demodex cati
206
201. True/False – Localized demodicosis tends to heal without treatment.
a. True – spontaneous resolution within 6 – 8 weeks is common
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202. What are the histopathology findings of aberrant skin migration of D. immitis?
a. Angiocentric pyogranulomatous dermatitis, variable eosinophils b. Microfilarial segments IV and extravascularly in granulomatous dermal nodules
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203. Give five differentials for this cat.
Answer: a. Notoedres cati b. Pemphigus foliaceus c. Otodectes cynotis d. Dermatophytosis e. Squamous cell carcinoma/Solar dermatitis
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204. What is the life cycle of the screwworm?
a. Sexual mature flies mate, then gravid female seeks a host b. Female deposits eggs in mass on the side of a wound c. Eggs develop to larvae via 3 larvae stages in the wound d. Larvae drop to the ground (3rd stage larva only), then burrow into soil and pupate e. Young fly emerges from pupa and matures to sexually mature stage
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205. Match the environment of the Trombicula mite in horses with the mite species. a. T. alfreddugesi b. T. splendens c. T. autumnalis d. T. sarcina 1. Forested and swampy areas 2. Europe 3. North and South America 4. Australia 5. Chalky soils, grasslands, and cornfields
Answers: a = 1, 3; b = 1, 3; c = 2, 4, 5; d = 4 alfreddugesi = forest/swampy, N. & S. America splendens = forest/swampy, N. & S. America Autumnalis = Europe, Australia, chalky grassland/cornfield sarcina = Australia
211
206. Describe the clinical signs of anatrichosomiasis in dogs and cats.
a. Necrosis, sloughing, and ulceration of footpads with accompanying lameness
212
207. A cat presents with exfoliative dermatitis and hairs are found to have a salt and pepper appearance. What would your first step in diagnostics be?
a. A trichogram to look for cat fur mites due to the salt and pepper appearance to hairs
213
208. What breed is predisposed to Babesia canis and Ehrlichia canis?
a. Greyhounds and greyhound mixes
214
209. A horse presents with rat tail. What are five parasitic differentials for this condition?
Answers: a. Oxyuris equi b. Insect bite hypersensitivity (Culicoides spp.) c. Pediculosis d. Psoroptic mange e. Chorioptic mange
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210. What is the life cycle of Otodectes cynotis?
a. Eggs are laid within cement that sticks it to the substrate b. Eggs hatch to 6 legged larvae within 4 days, then feed for 3 – 10 days, then rest for 10 – 30 hours before hatching in 8 legged protonymphs c. Protonymphs moult to deutonymphs which attach to the male adult and copulate if a female mite emerges from the deutonymph
216
211. What are the recommended treatments (2) for poultry mite infestation in dogs and cats?
a. Insecticide bath, dip, or spray b. Treat secondary infections c. Freeze/heat environmental objects to -20C or 45C or chemical sanitation
217
212. What is the life cycle of Lynxacarus radovskyi?
a. Adult female lays eggs, which develop into larvae (6 legs) and then moult twice as female nymphs and once as male nymphs b. Nymphs moult to adults, which both cling to hairs on the animal
218
213. How long do you treat generalized demodicosis for?
a. At least 2 negative scrapings, 2 – 4 weeks apart
219
214. What is the only licensed US product to treat demodicosis and what are its licensed dosing instruction?
a. Amitraz b. Dose = 250 ppm application every 14 days
220
215. Describe the life cycle of Trombicula mites in horses. When do they feed on mammals?
a. Lasts 50 – 70 days (2 – 3 months) b. Eggs laid in soil and then hatch in a week c. Larvae attack horses and humans, feed, and then drop off the host to molt to adulthood in the environment
221
216. What side effects can amitraz cause on the humans who are applying it? (3)
a. Asthma attacks b. Contact dermatitis c. Migraine-like headaches d. Hyperglycemia e. Interactions with MAOIs
222
217. What are four drugs you should not give while applying Amitraz dips? Why?
a. Benzodiazepines – alpha adrenergic agonist b. Xylazine - alpha adrenergic agonist c. Selegilene - MAOI d. L-deprenyl - MAOI
223
218. A dog presents with sneezing, excess lacrimation, and facial pruritus. What parasite would you be most concerned about and what are three medications you could use to treat it?
a. Pneumonyssoides caninum (nasal mites) b. Treatment = isoxazolines, ivermectin, milbemycin, selamectin
224
219. What is the dose of ivermectin used to treat scabies versus demodicosis in dogs?
a. Scabies = 0.2 – 0.4 mg/kg daily b. Demodicosis = 0.3 – 0.6 mg/kg daily
225
220. What are the two main species causing Schistosomiasis in small animals? Where are they located in the USA and what are their hosts?
a. Austrobilharzia = ducks/terns in Florida/Hawaii in summer b. Trichobilharzia = waterfowl in great lakes in summer
226
221. What are Culicoides gnats attracted to on horses? (3 compounds)
a. CO2 b. Lactic acid c. Octenol
227
222. Match the location of disease with the type of louse in a horse. a. Werneckiella equi b. Haematopinus asini 1. Head 2. Back 3. Thighs 4. Mane 5. Fetlocks 6. Tail base 7. Neck
Answer: a = 1, 4, 6; b = 1, 2, 3, 5, 7 W. equi - head, mane, tail base H. asini - head, back, thighs, fetlocks, neck
