Nematodes Part II

Eggs, part of larvae and empty shell of Dictyocaulus arnfeldi. Lungworms of horses

• Dictyocaulus filaria
• Lungworm of sheep, goats and deer

• Strongyloides papillosus
• Intestinal threadworm of cattle, sheep and swine.

Metastrongylus apri - Lungworms of pigs

• Strongyloides stercoralis
• Intestinal threadworm of dogs, foxes, cats and man

Strongyloides larvae normally appear in freash feces of infected dogs - eggs are not usually seen.

Strongyloides stercoralis X400

• A = Strongyloides westeri
• B = Strongyles sp. X100

Strongyloides westeri - eggs are embryonated when laid

• Strongyloides papillosus X100
• "Intestinal threadworm" of cattle, sheep, goats and rabbits.

Strongyloides papillosus - eggs are embryonated when laid

• Spirocerca lupi
• Esophageal worm of dogs and foxes

Spirocerca lupi eggs X400

Spirocerca nodules in the lumen of the esophagus. Adult worms are seen in the granulomous lesions.

Sarcoma in the esophagus due to Spirocerca sp.

Opened esophagus of a dog with 3 distinct nodules produced by Spirocerca sp.

• Spirocerca eggs
• A= low power B= high power

Spirocerca lupi eggs containing fully formed larva. 

Spirocerca lupi

• Pearsonema plica
• Urinary bladder; feces

Pearsonema plica eggs X400

• Dioctophyma renale
• Giant worm of dogs, foxes and occasionally man
• Found in urinary sediment; may be found in feces contaminated with urine

Eggs of Dioctophyma renale

• Eggs of Stephanurus dentatus
• Kidney worm of swine
• Eggs are found in urinary sediment and occasionally in feces.

Eggs of Stephanurus dentatus X400

• Eggs of Physaloptera praeputialis
• Stomach worm of cats, dogs, foxes and wild felidae.

Eggs of Physaloptera praeputialis X400

• Physaloptera rara
• Stomach worm that contains an embryo when passed in the feces

• Eggs of Habronema muscae
• Gastric nematode of horses

Habronema muscae

Eggs of Draschia megastoma. Eggs are from exudate in a gastric abscess, which contains adult worms.

• Draschia megastoma - horse
• Seen are larvae in the feces

Chronic gastritis in a horse with numerous ulcers associated with Trichostrongylus axei

Inflammation and catarrhal (pus) in the stomach caused by Trichostrongylus axei

• Gasterophilus intestinalis in the stomach
• Gasterophilus nasalis in the duodenum

Submandibular edema "bottle jaw" in cow with parasitic gastritis

• Eggs from Haemonchus sp
• Stomach worm of cattle, goats and sheep

• Eggs of Haemonchus contortus
• "Common or twisted" stomach worm of cattle, sheep and goats

Haemonchus sp worms on the mucosal surface. Female worms resemble a barber pole.

• Ascarops strongylina
• Stomach worm of swine

• Strongyles sp eggs
• Forty species have been reported from the large intestines of horse, asses and mules in North America.

• 2 diff Strongyles sp. eggs
• Strongylus vulgaris (left)
• Strongylus edentatus (right)

• Eggs of Oxyuris equi
• Rectal worm, Nocturnal worm and pinworm
• Found in the feces, but exam of anal scraping is a more accurate method of diagnosis.

• Oxyuris equi
• Single opeculated

• Nematodirus spathigier - largest egg
• Also called thread necked nematode of cattle, sheep and goats

Eggs of Nematodirus spathiger

• Eggs of Oesophagostomum sp.
• Nodular worm of swine

Eggs of Oesophagostomum sp.

• Eggs of Macracanthorhynchus hirudinaceus
• Cestode
• Thorny-headed worm of swine

• Eggs of Macracanthorhynchus hirudinaceus
• Embryo is surrounded by 3 shells

Eggs of Macracanthorhynchus hirudinaceus

• Dirofilaria immitis larvae (microfilaria) 
• 1st stage of Heartworm infection in dogs, foxes, coyotes, wolves and cats

Dirofilaria immitis larvae in blood

Dirofilaria immitis. Larvae is straight because blood hemolyzed in 2% acetic acid.

• Metastrongylus apri
• Metastongylus salmi
• Metastrongylus pudendodectus
• Metastrongylus elongates

Dictyocaulus arnfeldi

Dictyocaulus filaria

Strongyloides papillosus

Strongyloides stercoralis

Strongyloides westeri

Spirocerca lupi

Dioctophyma renale

Stephanurus dentatus

Physaloptera praeputialis

Habronema muscae

• Haemonchus placei
• Ostertagia ostertagi
• Trichostrongylus axei
• Haemonchus contortus

Haemonchus contortus

• Ascarops strongylina
• Hyostrongylus rubidus (red stomach worm)
• Physocephalus sexalatus

Oxyuris equi

Nematodirus spathiger

• Oesophagostomum dentatum
• Oesophagastomum georgianum
• Oesophagastomum brevicauderm

Macracanthorhynchus hirudinaceus

Aneurysm of the cranial mesenteric artery from 4th stage larvae of Strongylus vulgaris

Hemorrhagic inflammation & necrosis of the cecum and ventral colon 2-3 weeks after infection with Strongylus vulgaris

Gastrophilus intestinalis on hairs of forelimb at the knee

• 2nd stage of Gasterophilus intestinalis
• Migration = hairs of the knee, then to the tongue, then to the stomach

Onchocerca cervicalis

Segments of ligamentum nuchae from lesions of Onchocerca cervicalis

Large lesions of Draschia megastoma in the stomach wall of a horse

• Spirocerca lupi
• Draschia megastoma

• Cutaneous habronemiasis
• AKA summer sores - stomach worm

Trichostrongylus axei eggs

Thelazia lacrymalis (eyeworms) along the border of the nicitanation membrane.

Typical stance of piperazine toxicosis syndrome

• Helminth eggs - feces of cattle
• Trichostrongylus axei
• Trichuris ovis
• Nematodirus spathiger

Calf with ostertagiasis with submandibular edema (bottle jaw/anasarca) caused by stomach worm that causes emaciation & diarrhea.

Marshallagia marshalli