Nematodes Large Animal Flashcards
Which nematodes effect the GI system in large animals?
Trichostrongyles spp
Oxyuris equi
Trichinella spiralis
Which nematodes effect the circulatory system in large animals?
Strongylus viulgaris
Which nematodes effect the respiratory system in large animals?
Dictyocaulus spp
Which nematodes effect the integumentary system in large animals?
Onchocerca cervicalis
What are the hosts for Trichostrongyles?
Cattle, sheep, goats
Where in the body does Trichostrongyles effect?
Abomasum in cattle
Large & small intestine
How do you diagnose Trichostrongyles?
Fecal float for eggs
Fecal culture for larval identification
What is the lifecycle of Trichostrongyles?
Eggs are passed in feces and hatch into free living larva. Matures to 3rd stage where it becomes infective. Climbs onto grass and is ingested when animal is eating grass. Matures to adult in intestines
What are the clinical symptoms of Trichostrongyles?
Bottle jaw, anemia, weakness, diarrhea, sudden death
Which nematode is known as the”equine pinworm”?
Oxyuris equi
Where in the body does Oxyuris equi effect and what does it cause?
Lives in cecum, colon, & rectum. Causes pruritis (horse scratching rear end) and tail hairs being broken
How can you identify Oxyuris equi?
Tape impressions, anal scraping, fecal floatation
T/F only female pinworms can deposit eggs on horses
True. Only female pinworms can deposit eggs on the anus
What are the hosts of Trichinella spiralis?
Definitive & intermediate: pig
Abberant: humans
Where is the body does Trichinella spiralis effect?
Definitive host in the small intestine
Muscle tissue in the intermediate host
How do you diagnose Trichinella spiralis?
Eggs and larva are seldom recovered. Muscle biopsy or serology
What are the clinical signs of Trichinella spiralis?
Sometimes asymptomatic
Muscle damage
What is the lifecycle of Trichinella spiralis?
Females give live birth (viviparous). Larva penetrate mucosa and enter blood, then enter skeletal muscle where they encyst. Able to stay alive while encysted for long periods of time, then they die and calcify. If they don’t die they become infective larva. Meat is ingested and larva enters epithelial cells
What is the zoonotic potential of Trichinella spiralis?
Undercooked pork or wild game
What is the circulatory nematode in large animals?
Strongylus vulgaris
Where is Strongylus vulgaris located in the body?
Blood vessels of the large intestine. Migrate to cranial mesenteric artery
What are the clinical symptoms of Strongylus vulgaris?
They cut off blood supply to the intestines. Weight loss, colic, poor appetite, lethargy
How do you diagnose Strongylus vulgaris?
Fecal floatation
What is the lifecycle of Strongylus vulgaris?
Adults in large intestine lay eggs. Eggs are passed in feces and develop into L3 infective larva on the grass. Larva stay in water drops and are suspended on grass, horse eats grass and ingests larva. Larva enters large intestine and mature to L4. Then penetrate mucosa and enter blood vessels. Mature to L5 before penetrating small intestine
What is the prepatent period of Strongylus vulgaris?
6-7 months
Which is the respiratory nematode in large animals and which animal does it effect?
Dictyocaulus arnfieldi. Effects equines
Where is Dictyocaulus arnfieldi in the body and what does it cause?
Bronchi & bronchioles. Causes persistent cough, airway obstruction, & increased respiratory rate
What is the diagnosis of Dictyocaulus arnfieldi?
Fecal floatation for eggs & larva
What is the lifecycle of Dictyocaulus arnfieldi?
Embryontated egg/larva is passed. Mature to infective L3 on grass where it is ingested by equine. Migrates from GI to the lungs where is matures to adults in the bronchi
What is the prepatent period of Dictyocaulus arnfieldi?
2-3 months
Which is called the integumentary nematode and which animal does it effect?
Onchocerca cervicalis. Horses
Which nematodes is the equine filarial worm?
Onchocerca cervicalis
Where does Onchocerca cervicalis effect?
Nuchal ligament in adults & microfilaria in the dermis
What are the hosts of Onchocerca cervicalis?
Definitive: horse
Intermediate: midges (flies)
What are the clinical signs of Onchocerca cervicalis?
Cutaneous: alopecia, scales, pruritis
Opthalmic: “moon blindness” blue cornea
How do you diagnose Onchocerca cervicalis?
Skin biopsy with saline prep