228
223. What breed of dog is predisposed to Babesia gibsoni?
a. Pit bull breeds
229
224. Can selamectin or moxidectin be used to treat Demodex canis mites?
a. No – they are only effective for non-follicular mite infestations
230
225. What is the cause of sarcoptic mange in pigs?
a. Sarcoptes scabiei var. suis
231
226. What are the three species of demodex mites found in cats?
a. D. cati b. D. gatoi c. Additional non-named intermediate Demodex species
232
227. Give 2 differentials for these lesions on a horse’s ventrum.
Answers: a. Haematobia irritans (horn fly) bites, Tabanids b. Culicoides spp. gnat bites
233
228. What is the causative agent of chorioptic mange in camelids?
a. Chorioptes bovis
234
229. Match the demodex species in cats with its photo. a. D. cati b. D. gatoi c. Additional third species
Answer: a = 2, b = 3, c = 1
235
230. Describe how the immune system is hypothesized to control demodex mites on the skin of healthy animals.
Chitin in demodex mites is recognized by TLR2 on keratinocytes to elicit an innate immune response b. Most mammals harbor mites in the hair follicles and sebaceous glands in low numbers
236
231. What is unique about Demodex gatoi infestations?
a. They inhabit the stratum corneum, unlike all other dog/cat demodex species, and are contagious similar to Scabies mites
237
232. True/False – Lynxacarus radovskyi mites are highly contagious.
a. False – infection typically occurs via direct contact or fomite carriers
238
233. What lice are most common in cows?
a. Mallophaga = Damalinia bovis b. Anoplura = Haematopinus eurysternus, Linognathus vituli, Solenopotes capillatus
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234. What disease does Strongyloidosis predispose horses to develop and why?
a. Rhodococcus equi lymphangitis due to penetration of Strongyloides westeri larvae disrupting the skin’s integrity
240
235. Where does Demodex cati most commonly cause disease?
a. Face/head but can be generalized
241
236. What are the 2 most common cat breeds susceptible to generalized demodicosis?
a. Siamese and Burmese
242
237. Describe the clinical signs of Trombiculiasis in horses.
a. Papules and wheals with the chigger at the center of the lesion b. Sneezing and head shaking c. Marked pruritus, cutaneous edema, exudate, crusting, and ulceration (if severe infection)
243
238. What three species of mosquitoes can affect horses?
a. Aedes species b. Anopheles species c. Culex species
244
239. What are the face and foot louse in sheep?
a. Face louse = Linognathus ovillis b. Foot louse = Linognathus pedalis
245
240. Give five ruleouts for this cat.
Answer: allergies (food, atopy), Demodicosis, ear mites, Cheyletiella, fleas, Notoedres, dermatophytosis
246
241. Where does Demodex gatoi most commonly cause disease?
a. Lateral thorax, ventral/lateral abdomen, medial aspects of legs
247
242. What is the causative agent of warbles in cattle?
a. 2nd stage larvae of Hypoderma spp. flies
248
243. What are the 5 common clinical abnormalities of tick-borne diseases?
a. GI upset b. Lethargy c. Arthralgia and myalgia d. Spinal pain e. Neurologic abnormalities f. Vasculitis g. Fever
249
244. What fly species is a vector for Onchocerca cervicalis?
a. Culicoides gnats
250
245. This microfilaria was found on biopsy of a pruritic, papulonodular dermatitis on the limbs and shoulders. Give two differentials.
Answer: a. Dirofilaria immitis b. Dirofilaria repens c. Acanthocheilonema
251
246. Differentiate male and female Otodectes cynotis adult mites.
a. Female mites have a rudimentary fourth pair of legs that males don’t have
252
247. What two types of forage mites cause clinical signs in horses?
a. Acaridae and Pediculoididae species
253
248. Where are Demodex gatoi mites found on biopsy?
a. Stratum corneum
254
249. What is the life cycle of Dracunculus species?
a. Host ingests the intermediate host (usually a Cyclops – microscopic crustacean) containing the larvae b. Larvae develop in the host for 8 – 12 months c. Adult worms move to SC tissue of abdomen and limbs to form a nodule and fistulate d. When the host enters cool water, the female worm releases larvae through the cutaneous fistula
255
250. True/False – A cat diagnosed with D. gatoi infestation lives with 3 other cats, but you don’t need to treat the other cats.
a. False – D. gatoi is contagious, so all cats in the household should be treated
256
251. Differentiate chiggers versus arachnids.
a. Chiggers = 6 legs b. Arachnids = 8 legs
257
252. What species of lice are found on camelids?
a. Mallophaga = Bovicola breviceps b. Anoplura = Microthoracius mazzi, M. camellia
258
253. What is the life cycle of Schisotomiasis?
a. Miracidia are shed in the feces of the host (usually waterfowl) b. Miracidia hatch within 20 minutes and are consumed by a mollusk within 12 hours c. Form sporocysts inside the mollusk and hatch as cercaria within 4 weeks d. Cercaria are shed into water and reach natural host within 24 hours e. Cercaria move to the liver and intestinal wall to lay eggs, which are passed in feces
259
254. What are the clinical signs and causative agent of botflies in horses?
a. Gasterophilariasis (Gasterophilus spp. flies) b. Signs = 1 – 2mm, wide, gray-white, crooked streaks in the skin of cheeks, neck, and shoulders
260
255. What species is responsible for canine scabies infestation?
a. Sarcoptes scabiei var. canis
261
256. What are the clinical signs of Lynxacarus radovskyi in cats, aside from pepper-salt hair?
a. Generalized maculopapular to exfoliative dermatitis
262
257. What is the life cycle of the Sarcoptes mite in dogs?
a. 17 – 21 days long b. Adults copulate in molting pocket on surface of skin c. Fertilized female forms tunnel through stratum corneum and lays eggs d. Eggs hatch to larvae, which burrow through stratum corneum and feed, then rest in molting pocket e. Larvae molt into nymphs, which wander until they molt into adults
263
258. Differentiate S. scabiei from N. cati mites anatomically (3 ways)
a. S. scabiei anus is terminal; N. cati anus is dorsal b. N. cati is smaller with more body striations c. N. cati has shorter anterior legs
264
259. Give five differentials for this cat.
a. Demodex cati b. Notoedres cati c. Dermatophytosis d. Pemphigus foliaceus e. Mosquito bite hypersensitivity f. Otodectes cynotis
265
260. What is the appearance of the adult S. scabiei mite?
a. 200 – 400 microns long b. 2 pairs of short anterior legs with long, unjoined stalks and suckers c. 2 pairs of posterior legs that don’t extend past the body with long bristles extending from the legs and no suckers d. Terminal anus
266
261. What condition are black flies commonly associated with in horses?
a. Aural plaque development (papillomavirus 3 – 6)
