Exam 2 Flashcards
(43 cards)
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
b) Destruction of the abomasal glands due to larval growth within these glands
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
e) Muscid flies (IH)
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
c) Milk spot lesions in the liver due to scarring
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
c) Baermann exam for larvae in feces
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
d) Anemia (hookworms blood suckers, but in our lecture, it was said that Bunostomum causes negligible blood loss)
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
c) Baermann examination of feces
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
a) Ingestion of snail or slug intermediate hosts infected with third-stage larvae (L3)
(Parasite is Parelaphostrongylus tenuis)
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
c) Haemonchus contortus
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
a) Dioctophyme renale (giant kidney worm of carnivores)
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
b) Lung
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
e) Emergence of encysted larvae from the intestinal mucosa
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
e) None of these methods because eggs will not be present
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
d) Toxocara canis (has transplacental transmission)
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
a) Killing any larvae that may have been acquired by the dog in the preceding 30-day period
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
d) Trichuris vulpis
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
d) Feces of infected people (Neural signs occur in intermediate host, usually swine, but can also be people)
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
d) Strongyloides westeri
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
d) Ancylostoma caninum (due to skin penetration)
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
b) Platynosomum fastosum
(Fasciola hepatica is mostly ruminants with the occasional carnivore, where Platynosomum fastosum is the liver fluke of cats)
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
b) Trichostrongylus axei
in stomach of horses and abomasum of cattle, sheep, and goats
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
a) When they ingest larvated eggs from a contaminated environment
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
d) Microfilaria are similar in appearance to those of Dirofilaria immitis and thus may confound diagnosis
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
e) Strongylus vulgaris
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)
c) Small strongyles (cyathostomes)
