Nematodes Part 1 Flashcards
What 3 things are classification of animal nematodes based on
Male reproductive organs, shape of the mouth and biology
Physical characteristics of nematodes
Covered with a cuticle
Have both a mouth and an anus
High internal body pressure
Typically have males and females
What is the name for a morphology of tubes within tubes
Psuedocoel
What are the bursate nematodes of importance in veterinary medicine (and this class)
Trichostrongyloidea
Strongyloidea
Ancylostomatoidea
Metastrongyloidea
What do all bursate nematodes have in common
A copulatory bursa at their posterior end
Trichostrongyloidea Hosts (include site) Mouth shape Type of Life cycle Way to diagnose
GI tract of ruminants (and horses)
Small buccal cavity
Direct life cycle
See egg or larva in feces
Which group of nematodes can cause the bottle jaw symptom and diarrhea
Trichostrogyloides
Which genus of Trichostrongyloidea have larvae that are resistant to both freezing and drying out.
Trichostrongylus
Where (anatomically) does the life cycle of Trichostrongylus arrest
In mucosa of host
What is hypobiosis
When larvae go to sleep - arrest in development
What are animals infected with Trichostrongylus exhibiting watery green diarrhea predisposed to
Fly strike
Where is Trichostrongylus axei found
Abomasum of ruminants
Stomach of horses
Where is Trichostrongylus culubriformis found within the host
Small intestine
What stage larva enters the mucosa of the gut in Trichostrongylus
L3
What is the most important bovine parasite in the world? And where in the animal is it found
Ostertagia
In the abomasum
What is the complement of Ostertagia (found in cattle) in sheep
Teladorsagia
What do Ostertagia and Teladorsagia look like?
Type of life cycle
Where are larvae found
Reddish worms about 1 cm long
Direct life cycle
Larva in gastric glands - can arrest as fourth stage larvae
Describe type 1 and type 2 disease in Ostertagia and Teladorsagia
- Without hypobiosis, usually late summer, early fall, in calves and lambs
- With hypobiosis, late winter and early spring caused by synchronous emergence, in older animals
Clin signs and diagnosis for Ostertagia and Teladorsagia
Moroccan leather appearance of abomasum for diagnosis
Clin signs: watery diarrhea, appetite intact - no digestion - hypoproteinemia
Where is Haemonchus (adult) found
Abomasum of cattle and sheep
Type of Life cycle of Haemonchus
Direct
Characterize 3 forms of disease with Haemonchus infection
Hyperacute - new animals released on heavily contaminated pasture, disease before patience, no eggs seen
Acute - mainly in young animals, hypoproteinemia and submandibular edema, many adults, > 10,000 eggs
Chronic - most common, few worms, few eggs < 2000, unthrifty animal
Cooperia
Where is it found anatomically
Signs
Small intestine of ruminants
Not highly pathogenic, diarrhea, anorexia depressed growth
What does hyostrongylus cause
Ulcerative gastritis in pigs
Where do hyostrongylus larvae develop
On pasture
Where are adult Nematodirus found
Associated disease
Small intestine
Destruction of mucosal architecture with diarrhea
What is special about Nematodirus
Huge egg
Larva develop in egg shell
Have long spicules
Ollulanus tricuspis Distinguishing characteristic Where is it found in the host Clinical presentation Transmission
Very small Trichostrongyle
Live I stomach of cat
Chronic vomiting
Trans. From cat to cat in vomitus
Where do L3 Ollanus tricuspis develop
Third stage larva develop in stomach
Scientific name for lung-worm
Dictyocaulus viviparus
Hosts of different species of Dictyocaulus
D. Viviparous in cattle
D. Filaria in sheep
D. Arnfieldi in horses
Where are adult Dictyocaulus found
Trachea and bronchi
Usually only a problem in calves
Life cycle of Dictyocaulus
Female lay eggs, larvae hatch, go up respiratory tree, swallowed, passed in feces… After infection 3rd stage larva migrate to mesenteric Ln to molt to L4 then migrate to lungs
Disease in Dictyocaulus
Prepatent disease: bronchitis, possible emphazema
Patent disease: frothy white mucus in airways, parasitic pneumonia (aspirated eggs and larva into alveoli)
Morphology of strongyles
Bursate
Large buccal cavity with corona radiate and often large teeth at base
Characterize life cycle of large strongyles
Direct
L3 infective by ingestion
L3 resistant to desiccation and temp. extremes
Where are strongyes found
Cecum and colon, often in horse
Is Strongylus vulgaris a large or small Strongyle
Large
Where does L3 Strongylus vulgaris go to molt into L4
Cecum/colon
How does L4 Strongylus vulgaris migrate to the intestinal wall
Via blood vessels, arterioles and arteries
Where do L4 Strongylus vulgaris molt to immature adults
In nodules in large intestine mucosa
Which bursate nematode predisposes horses to aneurysms
Large Strongyle Strongylus vulgaris
What the of signs can cranial mesenteric artery derived emboli from migrating Strongylus vulgaris cause
Posterior paresis Infarction of kidneys Infarction of intestine Impaction Death
Strongylus edentatus life cycle
L3 burrow in wall of LIntestime and reach liver via portal veins Molt to L4 in liver Migrate through peritoneum back to LI Molt and penetrate intestinal lumen PPP 11 months
Is Strongylus edentatus a large or small Strongyle
Large.