267
262. True/False – S. scabiei is species specific.
False
268
263. How long can scabies mites live off the host?
a. 2 – 6 days room temp, up to 3 weeks at lower temp
269
264. Where are the classical lesions of S. scabiei infestation located?
a. Hocks, elbows, pinnal margins
270
265. Divide flies on horses into primary, secondary, and tertiary categories. What does this mean?
a. Primary = initiate a fly strike by laying eggs on a living animal (Phormia regina) b. Secondary = eggs laid on animals that already are struck, extending the injury (Chrysomya, Sarcophaga spp) c. Tertiary = larvae do little further damage and come last (Musca domestica)
271
266. This mite is found on skin scraping of a horse. Describe its expected clinical signs and how you treat it.
Answer: a. Mite = Dermanyssus gallinae b. Clinical signs = pruritic papules and crusts in contact areas +/- topline (especially if above tail) c. Therapy: i. Eradicate mites from premises through bird nest removal and environmental pesticides ii. Treat horses with one time parasiticidal spray/dip
272
267. What is the spectrum of avermectins?
a. Round worms, lungworms, eyeworms b. Sarcoptes scabiei c. Demodicosis d. Sucking lice e. Heartworms
273
268. Give the clinical signs of forage mite dermatitis in horses.
a. Pruritic or non-pruritic papulocrustous dermatoses on skin in contact with food (muzzle, head, neck, ventral thorax, abdomen)
274
269. What are the four common labwork abnormalities of vector borne diseases (CBC/Chem/UA)?
a. Anemia b. Thrombocytopenia c. Hyperglobulinemia d. Proteinuria
275
270. How is Lynxacarus radovskyi treated in dogs and cats (2 ways)?
a. Lime sulfur dip every 7 days b. Ivermectin or imidacloprid/moxidectin
276
271. Which feline demodex mite is contagious?
a. Demodex gatoi
277
272. How fast after exposure to S. scabiei does mite reproduction occur?
a. 6 – 14 days
278
273. Describe the clinical signs of S. scabiei infestation in dogs.
a. Crusted papules, expanding to alopecic, erythematous skin and thick crusting accompanied by severe pruritus on hocks, elbows, pinnal margins
279
274. A dog is diagnosed with S. scabiei infestation. What clinical signs do you warn your owners they may see on themselves?
a. Severe pruritus with papules on the trunk/arms (especially under waistbands and watches) b. Lesions regress spontaneously within 12 – 14 days once infected dog is treated
280
275. What is the pinnal-pedal reflex?
a. Rubbing the pinnal margins induces hindlimb scratching in 50 – 90% dogs positive for S. scabiei infestation
281
276. What stage of Hypoderma infestation is responsible for nodule formation in horses?
a. 3rd stage larvae
282
277. A cocker spaniel presents with flaking and scale on the back with mild pruritus. The cat in the house also has started to develop miliary dermatitis. How do you want to treat this family?
a. Likely Cheyletiella infestation (or fleas) b. Treat with selamectin every 2 weeks, milbemycin weekly for 3 weeks, or fluralaner once to both patients. Treat any other non-symptomatic animals in the house as well.
283
278. A dog is positive for S. scabiei, but you want to test it for environmental allergies. What other allergen can scabies cause to be positive on a skin and ELISA test? How long will this last?
a. Dust mite antigens are often positive on skin/ELISA b. Antibodies last up to 4 months post-treatment, but seroconverstion takes 5 weeks
284
279. What parasite is responsible for cat scabies?
a. Notoedres cati
285
280. How many legs do Demodex canis mites have as larvae, nymphs, and adults?
a. Larvae = 3 pairs b. Nymph/Adult = 4 pairs
286
281. What are the clinical signs of aberrant skin migration of Dirofilaria immitis in dogs and cats?
a. Dog = chronic pruritic dermatitis with ulcerated papules, nodules, and plaques on the head and limbs b. Cat = papulonodular dermatitis with abscess-like lesions on legs primarily
287
282. Match the type of fly with the type of body it feeds on. 1. Culicoides spp. 2. Haematobia spp. 3. Tabanids (horse flies) 4. Simulium spp. (black flies) 5. Stomoxys spp. (stable flies) 6. Hippobosca spp. (louse flies) a. Topline b. Ventrum c. Legs d. Neck e. Chest f. Inguinal g. Withers h. Perineal i. Face and ears
Answer: 1 = a, b; 2 = a, b; 3 = b, c, d, g; 4 = b, c, d, i; 5 = a, c, d, e, f; 6 = f, h
288
283. The hypersensitivity reaction seen with Scabies scabiei infestation is due to what? (Multiple Choice) a. Mite feces b. Mite saliva c. Mite chitin d. Mite eggs
a. Mite feces
289
284. What 3 parasites are reportable in sheep?
a. Screw worms (Cochliomyia hominivorax – new world; Chrysiomyia bezziana – old world) b. Psoroptes ovis/P. cuniculi c. Sarcoptes scabiei var. ovis
