Exam 2

Question 1

Ostertagia ostertagi is the most important nematode parasite of cattle. This nematode causes disease in cattle primarily by:

a) Blood loss from wounds in the abomasum left by feeding adult worms
b) Destruction of the abomasal glands due to larval growth within these glands
c) Intestinal inflammation resulting from secretion of toxins from adult worms
d) Destruction of the liver, spleen, and sometimes kidneys as larvae migrate through the body before returning to the abomasum to complete their development
e) Destruction of the small intestinal mucosa, particularly in the duodenum, due to extensive larval migration in the mucosa

Answer 1

b) Destruction of the abomasal glands due to larval growth within these glands

Question 2

Thelazia, an eyeworm of cattle and horses that is occasionally found in small animals, is transmitted via:

a) Mosquitoes
b) Sandflies
c) Ticks
d) Keds
e) Muscid flies

Answer 2

e) Muscid flies (IH)

Question 3

Lesions due to infection with Ascaris suum include:

a) Bilateral ocular opacities
b) Fistulous tracts on the skin overlying the tail head
c) Milk spot lesions in the liver due to scarring
d) Laryngeal scarring causing abnormal vocalizations
e) Grossly thickened renal capsule and necrosis of perirenal fat

Answer 3

c) Milk spot lesions in the liver due to scarring

Question 4

You examine a herd of beef cattle with an afebrile respiratory disease that has not responded to antibiotics. Several of the younger animals are coughing. You suspect infection with a respiratory parasite. What diagnostic test would be most likely to reveal evidence of infection with the most likely parasitic etiologic agent?

a) Direct smear for motile protozoa
b) Blood antigen test
c) Baermann exam for larvae in feces
d) Fecal float for ascarid eggs
e) Fecal sedimentation for trematode eggs

Answer 4

c) Baermann exam for larvae in feces

Question 5

Infection of sheep and goats with Bunostomum would be expected to cause:

a) Abortion storms
b) Clinically inapparent respiratory disease
c) Severe central nervous system disease
d) Anemia
e) Mucopurulent ocular and nasal discharge

Answer 5

d) Anemia (hookworms blood suckers, but in our lecture, it was said that Bunostomum causes negligible blood loss)

Question 6

The preferred method for detecting the larvae of Aelurostrongylus abstrusus in cats is:

a) Fecal sedimentation
b) Fecal filtration
c) Baermann examination of feces
d) Direct smear of feces
e) Thoracic radiographs

Answer 6

c) Baermann examination of feces

Question 7

Several elk and moose in a mixed-species hoof stock exhibit at a wildlife park develop neurologic disease, including ataxia and torticollis. However, the white-tailed deer in the exhibit are all normal. You suspect a nematode may be responsible. If so, how did the animals become infected?

a) Ingestion of snail or slug intermediate hosts infected with third-stage larvae (L3)
b) Ingestion of first-stage larvae (L1) shed in feces of infected deer
c) Ingestion of third-stage larvae (L3) free on pasture
d) Skin penetration by first-stage larvae (L1) shed in feces of infected deer
e) Skin penetration of third-stage larvae (L3) free on pasture

Answer 7

a) Ingestion of snail or slug intermediate hosts infected with third-stage larvae (L3)

(Parasite is Parelaphostrongylus tenuis)

Question 8

You examine a herd of goats with pale mucous membranes and submandibular edema. Necropsy examination of one goat reveals nematodes in the abomasum with a characteristic spirally-striped, “barber pole” appearance. What parasite is this most likely to be?

a) Teladorsagia circumcincta
b) Trichostrongylus colubriformis
c) Haemonchus contortus
d) Nematodirus battus
e) Cooperia punctate

Answer 8

c) Haemonchus contortus

Question 9

A five-year old intact female Labrador retriever presents for routine spay. At laparotomy, a stout red nematode nearly 1 meter in length is found free in the abdominal cavity. What parasite is this?

a) Dioctophyme renale
b) Dipylidium caninum
c) Dipetalonema reconditum
d) Dirofilaria immitis
e) Diphyllobothrium latum

Answer 9

a) Dioctophyme renale (giant kidney worm of carnivores)

Question 10

Which organ is most commonly affected in cats that develop disease due to infection with Dirofilaria immitis?

a) Liver
b) Lung
c) Kidney
d) Central nervous system
e) Skeletal muscle

Answer 10

b) Lung

Question 11

Disease caused by cyathostomes, or small strongyles, in horses generally results from:

a) Larval irritation in the skin resulting in seasonal dermatitis, commonly referred to as summer sores
b) Extensive migration of larvae throughout the liver, lungs, and kidneys of infected horses
c) Aggressive blood feeding activity of the adult worms
d) Tracheal and bronchial irritation due to presence of adult worms in the airways
e) Emergence of encysted larvae from the intestinal mucosa

