Parasitology lab: Nematodes 2: 1-35

Dirofilaria immitis larvae (microfilaria)

Direct smear slide

Large strongyles 

Mucosa of large intestines illustrating natural infection of adult blood sucking

Strongyle egg in fecal float

Infective larvae (L3 stage) of strongyles

Yearling horse in poor condition as result of chronic infections of parasites and malnutrition

Left to right: Ascarids, large strongyles, small strongyles, pin worms and tapeworms comparing size and gross morphology

Strongylus vulgaris

Aneurysm of cranial mesenteric artery

S. vulgaris larvae (L3 infective stage)

Hemorrhagic inflammation and necrosis of cecum and ventral colon of a foal

Strongylus edentatus 

Enlargement of cecal veins and perivascular tissues via the portal circulation to the liver

Parascaris equorum 

Small intestines which have perforated wall of mesenteric attachment

Oxyuris equi 

Common "pinworm" in horse

Oxyuris equi

"Pinworm" Horse

Parascaris equorum 

Horse

Ascarid egg in a fecal flotation preparation

Gasterophilus intestinalis 

"Common bot" on the hairs of the forelimb at the knee

Upper molars of a horse illustrating periodontal ulcers containign 1st and 2nd stages of Gasterophilus sp.

Second stage of Gasterophilus intestinalis "Common bot" at base of tongue

Dictyocaulus arnfieldi 

Lungworms in trachea of horse

Onchocerca cervicalis

Skin lesion in naval area 

Horse

Onchocerca cervicalis 

Segments of ligamentum nuchae

Draschia megastoma and Habronema muscae 

Specimens of stomach worms from horse

Draschia megastoma 

Stomach wall of a horse

Draschia megastoma 

In stomach wall of a horse

Cutaneous habronemiasis (summer sores) affecting penile sheath of a stallion

Cutaneous habronemiasis (summer sores) with lesions at the orifice of urethra

Trichostrongylus axei

"Minute stomach worm"

Trichostrongylus axei

"Minute stomach worm"

Thelazia lacrymalis 

Eyeworm on the eye of a horse along the border of the nicitanation membrane

Strongyloides westeri 

Horse

Weanling foal exhibiting typical stance of piperazine toxicosis syndrome

Helminth

Cattle

Beef cattle showing signs of clinical parasitism as reflected in diarrhea and poor condition

Calf with ostertagiasis

Note: Bottle jaw, emaciation and diarrhea

Dissection of lungs is helpful post-mortem to diagnose lungworms.

Dictyocaulus viviparous 

In the air passages