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What are the two main families of lungworm in ruminants?
Trichostrongyloidea and Metastronglyoidea
Does trichostronglyoidea have a direct/indirect lifecycle?
Why family (trichostronglyoidea or metastrongyloidea) is pathogenic?
Does metastronglyoidea have a direct/indirect lifecycle?
What disease does trichostronglyoidea lungworms cause?
Parasitic bronchitis (husk)
What are the different trichostrongyloidea species for the following animals? a) Cattle b) Horse and donkey c) sheep and goats e) deer and other cervids?
- a) