trichostrongyle herbivores Exam 2 (L13-15)

Which family of nematodes has the most important causes of production and economic loss in livestock

trichostrongyle nematode

Why are trichostrongyle nematodes of ruminants the most important causes of production and economic loss in livestock (general question)

• lamb, calf deaths

• poor growth rate

• tx and management cost

Where does conversion of trichostrongyle egg to L3 occur

Only occurs in pasture where animals are actively grazing

In transmission of ruminant trichostrongyle, what are two ways that they do not transmit dz in relation to environment

1. do not transmit in confined situations (→ no transmission of ruminant trichostrongyle parasites)

2. not transmitted to young ruminants bc they are nursing

At what age, must you start being concerned about host and management system in beef calves and sheep/goats

• in beef calves around 3-4 months of age

• in sheep/goats around 2-3 months of age

In sheep/goats, what 3 GI trichostrongyle nematodes genera cause dz syndrome of ruminants

• Haemonchus spp.

• Teladorsagia spp.

• Trichostrongylus spp.

In cattle, what 3 GI trichostrongyle nematodes genera cause dz syndrome of ruminants

• Haemonchus spp.

• Ostertagia spp.

• Cooperia spp.

Which larvae stage is the infective stage of trichostrongyle nematodes life cycle

L3 larvae

Which gastrointestinal trichostrongyle nematodes has specific seasonal patterns

H. Teladorsagia and H. Trichostrongylus

What occurs with immune response between Teladorsagia and Trichostrongylus

abomasum immune response to Teladorsagia affects proximal SI environment → establishment of Trichostrongylus in autumn

What are the hallmark dz of GI trichostrongyle nematodes

anorexia with diarrhea

What are CS of GI trichostrongyle nematodes (besides the hallmark CS)

• anorexia w diarrhea (hallmark)

• submandibular edema - bottle jaw

• hyporproteinemia

• dec well-being

• immune suppression

What type dx will GI trichostrongyle nematodes not show up (and why)

necrospy bc works are too small

What are the three methods of measuring FEC in GI trichostrongyle nematodes

1. McMaster

2. mini-FLOTAC

3. modified Wisconsin

What are the dx characteristics of using McMaster in measuring FEC in GI trichostrongyle nematodes

• quickest, easiest method

• method of choice for sheeps/goats; not sensitive enough for efficacy in cattle

• egg detection sensitivity usually 25 or 50 EPG

What are the dx characteristics of using mini-floatac in measuring FEC in GI trichostrongyle nematodes

• best method - highest accuracy and precision

• recommended method for cattle

• egg detection sensitivity is 5 EPG

What are the dx characteristics of using Modified Wisconsin in measuring FEC in GI trichostrongyle nematodes

• most time consuming method

• least accurat and precise

  • not recc

In dx of GI trichostrongyle nematodes, what method is most prefered for measuring FEC in cattle

Mini-floatac

In dx of GI trichostrongyle nematodes, what method is most prefered for measuring FEC in sheep/goat

McMaster

For administrating trichostrongyle nematode treatment, sheeps and goats should receive what type of administration method

oral only

For administrating trichostrongyle nematode treatment, cattle should receive what type of administration method

injectables (rather than pour-ons or oral ML)

In sheep and goats, what drug has the least resistance prevalence in Eastern US for trichostrongyle nematodes

levamisole

What are preventative methods if anthelmintics are ineffective in trichostrongyle nematodes

• sustainable integrated parasite management “sIPM”

  • improved pasture management

  • refugia management

  • “smart drenching”

  • novel non-chemical integrated approaches

  • biological control

What species is most affected by the Haemonchus spp., the predilection site, and common name

• most important worm of sheep/goats in USA

• abomasum is predilection site

• barber pole worm

What is the egg morphology of Heamonchus spp.

dark brown blastomeres in egg

What is the most important parasite of sheep/goats in warm climates

Haemonchus contortus

What species of Haemonchus infects cattle (and what regions does infection occur)

H. placei in subtropics and tropics

What is the PPP of Heamonchus

3-4 weeks

Why is the Heamonhcus spp. referred to as barber pole worm

blood-filled gut of females worms can spiral around their uterus giving a barber pole appearance

When does Haemonchus spp. develop from egg to L3 fastest

egg to L3 is faster in late summer as temp inc

When does egg to L3 stop seasonally in Haemonchus spp.

