Adult Nematode Morphology with image (strongylids) Flashcards
(68 cards)
Name the nematode…
Small, hair-like worms, (7 mm) w/o cephalic inflations (wings), and virtually no buccal capsule
Spicules are short, twisted, and pointed

Trichostrongylus sp.
- Abomasa worm and 1st 6 meters of the small intestine
- Ruminants, horses, and leporids (rabbit)
- High host specificity
- Commonly confused with Strongyloides and Cooperia
Name the nematode…
Less the 14 mm long
Brown worms in cattle
Short, broad buccal cavity
Short 2 or 3 pronged spicules
Female tail is annulated with a vulvar flap (cuticular expansion)

Ostertagia ostertagi
- Live in the abomasum
- Chronic abomasitis
- Watery diarrhea, anemia, hypoproteinemia
- Appetite remains intact
- Die from malnutrition
- Most important helminth parasite of cattle in the USA
Less the 14 mm long
Brown worms in ruminants
Short, broad buccal cavity
Short 2 or 3 pronged spicules
Female tail is annulated with a vulvar flap (cuticular expansion)

Teladorsagia spp.
- Abomasal worm of ruminants

Name the nematode…
Up to 30 mm in length
Buccal cavity has a lancet
Male has asymmetric dorsal ray in its bursa and short wedge-shaped spicules
Females have a prominent vulvar flap

Haemonchus contortus, H. similis, and H. placei (USA)
- Anemia
- Can remove 1/5 of circulating RBC volume in a lamb per day
- Non-fatal infection will lose 1/10 of blood volume per day
- Widespread edema and bottle jaw
- Still eating well
- Do not lose appreciable weight
- No diarrhea unless co-infected with another intestinal parasite
Pigs and ruminants
Up to 30 mm in length
Buccal cavity has a lancet
Male has asymmetric dorsal ray in its bursa and short wedge-shaped spicules. Spicules are long and thin
Females have a prominent vulvar flap and close to anus

Mecistocirrus sp.
- Haemonchus contortus of pigs and ruminants in Central America, India, and Far East
Name the nematode…
Less than 9 mm long
Small intestine
Cuticle of the mouth is striated and slightly inflated
Buccal cavity is small
Spicules are shorts and blunted
Bursa- dorsal ray is lyre-shaped (harp)

Copperia oncophora- confused with Trichostrongylus and Strongyloides
Cooperia punctata
Most prevalent parasite in USA in cow/calf operations
Most infection asymptomatic
Name the nematode…
- 25m in length (similar size to Haemonchus)
- Cuticle of the mouth is striated like Cooperia
- Has a dorsal triangular tooth
- Neck is usually coiled
- Spicules are long and thin
- Uterus has very large eggs
- Female has a spine at the tip of her tail

Nematodirus spathiger, N. filicollis, N. battus, and N. helvetianus (USA)
- The dorsal triangular tooth differentiates it from Cooperia
- Nematodirus battus-Very restricted seasonal terrible diarrhea in lambs
Name the nematode…
- Stomach parasite of pig, dog, cat (domestic and wild)
- <1 mm, detected on biopsy
- Chronic gastritis
- Ovoviviparous
- Autoinfection from ingestion of larvae in vomit

Ollulanus tricuspis
- Chronic gastritis in cats

Name the nematode…
- 80 mm, white worms of ruminants and horses
- Buccal cavity is small
- Bursa is reduced
- Spicules are short, dark, and granular
- Vulva is near the middle of the body
- Eggs contain first stage larvae when laid (vermiform embryo), but usually hatches before it is eliminated in the feces

Dictyocaulus viviparous (cattle)
Dictyocaulus filaria (sheep)
Dictiocaulus arnfeldi (equids)
- Respiratory tract nematodes
Equine

Strongylus vulgaris
Equine

Strongylus equinus
Equine

Strongylus edentatus
Equine

Triodontophorus brevicala
(Large strongyle)
Equine

Tridontophorus serratus
(Large strongyle)
Equine

Oesophagodontus robustus
(Large strongyle)
Equine

Tridontophorus nipponicus
(Large strongyle)
Equine

Tridontophorus tenuicollis
(Large strongyle)
Equine

Gyalocephalus capitatus
(Large strongyle)
Equine

Coronocyclus coronatum
(Cyanthostominae)
Equine

Cyathostomum catinatum
(Cyanthostominae)

Equine

Cyanthostomum tetracanthum
(Cyanthostominae)

Equine

Coronocyclus labiatus
(Cyanthostominae)

Equine

Coronocyclus labratus
(Cyanthostiminae)

Equine

Cylicostephanus goldi

























































