Adult Nematode Morphology with image (strongylids) Flashcards
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
Equine
Cyincostephanus asymetricus
(Cyanthostominae)
Equine
Cylicostephanus bidentatus
(Cyanthostominae)
Equine
Craterostomum acuticaudatum
Equine
Cylicocyclus calicatus
(Cyanthostominae)
Equine
Cylicostephanus miniutus
(Cyanthostominae)
Equine
Cylicostephanus longibursatus
(Cyanthostominae)
Equine
Cylicocyclus nassatus
(Cyanthostominae)
Equine
Cylicocyclus ashworthi
(Cyanthostominae)
Equine
Cylicocyclus leptostomum
(Cyanthostominae)
Equine
Cylicocyclus elongatus
(Cyanthostominae)
Equine
Cylicocyclus ashworthi
(Cyanthostominae)
Equine
Cylicocyclus ultrajectinus
(Cyanthostominae)
Equine
Poteriostomum imparidentatum
(Cyanthostominae)
Equine
Poteriostomum ratzii
(Cyanthostominae)
Equine
Parapoteriostomum mettami
(Cyanthostominae)
Equine
Cylicodonotophorus bicoronatus
(Cyanthostominae)
Equine
Parapoteriostomum euprotus
(Cyanthostominae)
Equine
Cyanthostomum pateratum
Equine
Cylinocyclus auriculatus
(Cyanthostominae)
Equine
Petrovinema poculatum
(Cyanthostominae)
Equine
Cylicocyclus radiatus
(Cyanthostominae)
Equine
Cylicocyclus brevicapsulatus
(Cyanthostominae)
Large intestinal nematode of ruminants
Oesophagostomum columbianum
“Large intestine nodular worm”
Large intestinal nematode of ruminants
Charbertia ovina
“Nodular worms of large intestine”
Name the nematode…
- Kidney worm of swine
- Stout (2-40mm) parasite in the hepatic, renal, and perirenal tissues, axial musculature, and spinal canal of pigs and sometimes cattle
- Buccal cavity is cup-shaped with 6-10 triangular teeth at its base
- Gut is convoluted
- Spicules are equal and short
- Bursa is reduced
- IH: Earthworms (facultative) or direct by L3
Stephanurus dentatus
(Kidney worm of swine)
Small intestine of ruminants
Bunostomum spp.
Small intestinal nematode of dogs
Ancylostoma caninum
(Subfamily Ancylostomatinae)
Small intestinal nematode of dogs
Uncinaria stenocephala
(Subfamily Ancylostomatinae)
Small intestinal nematode of cats
Ancylostoma tubaeforme
(Subfamily Ancylostomatinae)
Small intestinal nematode of raccoons
Placoconus lotoris
(Subfamily Ancylostomatinae)
Describe the life cycle and clinical sign of peracute hookworm infection in the neonate
- Passage of L3 from dam to puppy during nursing
- Look good week one and then look like garbage on week 2
- Pale mucosa, soft to liquid diarrhea that is dark in color from blood
- Do not lay eggs until 16th day of infection
- May need to rely on coproantigen for detection
- Guarded to poor px
- Treatment
- Blood transfusion to keep puppies alive enough for drugs to kick in
- Administer anthelminthic at first signs of anemia
- Begin HWP in bitches as near birth as possible
- Treat with pyrantel until can begin labeled hookworm treatments
- Bitches can be treated with 50mg/kg of fenbendazole from day 40 of gestation to 14th day of lactation
Describe the life cycle and clinical signs of acute hookworm disease
- Occurs from sudden exposure of susceptible older ups to large numbers of infective larvae
- Many eggs are found in the feces
- Clinical signs precede eggs by 4 days
Describe the life cycle and clinical signs of chronic compensated hookworm disease
- No clinical signs
- Diagnosis is from the presence of hookworms eggs in feces and measurable reduction of RBCs count, Hb and PCV
Describe the life cycle and clinical signs with Secondary (decompensated) hookworm disease
- Older dogs
- Profound anemia is a malnourished or emaciated animal
- Hookworms are a secondary problem especially with malnutrition
- Anthelminthic require appropriate protein concentration
- Large white worms of the bronchi and bronchioles of swine
- Passed larvated eggs (L1)
- IH: Earthworms
- May not be an obligate IH
- Treatment
- Doramectin, ivermectin levamisole, fenbendazole
Metastrongylus spp.
- Lives in the smaller bronchioles of sheep and goats
- Males are brownish red and can be distinguished from D. filaria by longer comb-like spicules
- Treat: Fenbendazole
Protostrongylus rufescens
Tiny, embedded in the lung tissue or reactive nodules of sheep and goats
Diagnosed via L1 on Baermann
Treatment
Moxidectin inj (sheep)
Topical eprinomectin (goats)
Muellerius capillaris
- Well developed bursa with large dorsal ray
- Cuticle has lots of crenated folds (looks spiked or wrinkly)
- <16 mm long
- Found in the bronchioles and bronchi of foxes, wolves, raccoon, and dogs
Crenosoma vulpis
What is the life cycle and treatment of Alerostrongylus abstrusus?
Oviparious and deposit eggs in “nests” in the lung parenchyma of domestic cats
- Males have stout spicules
- L1 carried up the bronchial tree
- Find L1 at 5-6 weeks after infection; Baermann or ZincSO4
- IH: Snail and slugs (2-5 weeks to develop to L3)
- Paratenic host: Mice and birds
- Treatment-
- Ivermectin
- Fenbendazole
What is the life cycle of Angiostrongylus vasorum?
- L1 shed in feces and resemble A. abstrusus
- IH: wide range of molluskan
- After eating molluskan (L3) the larvae migrate to visceral lymph nodes
- Molt in LN and migrate to the lungs and pulmonary arteries
- PPP: 7 weeks
- Diagnostics: Baermann, fecal float, Ag and Ab ELISA, qPCR
What is the life cycle of Angiostrongylus cantonensis?
- L1 shed in the feces of rats and invade molluskan
- Rats eat L3 in IH and make their way to the brain of the rat
- Then molt and enter a vein to be carried to the heart and pulmonary arteries
- Paratenic host: crustaceans and amphibian
- Importance
- If humans ingest snails the worms migrate to the brain causing eosinophilic meningitis and encephalomyelitis
- IH: Giant African Snail (Achatina fulica)
- 1/4 of rats in Baton Rouge are infected
- Treatment:
- None
What is the life cycle of Angiostrongylus costaricensis?
Rodents in Central and South America
L1 in feces
IH: snails
Clinical signs in people for ingestion of L3 in snails
Lower right abdominal pain, fever, and vomiting
What is the life cycle and treatment of Filaroides osleri?
- Nodules in the trachea and bronchi
- Females deposit delicate eggs with L1 that hatch before being defecated out
- L1’s are directly infective and all 5 stages mature in the lungs
- Can detect nodules at 2month
- Find L1 with ZnSO4 at 6-7 months post-infection
- Successful treatment
- The disappearance of cough and air hunger with exercise
- Resolution of nodules on the scope
- No larvae in poop
- Treatment: fenbendazole, ivermectin, and doramectin
What is the life cycle and treatment of Filaroides hirthi?
- L1 is infective
- L1s arrive in the lungs 6 hours after oral ingestion and travel by way of hepatic portal circulation and mesenteric drainage or both
- Find L1 in fecal float 32-35 days post-infection
- Treatment
- 25 mg/kg albendazole x 5d
