parasitology - large animal GI

Question 1

Haemonchous contortus
what it does
CS
tx

Answer 1

causes anemia and hypoproteinemia in sheep and goats
its the bloodsucker of the abomasum
CS: chronic weight loss, doing poorly, pale gums (NO diarrhea!)
tx: fenbendazole - some resistance seen

Question 2

Nematodirus
CS
what it coincides with
what it looks like

Answer 2

CS: young animals with profuse watery diarrhea, anorexia, weight loss, and dehydration
coincides with coccidiosis in the spring
- looks ellipitcal in shape with sharply curved poles and 2 - 8 blastomeres surrounded by fluid-filled cavity

Question 3

ostertagia ostertagii Type 1
CS in what type of cow
when is it seen
infective stage
egg counts

Answer 3

CS: acute weight loss and diarrhea in NAIVE cows

• seen in winter and spring
• infected with large numbers of L3 from contaminated pastures
• egg counts are HIGH

Question 4

ostertagia ostertaggi Type 2 --> nickname
CS in what type of cow
when is it seen
egg counts
what the typical infection looks like

Answer 4

nickname –> moroccan leather
CS: chronic weight loss and diarrhea in OLDER cows
- seen in autumn and winter
- low egg counts
- typical infection is lots of inhibited L4 that rapidly emerge and will see thousands of larve in abomsum like “moroccan leather”

Question 5

coccidiosis
which one infects herbivores
which one infects carnivores

Answer 5

coccidiosis
Eimeria –> herbivores
isospora –> carnivores

Question 6

what disease does coccidiosis cause in calves?
at what age?
what toxin does it make and what does it cause?
what is the typical presentation?
how do you treat it?

Answer 6

nervous coccidiosis

• in calves <1 year old
• makes a heat labile neurotoxin
• typical scenario: diarrhea followed by nervous signs
• tx w/ amprolium (monensin, sulfa-containing drugs)

Question 7

strongyloides
what kind of worm is it?
how does infection occur?

Answer 7

its an intestinal threadworm
migrates to intestines by penetrating oral mucosa or skin, enters bloodstream, will go through heart and lungs where they are coughed up and swallowed and then enter the intestines

Question 8

Monenzia
what kind of worm is it?
what shape is it?
is it pathogenic?

Answer 8

tapeworm
rectangular structure (or triangular)
usually non-pathogenic, can cause intestinal stasis

Question 9

oxyuris equi
what kind of worm is it?
CS
where are they found?
dx?

Answer 9

= pinworms
CS: anal pruritus tail rubbing, alopecia, around tail and perineal area
- female worms crawl out of anus and cement eggs to perineal region, larvae hatch and cause discomfort
- dx: scotch tape prep to look for eggs

Question 10

parascaris equorum
kind of worm
CS in what kind of animals
tx

Answer 10

= roundworm (ascarid)

• CS in young foals = respiratory signs (bc it migrates thru lungs and predisposes them to infection) along w/ weight loss, diarrhea and colic - intestinal impaction
• CS in adult horses = immune mediated hypersensitivity
• tx: antihelminitics SLOWLY - a massive die off will cause an impaction

Question 11

anoplocephala magna
A. perfliata
paranoplocephala mamillana
what kind of worms? 
CS
seen in which animals
tx

Answer 11

tapeworms!
CS: chronic gastritis, weight loss - penetrate mucosa cuasing ulceration and thickening
- affects ruminants, and horses around cattle
- tx: benzimidazole, ivermectin

Question 12

Gasterophilus intestinalis
what kind of worm?
- presentation
- CS

Answer 12

bot fly larvae, stomach bot

• presentation: yellowish eggs on medial aspect of cannon bone
• CS: usually no clinical signs though may see gastritis or stomach rupture