Answer 11

e) Emergence of encysted larvae from the intestinal mucosa

Question 12

What diagnostic test is best able to detect eggs in the feces of a 1-week-old puppy infected with ascarids and hookworms?

a) Sodium nitrate fecal flotation
b) Zinc sulfate fecal flotation with centrifugation
c) Direct smear
d) Fecal sedimentation
e) None of these methods because eggs will not be present

Answer 12

e) None of these methods because eggs will not be present

Question 13

Puppies that die at 2 days of age because of large numbers of larval nematodes migrating and molting in their lungs are most likely infected with which parasite?

a) Toxoscaris leonina
b) Trichuris vulpis
c) Trichostrongylus axei
d) Toxocara canis
e) Physaloptera

Answer 13

d) Toxocara canis (has transplacental transmission)

Question 14

The currently-available monthly heartworm preventatives protect dogs from acquiring infection with adult heartworms by:

a) Killing any larvae that may have been acquired by the dog in the preceding 30-day period
b) Providing complete protection against any newly-introduced larval worms for more than 30 days following treatment
c) Rendering the adult worms sterile, thereby preventing production of additional worms in an infected dog
d) Altering the pheromone profile of treated dogs thereby discouraging feeding by vector mosquitoes
e) Serving as a microfilaricide, thereby eliminating young worms before they are able to develop to adults in a treated dog

Answer 14

a) Killing any larvae that may have been acquired by the dog in the preceding 30-day period

Question 15

A four-year-old mixed breed dog housed in a small, dirt-floored pen presents with a history of weight loss, diarrhea, and tenesmus. The feces is soft and contains bright red blood. What parasite is most likely to cause the symptoms described?

a) Dipylidium caninum
b) Ancylostoma caninum
c) Toxocara canis
d) Trichuris vulpis
e) Taenia pisiformis

Answer 15

d) Trichuris vulpis

Question 16

Neurocystocercosis develops in people following ingestion of eggs of Taenia solium found in:

a) Undercooked meat of infected pigs
b) Feces of infected pigs
c) Feces of infected cows
d) Feces of infected people
e) Undercooked meat from infected cows

Answer 16

d) Feces of infected people (Neural signs occur in intermediate host, usually swine, but can also be people)

Question 17

The short prepatent period of this nematode insures that eggs of this parasite are likely to be the first detected in a fecal float on a young foal:

a) Oxyuris equi
b) Stongylus vulgaris
c) Parascaris equorum
d) Strongyloides westeri
e) Drashia megastoma

Answer 17

d) Strongyloides westeri

Question 18

A mixed breed dog that is housed outdoors on soil in a run presents with lesions on its ventral and dorsal surfaces of all four feet, sternum, and ventral abdomen. The areas are erythematous, thickened, and alopecic. The owner informs you that ever since the dog was adopted two years ago from a neighbor, the dog has only had yearly routine vaccinations (rabies, DA2PP). The organism responsible for these lesions is most likely:

a) Aelurostrongylus abstrusus
b) Ancylostoma tubaeforme
c) Protostrongylus rufescens
d) Ancylostoma caninum
e) Bunostomum phlebotomum

Answer 18

d) Ancylostoma caninum (due to skin penetration)

Question 19

A 5-year-old intact male cat present with choleostasis and liver failure. Fecal sedimentation reveals an operculated egg with a fully-formed miracidium. The most likely diagnosis is:

a) Fasciola hepatica
b) Platynosomum fastosum
c) Taenia taeniaeformis
d) Spirometra mansonoides
e) Dipylidium caninum

Answer 19

b) Platynosomum fastosum
(Fasciola hepatica is mostly ruminants with the occasional carnivore, where Platynosomum fastosum is the liver fluke of cats)

Question 20

This parasite is unusual among the trichostrongyles in that it not only infects ruminants, but also infects many other host species including horses and pigs. It is one of the few parasites of potential concern in a mixed-species grazing situation.

a) Cooperia punctata
b) Trichostrongylus axei
c) Haemonchus contortus
d) Nematodirus battus
e) Ostertagia ostertagi

Answer 20

b) Trichostrongylus axei

in stomach of horses and abomasum of cattle, sheep, and goats

Question 21

Foals become infected with Parascaris equorum:

a) When they ingest larvated eggs from a contaminated environment
b) Transplacentally (in utero) from the somatic tissue stores in the mare
c) Transmammarily (via milk) from larvae mobilized from mare somatic tissue
d) By inadvertent ingestion of insect intermediate hosts when grazing
e) By inadvertent ingestion of avian tissues in contaminated feed