290
285. Where are the lesions of N. cati infestation usually seen on cats?
a. Medial proximal pinnal margins, then rest of face and entire body
291
286. Describe the clinical signs of N. cati infestation in cats?
a. Minute papules on the skin surface with wrinkled, folded skin with dense, tightly adhered grey crusts with partial alopecia and severe pruritus
292
287. Which of the following is true with regards to Demodex injai? (Multiple Choice) a. D.ijai is longer bodied, compared to D.canis b. D.injai is rarely seen in cats c. The face, dorsum, and paws are the most locations for D.injai d. Terriers, German Shephards, and Shi Tzus may be predisposed to developing D.injai
a. D.ijai is longer bodied, compared to D.canis
293
288. How is calliphorine myiasis commonly classified in sheep?
a. Based upon the location of the anatomic site attacked by the flies (ie – tail strike, head/poll strike, pizzle strike, etc).
294
289. What lesions do Trichobilharzia spp. cause in dogs and cats?
a. Macules and wheels that are intensely pruritic and last 15 -20 hours before maturing into papules and vesicles then healing within 5 – 7 days
295
290. Match the spider type with its name. a. Black Widow b. Red-legged widow c. Brown recluse d. Common brown
Answers: a = 4, b = 2, c = 1, d = 3
296
291. Match the spider bite type with the spider. a. Latrodectus = two small puncture marks, local erythema, granulomatous nodules b. Loxosceles = puncture markers and local erythema, painful vesicles with black/necrotic lesions and ulceration 1. Black Widow 2. Brown recluse 3. Common brown spider 4. Red-legged widow
Answer: a = 1, 4; b = 2, 3 Latrodectus = black widow, red-legged widow Loxosceles = brown recluse, common brown spider
297
292. What happens if a Hypoderma larva is ruptured during nodule removal?
a. An anaphylactoid reaction can result
298
293. True/False – Otodectes cynotis mites are host-specific.
a. False – they can pass between species so treat all animals in the house
299
294. Identify this mite and give its usual location on the animal, knowing that it was found on a chicken recently returned from a bird show.
Answer: Megninia ginglymura (feather mite)
300
295. Give the most likely differential for these signs in a horse.
Answer = Gasterophiliasis – the streaks are due to larval migration
301
296. Why can swarms of black flies be deadly in horses?
a. Saliva of black flies contains a toxin that is heat, alcohol, and ether-stable and increases capillary permeability in order to allow them to suck blood easily b. Large numbers can cause intravascular fluid loss and hypotensive shock
302
297. What three tick-borne diseases are a cause of IMHA in dogs?
a. Babesia species, Rickettsia rickettsii, E. canis
303
298. What are the most common species that cause Calliphorine myiasis in horses? Where are they found?
a. Phormia regina and Phormia terrae-novae (North America) b. Lucilia cuprina (Australia) c. Lucilia sericata (Great Britain and new Zealand)
304
299. What antibody test can be used to confirm Psoroptes ovis infestation?
a. Pso o2 antigen from P. ovis mites – test using ELISA b. Used to identify infestation during lag phase and reduce mite spread across farm
305
300. What systemic effects (5) occur in spider bite recipients? How long does it take?
a. Salivation b. Nausea c. Diarrhea d. Ataxia e. Convulsions f. Paralysis g. Takes 6 – 48 hours post-bite
306
301. Match the cutaneous lesions of helminthic infections with their cause: a. Hookworms b. Pelodera strongyloides c. Strongyloides spp. d. Dracunculus spp. e. Habronemiasis f. Onchocerciasis g. Parafilariasis h. Oxyuriasis 1. Pruritus ani with rat tail in horses 2. Erythema, scaling, crusting +/- pustules and pruritus in areas of direct contact with organic matter 3. SC nodules that ulcerate, mainly on the limbs and abdomen, which can be painful 4. Acute papules and nodules on the neck/shoulders and trunk that produce blood exudate and crust over 5. Ulcerative granulomas with small yellow granules in the diseased tissue of the legs, ventrum, prepuce, medial canthus, lip commissures, and wounds 6. Dermatitis of distal extremities and ventrum and hyperactive “frenzied” behavior 7. Annular lesion in center of forehead, ocular signs, SC nodules in the flexor tendons/suspensory ligaments, and variable lesions on neck/mane and abdomen characteristic of alopecia to scale/crust and plaques 8. Pruritus dermatitis and feet, legs, and ventrum with crusting and erythema of paw pads when pads are present (depending upon species)
Answers: a = 8, b = 2, c = 6, d = 3, e = 5, f = 7, g = 4, h = 1
307
302. Why do lesions resolve in Schistosomiasis infection in dogs and cats?
a. The cercaria are walled off by an acute inflammatory response
308
303. Where does lice infestation tend to occur in camelids, divided by species.
a. Bovicola breviceps = tail head, dorsal midline, side of neck/thorax b. Microthoracius mazzi, M. camelli = head, neck, shoulders, and flanks
309
304. What is the anatomy of an insect?
a. Head = antennae, simple or compound eyes, mouthparts b. Thorax = 2 pairs of wings and 3 pairs of legs c. Abdomen = segmented, terminates in hypopygium or ovipositor d. Body is encased on hard, chitinous plates connected by flexible membranes
