10 terms

Nematodes - Strongylida - Trichostrongyloidea

Trichostrongyloidea - Lungworm
Dictyocaulus arnfieldi (lungworm)
Host: Donkeys
Adults: Long, white, 8cm
Eggs: Delicate, 75um L from fresh feces & bronchial washings; L1 400um L
LC: Direct, egg w/L1 in bronchi, develop to L3, migrate on pasture and ingested. L3 penetrate mucosa of si, enter lymphatics & blood, migrate to lungs.
PPP: 2-4mo
SOI: Bronchi of lungs
Path: Raised circumscribed areas of over-inflated pulmonary tissue in caudal lung lobes.
CS: None
Dx: L1 and eggs from fresh feces and lung washings via Baermann, eosinophils in tracheal mucus, adults necropsy, bronchi alveolar lavage (BAL) used to recover eggs and larvae.
Ostertagia ostertagi
AKA..Brown stomach worm
Adults: Slender, reddish-brown, 1cm, spicules in males and vulva in females
Eggs: Delicate, 85um L, thin shelled, outer surface of shell smooth, containing a morula
LC: Direct, egg w/L1 under optimal conditions develops in fecal pat to L3 in 2 wk, (moist) migrate on to herbage, L3 ingested during grazing, may arrest.
PPP: 21d
SOI: abomasum
Path: growth & leaving cause pathogenesis, reduction in function of gastric gland mass, distended gastric gland, thickened hyperplastic gastric mucosa, "moroccan leather", edematous abomasal folds, necrosis, hypoalbuminemai, submandibular edema, inappetance, wieght loss, diarrhea, leakage of endogenous protein into the gi.
CS: Type 1 Summer ostertagiosis - calves during 1st grazing season July to September, high morbidity; Type 2 Winter ostertagiosis - yealings in late winter or spring, hypoalbuminemia; profuse watery diarrhea, anorexia, weight loss 20%, poor coats, hindquarters soiled with feces common to both
Dx: clinical signs, seasonality, grazing history, fecal egg counts - type 1 (slow accumulation), type 2 negative due to arrested development, plasma pepsinogen levels, necropsy
Tx: Type1 - anthelmintics, moved to pasture not grazed by cattle; Type2 - anthelmintics for all forms, alternate grazing field; anthelminthic resistance to fenbendazole and morantel
Haemonchus placei
aka...Barber pole worm, wireworm
Host: Bovine
Adults: large 2-3cm, white ovaries wind spirally around the blood-filled intestine, male barbed spicules, vulvar flap, cervical papillae, lacent inside buccal capsule
Eggs: Delicate, 85um L, thin shelled, outer surface of shell smooth, containing a morula
LC: Direct, egg w/L1 under optimal conditions develops in fecal pat to L3 in 2 wk, (moist) migrate on to herbage, L3 ingested during grazing, may undergo hypobiosis in winter.
PPP: 23-28d
SOI: abomasum
Path: acute hemorrhagic anemia; acute haemonchosis - progressive fall in packed red cell volume and loss of iron and protein; chronic haemonchosis - takes place on a pasture devoid of nutrients, weight loss, weakness, inappetence
CS: hemorrhagic gastritis, anemia, edema, submandibular edema, ascites, diarrhea
Dx: clinical signs, fecal worm egg counts, trichostrongyloid L3, necropsy
Tx: anthelmintics and management; resistance to benzimidazoles
Cooperia spp
Host: Bovine, sheep, goats
Adults:<9mm, bursate
Eggs: typical trichostrongyloid, oval, 85um, thin shelled, outer surface smooth, morula
LC: direct, egg-l1,l2,l3 - consumed - l4
PPP: 15-18D
SOI: small intestine
Path: mild common pathogens in calves
CS: watery diarrhea
Dx: fecal egg counts, trichostrongyloid L3, necropsy
Tx: environment and animal husbandry, anthelminthic resistance to MCL & benximidazoles
Dictyocaulus viviparus
Host: Bovine
Adults: 3-10cm
Eggs: typical trichostrongyloid, oval, 85um, thin shelled, outer surface smooth
LC: Direct, egg w/L1 coughted up and passed in the feces; L3 infective; L3 pick up sporangia of the fungus Pilobolus spp.; L3 penetrate intestinal mucosa reach lung by way of lymphatic and bv's, breath through capillaries in lung and mature as adults in the trachea and bronchi.
PPP: 24+d
SOI: trachea and bronchi
Path - Penetration (1-7d): no cs apparent.
Path - PPP (8-24d): cellular infiltrates, alveolitis and brochiolitis.
Path - PP (25-60d): parasitic bronchitis, parasitic pneumonia, edema, emphysema
Path -PoPP (61-90d): lengthy recovery, relapses are fatal due to alveolar epithelialization of entire lung lobes.
