Lecture 34 - Ostertagia Flashcards
what nematode causes disease in calves and young cattle
ostertagia
where are L4s in ostertagia
arrested in the lumen of gastric glands
describe acquired immunity to ostertagia
important for cattle
develops at approx. 2 years
mature cows will not show signs of infection
T/F: most ostertagia pathology is due to growth and development of L4s in the lumen of the gastric glands
TRUE
what are clinical signs of ostertagia
persistent watery D+
hypoproteinemia (bottle jaw and edema)
rough hair coat
stunted growth, weight loss
weakness
negative nitrogen balance results in
protein catabolism
how does ostertagia initiate clinical signs
decreases gastric acid so pH increases
what is apparent on necropsy of ostertagia infection
“moroccan leather”
inflamed papillae
is ostertagiasis seasonal? if so, when?
yes during grazing seasons
Describe Type I Ostertagiasis
L4 role
pathology
morbidity : mortality
treatment
L4s: develop directly to adult worms in young calves during 1st grazing season
pathology: summer & fall (cool regions) and winter & spring (arid regions)
high morbidity, low mortality (slow, progressive pathology)
tx: treat & move or treat & repeat
how does type II differ from type I ostertagiasis
early L4s arrest, and remain arrested for weeks to months whereas in type I L4s directly mature to L5s
Describe Type II Ostertagiasis
L4 role
pathology
morbidity : mortality
treatment
L4: arrest and reactivate later in yearling calves during 2nd grazing season
pathology: spring (cool region) and fall (arid region)
low morbidity, high mortality (acute pathology)
tx: treat older calves and target L4s
T/F: southern calves moved to northern feedlots in the fall have potential for type II ostertagiasis
TRUE
how is ostertagia diagnosed
- FEC
- MOO ELISA
- increased serum pepsinogen levels
- abomasal-centesis
- deworm & observe
- moroccan leather on necropsy
type I should be treated with ____ while type II should be treated with ____
adulticide; larvicide
T/F: there is reported resistance to dewormers for ostertagia in cattle
FALSE
what are the best pasture management techniques to avoid infective ostertagia L3s
- rotational grazing (naive calves first)
- co-grazing (cow/calf operations)
the pathology of trichostrongylus is due to
activity of adult worms
describe the life cycle of trichostrongylus spp.
- L3s over winter well on pasture, die off in summer, and recontaminate in fall
- L4s migrate below the mucosal surface but do not arrest
T. axei exist in the stomach of what animals
horse, rabbit, humans
what is caused by T. colubriformis
- damage to intestinal mucosa
- villus atrophy
- dark, watery D+ (fly strike complications)
- anorexia
how is T. colubriformis diagnosed
- clinical signs, history
- FEC
- larval speciation
what is the 5-point check in small ruminants
- FAMACHA
- Body condition score
- DAG score
- Nasal discharge
- Bottle Jaw
what are the deworming strategies for trichostrongylosis
- tactical - salvage deworming at clinical signs
- strategic - scheduled deworming
T/F: sheep/goats should not be co-grazed with horses to avoid T. axei infection
TRUE
what are L3 hatching requirements of nematodirus? what does this cause?
eggs must be chilled over winter before hatching
major larval storms
describe nematodirus
- pathology is due to adult activity and manifests as enteritis and severe D+
- large eggs
describe cooperia spp.
- pathology due to adult activity causing enteritis, D+, anorexia, emaciation
- prominent in cow-calf operations
- resistance to macrocyclic lactones