egg to L3 stops in autumn

What is the expected environment that you would find Haemonchus spp

• tropics OR warm, moist environments

  • cooler climates during summer

What occurs with Haemonchus spp. (and lifestage) to survive during too cold or too dry periods

L4 enter hypoitoic (arrested) state in host GI mucosa

What are common clinical features of Haemonchus spp. in sheep/goats vs Cattle

• sheep/goat: Haemonchosis - high blood loss

• cattle: clinical dz uncommon

What are CS of Haemonchus spp

• anemia

• submandibular edema - bottle jaw

• black tarry feces

• death

What CS would not be present in Haemonchus spp. which otherwise would be common in most GI trichostrongylus nematodes

no diarrhea

Amongst herd of cattle that are infected with Haemonchus spp. what does it mean when many animals appear normal while others are dying

an overdispersion of Haemonchus parasites

In severe cases of Haemonchosis, what would be the two CS

1. massive blood loss (untreated will lead to death bc of anemia; needs blood transfusion)

2. FEC are very high

During clinical exam, what are the dx of haemonchosis

• using FAMACHA card for anemia

• FEC supports dx

Which species of Haemonchosis is less resistant to anthelmintics

H. placei < H. contortus

What is the tx plan for Haemonchosis

• combination 2 or 3 anthelmentic drugs

• MUST test using FERCT

  • before and 2 weeks after tx

What is the most important parasite of adult cattle in USA

Ostertagia ostertagia (brown stomach worm)

What is the preferred environment for Ostertagia osteragia and predilection site

cool, wet climates

predilection site: abomasum

What is the egg characteristics of Ostertagia ostertagia

egg have dark brown numerous blastomeres 80-40micrometers (indistinguishable to Haemonchus)

What is the PPP of Ostertagia ostertagia

2 wks

What are the seasonal transmission characteristics of Ostertagia in warm temperate climates

• highest transmission in winter-spring

• larvae acquired in late spring become hypobiotic (arrested)

  • (to survive hot summers)

What are the seasonal transmission characteristics of Ostertagia in cool temperate climates

• highest transmission in summer-fall

• larvae acquired in late fall become hypobiotic

  • to survive too cold winter in host

What are the difference in grazing patterns of cattle in warm temperate climates vs cool temperate climates; and how does Ostertagia arrest depending on the climate

• warm temperate climates - freq grazing all-year; L4 stage arrest over summer

• cool temperate climates - seasonal grazing; L4 arrest over winter

What life stage does ostertagia arrest (hypobiosis) and why

early L4 stage arrest for 3-4 mo to avoid adverse environmental conditions

In warm temperate, the L4 stage of Ostertagia will arrest when

over the summertime in the host

In cool temperate, the L4 stage of Ostertagia will arrest when

over wintertime in host

What is the difference between clinical type I disease vs clinical type II disease of Ostertagia ostertagia

• Clinical type I - ingested of large number of L3 stages in summer

• Clinical type 2 - L4 develops and emerges as adult in late winter causing type 2 dz

In summer ostertagiosis, what is the primary lifecycle of Ostertagia ostertagia to develop clinical type I disease

as temp inc in summer, pasture larval contamination inc reaching infective L3 stage

In winter ostertagiosis, what is the primary lifecycle of Ostertagia ostertagia to develop clinical type II disease

as temp dec in winter, L3 becomes arrested at early L4 stage in abomasal mucosal glands

What is the primary pathology of ostertagia ostertagia

disruption of abomasal mucosa by development of larvae leading to gastric gland destruction

What is the post-mortem pathology of ostertagia ostertagia

• abomasum has putrid smell bc of bacterial overgrowth, high pH

• abomasum mucosa has nodules

• abomasum mucosa edematous and hyperemic

What are the Ostertagia clinical feature involving abomasal gastric glands

• larvae develop disrupting abomasal gastric glands

• high pH in abomasum due to replacement of HCL-secreting cells

What is the clinical feature of Ostertagia infection relating to pepsin

pepsin inhibits digestion of protein

What is the clinical feature of Ostertagia relating to albumin

albumin leakage thru abomasal mucosa

What is the tx of Ostertagiosis

ML is drug of choice

What species is infected by Teladorasagia circumincinta (and its predilection site)

sheeps/goats in abomasum

What is the egg characteristics of teladorsagia circumcinta

reddish-brwon w numerous blastomeres (~80-40micrometers)