310
305. Identify this mite in horses. What mite is it most similar to in clinical signs and treatment?
Answer: a. Ornithonyssus sylvarium (northern fowl mite) b. Treatment and clinical signs most similar to poultry mites (Dermanyssus gallinae)
311
306. What are the three types of lifecycles in insects?
a. Direct development = newly hatched insect is a mini adult b. Incomplete metamorphosis = larvae differ from adult in structure c. Complete metamorphosis: i. Larvae are wormlike and differ from adults in all characteristics ii. Larvae and pupae have characteristic hairs, bristles, and appendages iii. Duration of adult pupal and larval stages vary with species and environment
312
307. What is the life cycle of lice? How long is it?
a. Direct development structure – Nymph hatches, then undergoes 3 stages of molting (L1, L2, L3) to reach adulthood b. Life cycle lasts 14 – 21 days
313
308. Describe the mechanisms by which steroids and cyclosporine lead to demodex overgrowth.
a. Steroids block recognition of chitin by keratinocyte toll like receptors AND block the acquired immune response by interfering with upregulation of IL2, IL4, and CD28 b. Cyclosporine blocks upregulation of IL2, IL4 and CD28
314
309. What are the two Dracunulus spp. and which is present in North America? What are its main hosts?
a. Dracunculus insignis (present in N. America – hosts = dog, raccoon, skunk, mink, fox, otter) b. Dracunculus medinensis
315
310. Distinguish Anoplura and Mallophaga species by diet, activity, and anatomy.
a. Anoplura = sucking lice, eat blood, move slow, tapered head b. Mallophaga = biting lice, eat epithelial debris/hair, move fast, broad head
316
311. Match the type of louse in small animals with its family. a. Trichodectes canis b. Linognathus setosus c. Heterodoxus spiniger d. Felicola subrostatus 1. Anoplura 2. Mallophaga
Answer: a = 2, b = 1, c = 2, d = 2 mallophaga = Trichodectes canis, Hetreodoxus spiniger, Felicola subrostatus Anoplura = Trichodectes canis
317
312. What are the causative agents of pediculosis in sheep?
a. Mallophaga = Damalina ovis (Bovicola ovis) b. Anoplura = Linognathus ovillis and L. pedalis
318
313. What type of chewing louse can be an intermediate host for tapeworms?
a. Trichodectes canis
319
314. What season do lice infestations commonly occur and why?
a. Winter – it is too hot in the summer, which can kill lice
320
315. Match the fly with the season it is most commonly increased as a pest in horses. 1. Summer 2. Fall 3. Spring a. Hippobosca equina (louse fly) b. Haematobia spp. c. Mosquitoes d. Culicoides spp. e. Simulium spp. f. Tabanid spp. g. Stomoxys calcitrans
Answer: 1 = a, b, c, d, f, g; 2 = a; 3 = e Summer: Hippobosca equina, Haematobia spp, Mosquitoes, Culicoides spp, Simulium spp., Tabanid spp. Stomoxys calcitrans Fall: Hippobosca equina (louse fly) Spring: Simulium spp.
321
316. List the species of flies that are strong versus weak fliers.
a. Strong fliers i. Mosquitoes ii. Simulium spp. iii. Tabanid spp. iv. Stomoxys calcitrans v. Haematobia spp. b. Weak fliers i. Culicoides spp. ii. Hippobosca equina
322
317. What are the common clinical signs of lice infestation?
a. Excoriations and secondary dermatitis, papules and crusting, dirty/matted/unkempt haircoat with eggs attached to hairs
323
318. What is the mechanism of action of permethrin? What animal is it toxic to?
a. Toxic to cats b. MOA = blocks Na channels during repolarization, causing spontaneous depolarization and hyperactivity paralysis
324
319. What are the characteristics of Pelodera strongyloides?
a. Saprophytic, free-living nematode with lives in moist-decaying organic matter
325
320. Name four treatments that can be used to kill lice.
a. Fipronil b. Selamectin c. Imidacloprid d. Ivermectin e. Isoxazolines
326
321. A nodule on a dog’s leg is sampled and cytology yields the following. What is the expected diagnosis and how is it treated?
Answer: a. Dracunculiasis b. Treatment = carefully wind worm on a stick over several days, or remove the lesion surgically; decontaminate water supplies and pass water through a fine filter before drinking to prevent recurrence
327
322. A horse presents with crusting and pruritus on the topline. Give four differentials for this condition.
a. Forage mites from horse located under hayloft b. Culicoides gnats c. Dermanyssus gallinae when poulty located above horse stall d. Dermatophilus congolensis e. Staph pyoderma f. Pemphigus foliaceus
328
323. A patient is infested with Otodectes cynotis mites. What (3) cross-reactions do you expect on IDT in this patient? Will they fade after infection is cleared?
a. D. farinae, D. pteronyssinus, A. siro b. Expect to fade within 4 months after infection clears
329
324. What (2) small animal species can be infested by Walchia Americana?
a. Squirrels, other small rodents, cats
330
325. Label the images either Anoplura or Mallophaga.
Answers: a = Mallophaga, b= Anoplura
331
326. Describe the anatomy of fleas (legs, head, body).
a. Small, brown, wingless body that is laterally compressed b. Head contains combs, eyes, antennae, sectorial mouthparts c. Thorax contains 3 segments with 1 pair of legs each, terminating in 2 curved claws
332
327. Match the flea type with the correct photo. a. Ctenocephalides felis felis b. Ctenocephalides canis c. Pulex irritans d. Echidnophaga gallinacea e. Spilopsyllus cuniculi
Answers: a = 3, b = 4, c = 2, d = 5, e = 1
333
328. What is the lifecycle of C. felis felis?
a. Lasts 3 – 4 weeks b. Female flea lays eggs on host, which fall into the environment and hatch in 1.5 – 10 days c. Larvae move to dark, protected areas, then molt three times (L1, L2, L3) d. L3 larvae then enter the pupal phase e. Adults emerge from the cocoon after 8 – 9 days and produce eggs 24 – 36 hours after blood meal
334
329. Describe the clinical signs of habronemiasis in horses.
a. Ulcerative granulomas with intermittent hemorrhage, serosanguinous exudate, and exuberant granulation, mainly on the legs, ventrum, prepuce, urethral process of the penis, medial canthi, lip commissures, or wounds
335
330. Describe the clinical sign of Simulium spp. bites in horses.
a. Painful papules and wheals with hemorrhage and necrosis over the thinly haired areas (ventrum, face/ears, neck, legs)