CS: frequent bouts of coughing at ret, squeaks and crackles over posterior lung lobes, "air-hunger" position of open mouth breathing, postpatent parasitic bronchitis
Dx: clinical signs, hx, enedmic area, L1 via Baermann, necropsy
Tx: appropriate anthelmintics and management; anthelmintic prophylactic, vaccine (europe)
Teladorsagia circumcincta
brown stomach worm
Host: Sm Ruminant - sheep & goats
Adults: slender, reddish-brown 1cm long on abomasal mucosa
Eggs: oval, 85um, thin shelled, outer surface of shell smooth, containing a morula
LC: direct, L3 infective, adult 18d @ lumen of abomasal gland. Arrested development (@L4) may occur in intestinal wall ~6mo.
SOI: abomasum
PATH: similar lesions, but less severe clinical signs than with bovine ostertagiosis; Moroccan leather
CS: marked weight loss, diarrhea, inappetitence, periparturient rise or spring rise (PPR)
- increase in nematode eggs around parturition
- temporary relaxation in immunity with elevation in prolactin
- PPR drops when lactation ceases
PPR source:
1. maturation of arrested larvae due to host immunity
2. an increase establishment of infections acquired from the pastures
3. an increased fecundity of existing adult worm population
Dx: clinical signs, seasonality, fecal egg counts and L3 ID, necrospsy examination, plasma pepsinogen levels are above the normal
Haemonchus contortus
Barber Pole Worm
Host: Sheep and goats
adults: 2-3cm white ovaries wind spirally around the blood-filled intestine producing a "barber pole" appearance
Eggs: oval, 85um, thin shelled, outer surface of she'll smooth, containing a morula
LC: direct. eggs pass in the feces, develop to L3, migrate, ingested by FH, may hyperbiosis and encrypt in gut wall overwinter
SOI: abomasum
Path: acute hemorrhagic, anemia, hyperacute haemonchosis, chronic harmonchosis
CS: hemorrhagic gastritis, anemia, submandibular edema ("bottle jaw"), progressive weight loss and weakness
Dx: season, history, clinical signs, fecal worm egg counts, trichostrongyloid L3, necropsy, PPR
Nematodirus spp
long neck bankrupt worm
Host: sheep and goats
Adults: large, 2.5cm, spine on tip of tail, thin, twisted Nematodes look like cotton
Egg: v. large, 130um, 2-8 distinctive large cells inside egg
LC: direct. develops to L3 inside egg, emerge, ingested, L3 infective. 3 features:
1- capacity of the free-living stages to survive for up to 2yr on pasture.
2- emergence of large numbers of L3 simultaneously
3-lamb-lamb disease
SOI: adults in SI
PATH: due to larval stages. disrupt intestinal mucosa, villus atrophy, exchange of fluids and nutrients is compromised, diarrhea, dehydration, enteritis in the ileum
CS: diarrhea, pd
Dx: clinical signs appear during the PPP, grazing history, clinical signs, and necropsy used.
Dictyocaulus filaria
Lung worm
Disease: Husk, Hoose (b/c of noise they make when they are trying to breathe - particularly cattle), Verminous pneumonia
Host: Sheep & goats (temperate climates)
Adults: slender white, 10 cm in lungs as clusters & clumps in trachea & bronchioles
LC: lay eggs in bronchi, hatch to L1, coughed up, pass in feces; develop to L3, migrate up herbage during grazing; L3 penetrate intestinal mucosa, migrate to lungs, mature to adults in trachea and bronchi
PPP: 5 weks
SOI: Adults in lungs (bronchioles & trachea)
PATH: widespread lesion associated with bovine infection is not common in sheep and goats. In severe cases, pulmonary edema & emphysema may occur and the lung surface may be studded with purulent areas of secondary infection.
CS: coughing & unthriftiness, confined to young animals. Normally a chronic syndrome.
Dx: goats more susceptible than sheep. CS, Hx, endemic area, ID of L1 recovered with Baermann, necropsy
Hyostrongylus spp
stomach worm
Host: Pigs
Adults: slender reddish nematodes, 5-8mm
Eggs: oval, 85um, thin shelled, outer surface of shell smooth, containing morula
LC: Egg develops to L3 w/in 1-2wk; pig ingests L3; L3 inhabits gastric glands, develops to L4 and emerges as young adults, develop to mature adults on mucosal surface and in the lumen of the stomach. Larvae may hypobiosis
SOI: Stomach
PATH: severe damage to gastric glands, reduced acidity/increased bascity, mucosal hyperplasia, nodule formation, hemorrhage
CS: inappetence, loss of condition, anemia, no diarrhea
Dx: fecal and culture. eggs indistinguishable from Oesophagostomum spp.
Tx: outdoor pigs usually affected, "poor sow syndrome": infection with this nematode and/or nodular worm, anthelmintics that are effective against hypobiotic larvae, pasture management; timing of treatments as per Ostertagia spp.