Answer 21

a) When they ingest larvated eggs from a contaminated environment

Question 22

49) The main significance of Acanthocheilonema (=Dipetalonema) reconditum in veterinary medicine is:
a) Severe disease caused by death of microfilaria following treatment for Dirofilaria immitis
b) Pathology seen in infected fleas and future potential for biological flea control
c) Severe pathology caused by migration of this subcutaneous worm
d) Microfilaria are similar in appearance to those of Dirofilaria immitis and thus may confound diagnosis
e) Severe disease caused by death of subcutaneous adult nematodes following treatment for Dirofilaria immitis

Answer 22

d) Microfilaria are similar in appearance to those of Dirofilaria immitis and thus may confound diagnosis

Question 23

Although now rarely seen in managed horses, the migrating larvae of this large strongyle can cause severe inflammation in the wall of the cranial mesenteric artery, and this nematode was, at one time, the most commonly diagnosed cause of equine colic:

a) Strongylus minor
b) Strongylus edentatus
c) Strongylus equinus
d) Strongylus cyathostomus
e) Strongylus vulgaris

Answer 23

e) Strongylus vulgaris

Question 24

You perform rectal palpation on a 2-year-old standardbred horse with a history of acute diarrhea and colic. When you withdraw your arm you notice several bright red larval worms wriggling around on the palpation sleeve. What equine nematodes are most likely responsible?

a) Ascarids (Parascaris equorum)
b) Large strongyles (Strongylus spp)
c) Small strongyles (cyathostomes)
d) Pinworms (Oxyuris equi)
e) Threadworms (Strongyloides westeri)

Answer 24

c) Small strongyles (cyathostomes)

Question 25

A 5-month-old spaniel puppy vomits a mass of thick stout white nematodes. On close inspection, you note the presence of three lips at the anterior end of each of the worms. What parasite is this most likely to be?

a) Toxocara canis
b) Toxocari cati
c) Toxascaris leonina
d) Ancylostoma caninum
e) Trichuris vulpis

Answer 25

a) Toxocara canis

Question 26

A dog that chases and eats wild rabbits is most likely to become infected with which cestode?

a) Echinococcus granulosus
b) Taenia saginata
c) Diphyllobothrium latum
d) Dipylidium caninum
e) Taenia pisiformis

Answer 26

e) Taenia pisiformis

Question 27

Which of the following drugs would be the best choice for the treatment of a Fasciola hepatica infection in a pregnant beef cow?

a) Albendazole
b) Fenbendazole
c) Eprinomectin
d) Clorsulon
e) Praziquantel

Answer 27

d) Clorsulon

Question 28

An egg (ova) of Pearsonema plica was detected on urine sediment examination of a 4-year-­old neutered male mixed-breed dog with a history of cystitis. How did the dog become infected with this parasite?

a) Skin penetration of third-stage larvae
b) Ingestion of egg containing third-stage larvae
c) Ingestion of earthworm containing first-stage larvae
d) Ingestion of dung beetle containing third-stage larvae
e) Migration of third-stage larvae up urethra to embed in urinary bladder mucosa

Answer 28

c) Ingestion of earthworm containing first-stage larvae

Question 29

The term “measly beef” refers to the presence of:

a) Eggs of Taenia saginata in muscle tissue
b) Cysticerci of Taenia saginata in muscle tissue
c) Sarcocysts (tissue cysts) of Sarcocystis in muscle tissue
d) Tissue cysts of Toxoplasma gondii in muscle tissue
e) Tissue cysts of Neospora caninum in muscle tissue

Answer 29

b) Cysticerci of Taenia saginata in muscle tissue

Question 30

A five-year-old horse presents with tail rubbing and anal pruritus. You suspect infection with the equine pinworm, Oxyuris equi. What diagnostic test is preferred to recover the eggs of this parasite?

a) Direct smear
b) Passive fecal flotation with sodium nitrate
c) Centrifugal fecal flotation with sugar solution
d) Fecal sedimentation
e) Scotch tape test

Answer 30

e) Scotch tape test

Question 31

A litter of 2-week-old puppies presents with acute lethargy. On physical examination the puppies are moribund, cold, and have markedly pale mucous membranes. You suspect acute anemia due to hookworm infection. The next step in managing these puppies is:

a) Prophylactically deworm with pyrantel pamoate
b) Perform a fecal flotation and only deworm if eggs are detected
c) Perform CBC, serum chemsitry, U/A, and abdominal radiographs on each pup
d) Hold for quiet observation for 48 hours to monitor progression of disease
e) Bathe each puppy to insure ectoparasites are eliminated

Answer 31

a) Prophylactically deworm with pyrantel pamoate

Question 32

What aspect of the life cycle of Habronema and Draschia spp. accounts for the seasonal pattern seen in cutaneous habronemiasis, or summer sores, in affected horses?

