Endoparasites Of Horses

Front 1

Equine ascarid, equine roundworm

Back 1

Parascaris equorum

Front 2

Prepatent is 75-80 days

Back 2

Parascaris equorum

Front 3

Largest of the equine nematodes

Back 3

Parascaris equorum

Front 4

Adults may be passed in feces and may grow to 50cm

Back 4

Parascaris equorum

Front 5

Nematodes found in the small intestine of young foals

Back 5

Parascaris equorum

Front 6

Parascaris equorum

Back 6

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Front 7

Parascaris equorum

Back 7

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Front 8

Parascaris equorum

Back 8

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Front 9

Parascaris equorum

Back 9

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Front 10

Strongylus vulgarus, S edentatus, S. equinus

Back 10

Large Strongyles

Front 11

eggs (large or small) are virtually identical, species identification is achieved by fecal culture

Back 11

Large Strongyles

Front 12

Listed as “strongyle type” in medical record when found on flotation

Back 12

Large Strongyles

Front 13

Strongyles

Back 13

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Front 14

Strongyles

Back 14

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Front 15

Strongyles

Back 15

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Front 16

Strongyles

Back 16

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Front 17

Strongyles

Back 17

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Front 18

Strongyles

Back 18

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Front 19

Intestinal threadworm of horses
Nematodes

Back 19

Strongyloides westeri

Front 20

Only the female is parasitic in the host

Back 20

Strongyloides westeri

Front 21

Prepatent period 5-7 days

Back 21

Strongyloides westeri

Front 22

Can be passed through milk to foal

Back 22

Strongyloides westeri

Front 23

Causes diarrhea in foals

Back 23

Strongyloides westeri

Front 24

Intestinal threadworm of horses
Nematodes

Back 24

Strongyloides westeri

Front 25

Only the female is parasitic in the host

Back 25

Strongyloides westeri

Front 26

Prepatent period 5-7 days

Back 26

Strongyloides westeri

Front 27

Can be passed through milk to foal

Back 27

Strongyloides westeri

Front 28

Causes diarrhea in foals

Back 28

Strongyloides westeri

Front 29

Strongyloides westeri

Back 29

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Front 30

Strongyloides westeri

Back 30

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Front 31

Strongyloides westeri

Back 31

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Front 32

Pinworm of horses

Back 32

Oxyuris equi

Front 33

Adults found in cecum, colon and rectum

Back 33

Oxyuris equi

Front 34

Adult females attach eggs to exterior of anus with sticky material that causes anal puritis in infected horses

Back 34

Oxyuris equi

Front 35

Adult worms often seen protruding from the anus

Back 35

Oxyuris equi

Front 36

Eggs may be larvated

Back 36

Oxyuris equi

Front 37

Prepatent 4-5 months

Back 37

Oxyuris equi

Front 38

Eggs can be recovered by using tape impressions of anus, as well as a scarping the surface of the anus

Back 38

Oxyuris equi

Front 39

Due to the intense itching, horses will rub their rumps against solid objects, causing broken hairs on the tail head

Back 39

Oxyuris equi

Front 40

Oxyuris equi

Back 40

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Front 41

Oxyuris equi

Back 41

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Front 42

Oxyuris equi

Back 42

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Front 43

Equine lungworm

Back 43

Dictyocaulus arnfieldi

Front 44

Found in bronchi and bronchioles of horses, mules and donkeys

Back 44

Dictyocaulus arnfieldi

Front 45

Embryonated eggs

Back 45

Dictyocaulus arnfieldi

Front 46

Eggs can be found on fresh (<24 hrs old) feces

Back 46

Dictyocaulus arnfieldi

Front 47

Larvae hatch from eggs within a few hours

Back 47

Dictyocaulus arnfieldi

Front 48

Prepatent 42-56 days

Back 48

Dictyocaulus arnfieldi

Front 49

Dictyocaulus arnfieldi

Back 49

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Front 50

Adult gastrointestinal nematodes

Back 50

Habronema sp

Front 51

Aberrant larvae (deposited by flies) produce cutaneous habronemiasis, aka summer sores

Back 51

Habronema sp

Front 52

Lesions vary in size and have an uneven surface that consists of a soft reddish-brown material and covers a mass of firmer granulation tissue
Seen on parts of the body that are liable to be injured: legs, withers, male genitalia, and medial canthus of the eye

Back 52

Habronema sp

Front 53

Wounds increase in size and do not respond to treatment until the following winter, when they spontaneously heal

Back 53

Habronema sp

Front 54

Diagnosis is based on biopsies and clinical signs

Back 54

Habronema sp

Front 55

Habronema sp

Back 55

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Front 56

Habronema sp

Back 56

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Front 57

Habronema sp

Back 57

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Front 58

Equine filarial parasite

Back 58

Onchocerca cervicalis

Front 59

Produce recurrent dermatitis

Back 59

Onchocerca cervicalis

Front 60

Periodic opthalmia

Back 60

Onchocerca cervicalis

Front 61

Adults live in the ligamentum nuchae (ligament that runs from the skull down the cervical spine)

Back 61

Onchocerca cervicalis

Front 62

Females produce microfilrariae that migrate to the dermis via connective tissues

Back 62

Onchocerca cervicalis

Front 63

Spread by biting midges

Back 63

Onchocerca cervicalis

Front 64

Cause cutaneous onchocerciasis
patchy alopecia and scaling on head, neck, shoulders and ventral midline, may be accompanied by intense puritis

Back 64

Onchocerca cervicalis

Front 65

Many horses are asymptomatic

Back 65

Onchocerca cervicalis

Front 66

Biopsy can be examined for microfilaria

Back 66

Onchocerca cervicalis

Front 67

Onchocerca cervicalis

Back 67

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Front 68

Lives within the conjunctival sac and on the surface of the eye

Back 68

Thelazia sp

Front 69

Remove while eye is anesthetized

Back 69

Thelazia sp

Front 70

Equine tapeworms

Back 70

Anoplocephala perfoliata and A. magna

Front 71

found in the SI, LI and cecum

Back 71

Anoplocephala perfoliata

Front 72

found in the SI and sometimes the stomach

Back 72

A. magna

Front 73

Proglottids are wider than long

Back 73

Anoplocephala perfoliata and A. magna

Front 74

has only one set of male and female reproductive organs in each proglottid
Eggs are thick walled with one or more flattened sides

Back 74

Anoplocephala perfoliata

Front 75

Grain mites are the intermediate host

Back 75

Anoplocephala perfoliata and A. magna

Front 76

Anoplocephala sp.

Back 76

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Front 77

Anoplocephala sp.

Back 77

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Front 78

Anoplocephala perfoliata

Back 78

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Front 79

Anoplocephala perfoliata

Back 79

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