Strongylus equinus
Large or small?
PPP
Disease
Large
9 mo
No natural disease
Major differences between large and small Strongyles
PPP much shorter in small
Small are non migratory in the host
They are physically smaller.
Small often do not cause disease even in large numbers
Scientific name for shall strongyles
Cyathostominae
Associated disease with small strongyles
Diarrhea with emergence of large numbers of larvae from bowel wall in late winter early spring
Hosts of the following species:
- Chabertia ovina
- Oesophagostomum radiatum
- Oesophagostomum columbianum
- Oesophagostomum venulosum
- Oesophagostomum dentanum
- Ruminants
- Cattle
- And 4. Sheep
- Pigs
Life cycle type of Chabertia and Oesophogostomum
Direct
Why are Chabertia and Oesophogostomum called nodular worm
Larvae encyst in SI and LI wall in large nodules
Stephanurus dentatus
Host
Site specific location in host
Transmission
Pig
Peri-renal fat
Strongylid egg passed in URINE
Life cycle of stephanuris dentatus
Direct or earthworm paratenic host
Larvae migrate in kidney liver peritoneum and muscles
Settle in kidney
PPP 9-16 mo
Effects of Stephanurus dentatus on pigs and farmers
Minimal dz - May die if migrate to spinal cord
Losses at slaughter
Where is Mammomonogamus laryngeus found
Trachea, larynx, nasal cavity of cattle buffalo goat sheep deer and people
Are hookworms bursate or no bursate
Bursate
Where do hook worms live
Small intestines
Ancyclostoma caninum life cycle
Eggs passed in feces
Larva develop in soil to L3 (infective)
Larva swallowed or skin penetration
With skin penetration larva migrate to lungs, coughed up and swallowed
With ingestion, remain in mucosa until adults
Transmission of Ancyclostoma caninum
Transmammary - arrested larvae
Paratenic hosts mice and rodents where larvae arrest.
Diseas associated with Ancyclostoma caninum
Peracute diseaae - transmammary infected puppies, anemia, prepatent
Acute dz - older dogs, large number of eggs present, anemia and tarry stool
Chronic dz - asymptomatic
Ancyclostoma tubaeforme hosts
Cats
How is transmission of Ancyclostoma tubaeforme different from Ancyclostoma caninum
No transmammary transmission
Zoonotic hookworm infections
Cutaneous larva migrans - A. Braziliensis usually
Large bowel disease - A. caninum
Hookworm species in ruminants and pigs
Bunostonum phlebotomum in cattle
B. Trigonocephalum in sheep and goats transmammary trans. Not important for either
Globocephalus in pigs, may have transmammary trans
Group for lungworms
Bursate or not
Metastrongyloidea
Bursate ( reduced in males)
Intermediate host for lungworms
Snail
Lungworms of pigs
Disease
Matastrongylus apri
Dz usually modest - pneumonia and parasitic bronchitis
Metastrongylus apri life cycle
Eggs coughed up and swallowed, contain L1 when passed in feces
Egg eaten by earthworm
Larva develops to L3
Pig eat earthworm and larvae penetrate intestine, enter lymphatic to head to heart then lungs
Lungworm of sheep
Protostrongylus
Protostrongylus life cycle
Eggs laid in lung, larva hatches Coughed up and swallowed Passed in feces Larva penetrates snail Host eats snail,while grazing larva enter lymphatics got to heart then lungs
Hair lungworm
Scientific name
Hosts
Muellerius capillaris
in lung parenchyma
Sheep, goats & deer
Parelaphostrongylus tenuis found where
Dz
Meningeal worm of white tailed deer, migrate through spinal cord
No diseases in deer, but posterior paralysis in many other species
What metastrongyle resides in the lung parenchyma of cats and dogs
Life cycle type
Transmission
Filaroides hirthi
Direct
Larva in sputum or feces
Metastrongyle in dog trachea and bronchi
Transmission
Crenosoma vulpis Ingest snail intermediate host Also Oslerus osleri (nodules) Direct life cycle first stage larva in feces
Where is adult Angiostrongylus vasorum found in host
Pulmonary arteries
Distinguishable feature of Angiostrongylus vasorum larvae
Kink In tip of tail
Life cycle key points of Angiostrongylus vasorum
Snail intermediate host, may have frog and rodent paratenic host
Clin signs of Angiostrongylus vasorum
Chronically, progressing pulmonary disease and cardiac failure - depression stunted growth weight loss coughing decreased activity dyspnea edema
Cause of canine neural angiostrongylosis
3 grades of disease
Angiostrongylus cantonensis
- Caudal paresis, ataxia, pain with deep pressure
- Progressed from 1 inability to stand or urinate
- Rapid ascending paralysis with extreme hyperalgesia (poor prognosis)
Feline lungworm
Where are adults found
Dz
Transmission
Aelurostrongylus abstrusus Bronchioles and alveolar ducts Bronchopneumonia Ingest vertebrate paratenic host, rarely eat snail intermediate host Tx with panacur
Troglostrongylus wilsoni
Where is adult found
Life cycle
Bronchi of cat
Indirect life cycle with mollusk intermediate host
Oslerus rostratus
Where are adults found
Dz
Lung parenchyma of cats
Chronic bronchitis and peribronchitis
Where is Gurltia paralysans found
Spinal cord in cats in Chile