336
331. What is the most susceptible life stage in the flea life cycle?
Larvae
337
332. What type of movement do flea larvae demonstrate?
a. Negative phototactism and positive geotropism
338
333. Describe the immune environment in dogs with generalized demodicosis.
a. Reduced circulating CD4+ T cells b. Reduced IL-2, IL-21, and TLR6 c. Increased IL-10, TGF-beta, and TLR2
339
334. A dog is positive for Cheyletiella, but you want to test it for environmental allergies. What other allergens can Cheyletiella cause to be positive on a skin test?
a. House dust mite antigens (D. farinae and D. pteronyssinus)
340
335. How does the life cycle of E. gallinacea differ from C. felis felis
a. Female flea burrows into skin and lays eggs b. Eggs hatch on host, molt to larvae, and larvae fall into the environment to complete life cycle
341
336. Match the body location with the type of flea that favors it. a. C. felis felis b. E. gallinacea c. S. cuniculi d. T. penetrans 1. Burrows into skin 2. Face 3. Rump/inguinal regions in dogs, neck/shoulders in cats 4. Pinnae and periauricular areas
Answers: a = 3, b = 2, c = 4, d = 1
342
337. Where are demodex mites located in the skin (3 areas)?
a. Sebaceous glands b. Hair follicles c. Apocrine sweat glands (epitrichial)
343
338. What three tick-borne diseases are responsible for vasculitis in dogs?
a. Rickettsia, E. canis, Bartonella spp.
344
339. A cat was seen frequenting rabbit burrows and is now scratching his ears. What flea type is likely responsible?
a. Spilopsyllus cuniculi
345
340. Name 5 diseases that fleas can be intermediate hosts or vectors for?
a. Tapeworms b. Rickettsia felis c. Bartonella henselae d. Mycoplasma spp. e. Leishmania spp. f. Yersinia pestis (plague)
346
341. Explain how T cell exhaustion leads to overgrowth of demodex in snowballing effect?
a. Demodex overgrowth leads to T cell exhaustion, causing the increased production of IL-10 and TGF-beta, which inhibit the acquired immune response, leading to worsening control of Demodex populations and increased overgrowth
347
342. Describe the expected biopsy findings in a horse with habronemiasis.
a. Variable nodular to diffuse eosinophilic dermatitis with multifocal areas of coagulation necrosis and occasional evidence of larvae within the coagulated areas
348
343. What dog breed is predisposed to Cheyletiellosis?
a. Cocker spaniels
349
344. Dogs with generalized demodicosis may suffer from Tcell exhaustion. What is Tcell exhaustion characterized by? (Multiple Choice) a. Low production of supportive/stimulatory cytokines, such as interleukin (IL)-2 and IL-21, high levels of suppressive cytokines, such as IL-10 and transforming growth factor-beta, and high numbers of circulating CD4+ lymphocytes b. Low production of supportive/stimulatory cytokines, such as interleukin (IL)-2 and IL-21, high levels of suppressive cytokines, such as IL-10 and transforming growth factor-beta, and low numbers of circulating CD8+ lymphocytes c. Low production of supportive/stimulatory cytokines, such as interleukin (IL)-2 and IL-21, high levels of suppressive cytokines, such as IL-10 and transforming growth factor-beta, and high numbers of circulating CD8+ lymphocytes d. Low production of supportive/stimulatory cytokines, such as interleukin (IL)-2 and IL-21, high levels of suppressive cytokines, such as IL-10 and transforming growth factor-beta, and low numbers of circulating CD4+ lymphocytes
d. Low production of supportive/stimulatory cytokines, such as interleukin (IL)-2 and IL-21, high levels of suppressive cytokines, such as IL-10 and transforming growth factor-beta, and low numbers of circulating CD4+ lymphocytes
350
345. A dog is diagnosed with flea infestation. How do you treat the environment (3) and the house (4)?
a. Environment: i. Restrict access to shaded areas (crawl spaces, under decks, woods) ii. Treat with organophosphate powders, diatomaceous earth, or nematodes iii. Apply pyrethrins to vehicle b. Interior: i. Vacuuming with a beater bar, including on the corners of rooms ii. Professional steam cleaning iii. Application of borate compounds into the carpet iv. Application of fenoxycarb/pyriproxyfen
351
346. Where does Pneumonyssus caninum infestation occur on the animal? List five clinical signs.
a. Nasal passages and paranasal sinuses b. Signs = epistaxis/sneezing, facial and periocular pruritus, nasal discharge, head shaking, stridor
352
347. How are Pneumonyssus caninum mites best diagnosed?
a. Rhinoscopy or nasal flushing – mites are visible endoscopically running away from the light
353
348. How do Stomoxys calcitrans flies attack the skin of a horse/dog?
a. Rasping labellar teeth/blades tear open skin b. Plunge entire proboscis and labella into the wound to suck blood
354
349. Where do Stomoxys calcitrans flies tend to attack a dog?
a. Face or ears (attacks ear tips or folded edges of skin when ears are folded)
355
350. What are the clinical signs of Stomoxys calcitrans bites in dogs?
a. Erythema and hemorrhagic crusts due to oozing serum/blood b. Variable pruritus