What is the PPP of Teladorsagia circumcinta

2 wks

What causes loss of weight and appetite in Teladorsagosis dz (caused by T. circumcinta infection)

hyperplastic inflammation of abomasal mucosa (abomasitis)

What causes hypoprotinaemia in Teladorsagosis dz (caused by T. circumcinta infection)

leakage across damaged mucosa

What causes loss of weight and appetite WITH watery diarrhea in Teladorsagosis dz (caused by T. circumcinta infection)

impaired abomasal func associated w alteration in pH

What is the appearance of abomsal mucosa of Teladorsagia infection

morocco leather apperance

What is the tx of teladorsagosis

Benzimidazole + ivermectin DOC

What are the six sustainable control programs of teladorsagosis

1. build up infection in host

2. farming system

3. seasonal appearance

4. pasture contamination

5. TST and refugia management

6. dx tests

What is the host and predilection site of trichostrongylus axei

hosts: cattle, small ruminants, horses, pigs

predilection site:

• abomasum - ruminants

• stomach - horses pig

What is the smallest trichostrongyle

T. axei

What trichostrongyle nematode has unique characteristic of cross-infection in mixed species grazing situation

Trichostrongylus axei

Trichostrongylus axei is not usually a _____ pathogen by itself and is part of the ruminant ____ complex

primary; PGE

What species does Nematodirus battus infect

sheep/goats

What species does Nematodirus helvetianus infect

cattle

What species does Nematodirus spathiger infect

cattle, sheep/goat

What is different in the life cycle and epidemiology of Nematodirus spp. compared to typical trichostrongyle life cycle

L3 develops w/in egg and then egg hatches

What is the largest SI trichostrongyle

Nematodirus spp.

What is the typical appearance of Nematodirus spp. (part of the SI trichostrongylus family)

• males have long, thin pronounced spicules

• white worms coiled around villi

What are the seasonal weather requirements for Nematodirus spp. to hatch

hatching of eggs requires a prolonged chill winter followed by hatching normally in spring

Which SI Trichostrongyle is considered a lamb-to-lamb dz

Nematodirus spp.

What are the temperature requirements for hatching releasing of L3 Nematodirus spp.

a cold exposure followed by daily temp above 10degrees Celsius

In Nematodirus battus, pathology can be severe due to the occurrence of _____ _________

heavy infection

What are the clinical features of Nematodirus spp.

• cotton wool-like bundle on intestinal mucosa

• acute onset diarrhea

• sudden death

• lethargy

• weight loss

• dehydration

What is the predilection site of Nematodirus spp.

SI mucosa

The SI Trichostrongylus — T. colubriformis & T. vitrinus — infects what spp.

ruminants and cattle (less important in cattle); the most important nematode in sheeps/goats

What are the typical CS of T. colubriformis & T. vitrinus

• diarrhea + weight loss

• Mucosal and villus hypertrophy

• protein leakage, electrolyte and mineral imbalance

• anorexia w dark scour

What SI Trichostrongylus is a predominant contributor to FEC in young calves

Cooperia spp.

What life stage of cattle are infected by Cooperia spp.

young calves; never a problem in adult cattle

What is the major clinical feature of Cooperia spp. as it relates to production

rarely produces clinical dz but causes significant production loss

In Cooperia spp. tx, what age do you treat calves

4-12 mo

What tx would adult cows need for Cooperia spp.

adults cows will not need tx for cooperia spp.

What is the tx strategy for Cooperia spp.

• Benzimidazoles + levamisole

• ML — ivermectin — is resisted

  • pour-ons are worthless

What is the LI strongyle of ruminants and cattle

Oesophagostomum spp.

What are the hosts of Oesophagostomum spp.

• cattle

• sheep/goats

• swine

What is the appearance of Oesophagostomum spp.

• stout white worms

• shallow buccal cavity

• cephalic vesicle

What is the predilection site of Cooperia spp.

SI

What is the predilection site of Oesophagostomum spp.

LI

What is the primary pathology of Oesophagostomum spp.

presence of larvae in nodules stimulating an inflammatory response interfering w intestinal motility and absorption

During post-mortem, what does Oesophagostomum spp. infection look like

• pus-filled nodules in LI

• stout white worms in LI