a) The bacterial organisms which cause the secondary infections responsible for the lesions only flourish in the humid summer months
b) The larval stages of these nematodes become hypobiotic in the winter and are thus less irritating to horses
c) The ticks which transmit these parasites are only active in the summer months
d) The activity of the muscid flies which serve as vector and intermediate host of these nematodes is greatly reduced in the winter months
e) Horses are ridden less in the winter months and thus the abrasive sores are less likely to develop

Answer 32

d) The activity of the muscid flies which serve as vector and intermediate host of these nematodes is greatly reduced in the winter months

Question 33

Which of the following antiparasitic agents is most suitable for use against immature stages of Fasciola hepatica?

a) Fenbendazole
b) Ivermectin
c) Praziquantel
d) Albendazole
e) Clorsulon

Answer 33

e) Clorsulon

Question 34

96) Cats infected with Dirofilaria immitis:
a) Routinely develop severe reactions to administration of monthly heartworm preventatives due to rapid death of microfilaria
b) Are usually microfilaremic, allowing diagnosis via Knott or filter test or examination of a wet mount of whole blood
c) Occasionally develop disease due to aberrant migration of the worms, including to the central nervous system or ocular tissues
d) Often harbor large numbers (>50) of adult worms
e) Have not been shown to develop any significant clinical disease due to infection

Answer 34

c) Occasionally develop disease due to aberrant migration of the worms, including to the central nervous system or ocular tissues

Question 35

Anthelmintic resistance has been widely documented to occur in small strongyles (= cyathostomes) of horses with which of the following dewormers?

a) Pyrantel
b) Fenbendazole
c) Ivermectin
d) Moxidectin
e) A and B

Answer 35

e) A and B

Question 36

A 5-year-old neutered male golden retriever from Oregon with a history of salmon consumption presents with high fever, lethargy, diarrhea, and generalized lymphadenopathy. Fecal sedimentation examination reveals small operculated eggs. What is the most appropriate pharmacotherapy?

a) Ivermectin
b) Doramectin
c) Doxycycline
d) Pyrantel
e) Lincomycin

Answer 36

c) Doxycycline (parasite is Nanophyetus salmincola)

Question 37

Neonatal porcine diarrhea develops subsequent to infection with:

a) Cystoisospora (Isospora) suis
b) Eimeria porci
c) Eimeria scabra
d) Macracanthorhynchus hirudinaceus
e) Stephanurus dentatus

Answer 37

a) Cystoisospora (Isospora) suis

Question 38

Decoquinate is continually fed to confined poultry in order to control:

a) Leucocytozoon spp.
b) Isospora spp.
c) Ascaridia spp.
d) Trichomonas gallinae
e) Eimeria spp.

Answer 38

e) Eimeria spp.

Question 39

Which of the following types of adult cattle are, as a group, most likely to be infected with the causative agent of bovine trichomoniasis?

a) Bulls > 4 years of age
b) Cows
c) Steers
d) Virgin heifers
e) A and B

Answer 39

e) A and B

Question 40

A client has just returned from a winter vacation to Greece where she adopted a stray dog. She is concerned about the multiple patches of alopecia on the dog’s face and pinnae; you also note that the nasal planum is depigmented. With leishmaniasis as your top differential diagnosis, which statement is the least accurate?

a) The organism is found intracellularly in erythrocytes.
b) It is unknown exactly how infection is spread from dog to dog within North America.
c) This disease is only very rarely reported in cats.
d) Horses can also suffer from the cutaneous form.
e) The incubation period can be as long as several years.

Answer 40

a) The organism is found intracellularly in erythrocytes.

Question 41

Which of the following are effective for the treatment of clinical coccidiosis in cattle?

a) Amprolium
b) Metronidazole
c) Decoquinate
d) A and B
e) All three drugs listed

Answer 41

a) Amprolium (CAPC answer, but he also mentions Decoquinate in his powerpoint)

Question 42

Pigs become infected with the thorny-headed worm, Macracanthorhynchus hirudinaceus, upon:

a) Ingestion of free L3 from the environment
b) Skin penetration by L3 from the environment
c) Ingestion of L3 in larvated eggs from the environment
d) Ingestion of an infected beetle containing a cystacanth stage
e) Ingestion of L1 in the fresh feces of a fellow pig

Answer 42

d) Ingestion of an infected beetle containing a cystacanth stage

Question 43

Which of the following drugs is effective for treating Giardia and has the least toxicity problems associated with its use in dogs and cats?

a) Ivermectin
b) Milbemycin
c) Metronidazole
d) Albendazole
e) Fenbendazole

Answer 43

e) Fenbendazole