356
351. What three genera of Tabanid flies attack horses?
a. Tabanus spp, Chrysops spp, and Haematopota spp
357
352. How is Stomoxys calcitrans treated (3 ways)?
a. Fly repellants (permethrins or citronella) b. Imidacloprid/permethrin spot ons c. House indoors until lesions heal d. Topical corticosteroid-antibiotic ointments e. Remove areas for breeding f. Face masks
358
353. Match the tick-borne diseases with the cell location. a. Babesia spp. b. Ehrlichia canis c. Anaplasma phagocytophilum d. Ehrlichia ewingii e. Ehrlichia chaffeensis f. Ricketsia Rickettsii g. Borrelia burgdorferi 1. Monocytes 2. Neutrophils 3. Platelets 4. Erythrocytes 5. Endothelial cells 6. Solid connective tissues
Answer: a = 4, b = 1, 2; c = 2, 3; d = 2, 3; e = 1, 2; f = 5, g = 6
359
354. What environment is ideal for Stomoxys calcitrans breeding?
a. Manure pits/straw piles in stables
360
355. List the management techniques for the following fly species: Mosquitoes, Culicoides gnats, Simulium spp, Tabanid spp, Stomoxys calcitrans, Haematobia irritans, Musca and Hydrotaea spp, and Hippobosca spp.
a. Mosquitoes = drain standing water, premise and animal treatment with insecticides, propane mosquito traps b. Culicoides spp. = fly blankets, stable at night and twilight, fans and treated screens indoors, move away or drain water from ponds or pools, keep in open/breezy pastures, repellant on horses, body suits if needed c. Simulium spp. = stable during the daytime and twilight, frequent application of repellants, ear nets to protect ears d. Tabanid spp. = stable at daytime and twilight, fly sheets to prevent truncal feedings, frequent application of repellants e. Stomoxys calcitrans = destroy breeding grounds on wet hay twice weekly, treat premises with insecticides, insecticides applied to horses f. Haematobia spp = daily application of pyrethroids, control flies on cattle g. Musca and Hydrotaea spp. = fly masks to protect the face, fly sprays, and bandage all wounds or treat with insecticide to prevent habronemiasis h. Hippobosca spp. = routine fly sprays on the body should be sufficient
361
356. Give five differentials for this lesion in a horse or camelid.
a. Cutaneous habronemiasis b. Squamous cell carcinoma c. Trauma with associated exuberant granulation tissue d. Microfilarial dermatitis e. Foreign body granuloma f. Fungal granuloma
362
357. When and where do Simuliidae spp. live and breed?
a. Season = early spring/summer b. Reproduce in shady areas with running water
363
358. Where do black flies tend to bite in dogs and what are their clinical signs?
a. Location of bites = hairless areas (abdomen, head, ears, legs) b. Clinical signs = intensely pruritic papules/crusts/ulcers, hemorrhage and severe excoriations, pinpoint punctures surrounded by a blanched edematous zone
364
359. True/False – Swarms of black flies can be fatal.
a. True – swarms of bites cause anaphylaxis and death
365
360. A cat presents with crusted papular pinnal lesions and pruritic, erosive, crusting dermatitis on the bridge of the nose. Give five differentials for this presentation.
a. Mosquito bite hypersensitivity b. Herpes virus dermatitis c. Feline demodicosis d. Pemphigus foliaceus e. Dermatophytosis f. Solar dermatitis
366
361. What do you expect to find on biopsy of this cat?
Answer: a. Eosinophilic interstitial to diffuse dermatitis b. Infiltrative and necrotizing eosinophilic mural folliculitis c. Sometimes collagen flame figures and eosinophilic intraepidermal microabscesses
367
362. What are the causative agents of habronemiasis? Give 2.
a. Habronema muscae, Habronema majus, Draschia megastoma
368
363. What are your primary differentials for this biopsy in a horse?
Answer: Habronemiasis, Eosinophilic granuloma
369
364. What are the two types of Screw Worms?
a. Chrysomyia bezziana (old world) b. Cochliomyia hominivorax (new world)
370
365. Which flies eat living tissue – Calliphorids (blow flies) or Sarcophagids (flesh flies)
a. Sarcophagids
371
366. Describe the presentation of myiasis in dogs and cats.
a. Lesions over extensive areas with punch-out holes that can coalesce to form broad defects b. Larvae can be visible in tissues and under skin
372
367. List five conditions that predispose to myiasis.
a. Fecal/urinary incontinence b. Constant wet coat c. Fold dermatoses d. Constant salivation/lacrimation e. Poor hygiene
373
368. Describe how all screw worm eggs, larvae, and flies appear morphologically (generally).
a. Eggs = cream-white, oblong, deposited on wound edges in shingle-like pattern b. Larvae = tapered body, mouth hooks on narrow end and breathing spiracles on wide end, body segments are ringed with spines, grow up to 1.5cm long c. Adult = blue-green color with red-orange head and eyes, 2x size of house fly
374
369. How do you treat myiasis in dogs and cats?
a. Clip/clean areas, surgically debride if needed b. Treat larvae with Nitenpyram or Ivermectin c. House patient in screened, fly-free quarters to prevent reinfection
375
370. In what season are dogs most likely to develop severe irritation of the areas of the body in contact with the ground and papulocrustous eruptions caused by small orange mites?
