Nematodes of Horses

Question 1

Trichostrongylus axei (site)

Answer 1

stomach

Question 2

Trichostrongylus axei (Pathogenesis)

Answer 2

Cushion-like thickening of glandular part of stomach

Question 3

Trichostrongylus axei (route of infection)

Answer 3

Ingestion of L3 – non-migratory in host

Question 4

Habronema and Draschia (site)

Answer 4

Stomach

Question 5

Habronema and Draschia (Route of infection)

Answer 5

Adults – stomach, Larvae – skin wounds (“summer sores”), conjunctivae

Question 6

Habronema and Draschia (eggs)

Answer 6

1 species lays larvated egg – thin shelled & very elongated;
other species lay larvae.
Eggs usually don’t float.

Question 7

Habronema and Draschia (Pathology)

Answer 7

Draschia – lg. stomach nodules

Habronema - gastritis

Question 8

Parascaris equorum (site)

Answer 8

Small intestine of young horses (under 6 months)

Question 9

Parascaris equorum (egg)

Answer 9

spherical, pitted thick shell, brown

Question 10

Parascaris Equorum (Importance)

Answer 10

Verminous pneumonia; rarely intestinal obstruction/rupture

Question 11

Strongyloides westeri (host)

Answer 11

Horse; donkey (foals)

Females parasitic; may be free-living

Question 12

Large Strongyles (common name)

Answer 12

red worm

Question 13

Large Strongyles (site)

Answer 13

cecum/colon

Question 14

Large Strongyles (type of feeding)

Answer 14

draw a mass of intestinal mucosa into buccal capsule and digest it – leaves scars with raised heavy fibrous rim – easily seen on the gut wall.

Question 15

Most important nematode of the horse

Answer 15

Strongylus vulgaris

Question 16

Importance of strongylus vulgaris

Answer 16

most common
gut lesions -erosion and blood letting
Serious action on large arterial trunks, esp. cranial mesenteric a. May be fatal.
Occasional cerebrospinal nematodiasis

Question 17

importance of small strongyles

Answer 17

With heavy infection, catarrhal enteritis ( is an inflammation of the mucous membrane of the. small intestine), progressive fibrosis (characterized by the development of large conglomerate masses of dense fibrosis (usually in the upper lung zones),), thickening of gut wall

Question 18

Cyathostominae

Answer 18

Small red worms

small strongyles

Question 19

What eggs have the same appearance?

Answer 19

Trichostrongylus, small and large strongyles

Question 20

Control of strongyles

Answer 20

Deworm adults every 2-3 months
Mixed grazing – have ruminants graze horse pasture
Small paddocks – clean feces away once/week

Question 21

Oxyuris equi (common name)

Answer 21

Pinworm of horses

Question 22

Oxyuris Equi (site)

Answer 22

small intestine; migrate to large intestine – anus to lay eggs

Question 23

Oxyuris Equi (eggs)

Answer 23

Operculated; flattened on one side

Question 24

Dictyocaulus arnfeldi (common name)

Answer 24

lungworm of horse

Question 25

Dictyocaulus arnfeldi (site)

Answer 25

large bronchioles, bronchi, trachea

Question 26

Dictyocaulus arnfeldi (host)

Answer 26

Equidae – donkeys esp.; ruminants; camels

Question 27

Setaria equina (site)

Answer 27

In peritoneal cavity,either free or on serosal surface

Question 28

Setaria equina (importance)

Answer 28

harmless; but if it migrates it can cause blindness

Question 29

Thelazia lacrimalis (host)

Answer 29

most mammals

Question 30

Thelazia lacrimalis (location)

Answer 30

orbital region

Question 31

Thelazia lacrimalis (importance)

Answer 31

rarely a problem