a. Late summer and fall (die when too hot) b. Caused by Eurotrombicula alfreddugesi or Neotrombicula autumnalis
376
371. Describe the appearance of Cuterebra larvae and adults (2nd and 3rd instars).
a. Second larval instar = 5 – 10 mm long, cream to grey color with 10 – 12 body segments, majority encircled by dark spines, well developed cranial mouth hooks b. Third larval instar = dark, thick, heavily spined larvae c. Adult = bee-like and large with vestigial mouthparts (no spines)
377
372. How do animals become infested by Cuterebra?
a. Adults deposit eggs on stones or vegetation near burrow entrances (rabbits, other rodents) and other animals pick up eggs from environment b. Larvae hatch on the body and enter through natural openings or skin penetration then enlarge to form a fistala and pore
378
373. What is the common host of Cuterebra that can affect dogs and cats?
a. Rabbits
379
374. How do you treat Cuterebra infestation?
a. Incise or spread the opening and extract the grub with forceps, taking care not to crush the larvae
380
375. Match the best test method for the following tick-borne diseases: a. Rickettsia rickettsii b. Ehrlichia c. Babesia d. Bartonella e. Borrelia burgdorferi 1. Serology 2. PCR
Answer: a = 1, 2; b = 1, 2; c = 1, 2; d = 2; e = 1
381
376. Match the fly and larvae type with the species. a. Cochliomyia hominivorax b. Chrysomyia bezziana c. Cuterebra
Answers: a = 2, 6; b = 4, 5; c = 1, 3
382
377. A young dog presents with acute onset of facial dermatitis with multiple nodular lesions that are crusted due to pruritus and scratching. Cytology shows numerous eosinophils and no sign of infection. Give three differentials for this presentation.
a. Facial eosinophilic folliculitis or furunculosis after insect bite b. Puppy strangles c. Contact reaction
383
378. What type of venom is present in fire ants and what does it do?
a. Solenopsin A (an alkaloid) b. Cytotoxic and hemolytic
384
379. What environment favors Dirofilaria immitis infections?
a. Warm areas where Aedes, Anopheles, and Mansonia mosquito species live
385
380. True/False – If a rabbit has Cheyletiella, it cannot pass it to a cat in the house.
a. False – mites can transfer between dogs, cats, and rabbits
386
381. Describe the unique biopsy findings seen with fire ant stings.
a. Vertically oriented linear bands of full thickness dermal necrosis with surrounding edema and eosinophilia
387
382. What types of caterpillars can case reactions and why?
a. Thaumetopoea species (Pine and Oak Caterpillars) b. Etiology = bristles on caterpillars contain thaumetopoein, which causes mast cell degranulation and histamine release
388
383. What are three clinical signs of caterpillar reaction in dogs and cats?
a. Acute facial pruritus, urticaria, and angioedema (mainly the lips and muzzle) with a swollen tongue and drooling b. Can develop necrosis on portions of the tongue if severe
389
384. Differentiate Eutrotrombicula from Otodectes mites in two ways.
a. Eurotrombicula show intense red-orange color and a tight adherence to skin
390
385. What are the clinical signs of horse fly bites (Tabanid species)?
a. Painful, pruritic papules and wheals with a central ulcer and hemorrhagic crust on the ventrum, neck, legs, and withers b. Rivulets of blood appear at bite sites, attracting non-biting flies and their larvae
391
386. Match the type of Cheyletiella with the primary host species. a. Cheyletiella yasguri b. Cheyletiella parasitivorax c. Cheyletiella blakei d. Cheyletiella eruditus 1. Cat 2. Rabbit 3. Free living 4. Dog
Answer: a = 4, b = 2, c = 1, d = 3
392
387. What fly species is associated with leukoderma in horses?
a. Haematobia irritans (horn flies)
393
388. What are two species responsible for myiasis?
a. Blowflies b. Screw worms
394
389. What is the life cycle of the Habronema helminth?
a. Adults live in the horse’s stomach (Draschia spp. live in nodules) b. Eggs and larvae are passed in horse feces and ingested by maggots of the housefly or stable fly c. Infectious larvae are deposited by flies on the horse (especially in moist areas or open wounds) d. Larvae penetrate the skin and migrate without completing the life cycle OR they are swallowed by the horse and complete their life cycle in the horse’s stomach
395
390. What is the life cycle of the habronemiasis parasites in horses?
a. L1 larvae hatch from eggs while passing through stomach of infected equid b. L1s are ingested from manure by housefly/stablefly maggots c. L1s mature to L3s inside maturing flies d. L3s are carried to open wounds on equids by flies e. Equids can develop cutaneous habronemiasis or consume the larvae during grooming, leading to gastritis, gastric ulceration, and colic in some cases.
396
391. With regards to canine demodicosis, which of the following is false? (Multiple Choice) a. The presence of anti-Demodex humoral antibodies has been documented in the dog b. There is evidence that chitin can be recognized by keratinocyte Toll-like receptors (TLRs), eliciting an innate immune response c. IL-2, IL-4, and CD27 are interleukins associated with the acquired immune response to the demodex mite d. Immunosuppression can result in an increased risk of developing a Demodex mite overgrowth
a. The presence of anti-Demodex humoral antibodies has been documented in the dog
397
392. What is the life cycle of Demodex canis?
a. Adult mites live in the hair follicles, sebaceous glands, and apocrine sweat glands – females lay eggs in these areas b. Eggs hatch into six-legged larvae c. Larvae molt to eight-legged nymphs, which then molt to adults d. All stages occur in the same areas of the skin (do not leave the host)
398
393. Topical fluralaner (Bravecto®), has been applied to a cat for treatment of feline demodicosis. What is the mechanism of action of this medication? (Multiple Choice) a. Binds sites on nicotinic acetylcholine receptors (nAChRs) of insect nervous system b. Binds glutamate gated chloride channels in invertebrate nerve and muscle cells causing hyperpolarization of insect nervous systems c. Modulates the action of glutamate acid decarboxylase of insect nervous systems d. Inhibits y-aminobutyric acid-gated chloride channels and L-glutamate-gated channels of insect nervous systems
d. Inhibits y-aminobutyric acid-gated chloride channels and L-glutamate-gated channels of insect nervous systems

Vet Derm Parasitology 8% (1 decks)

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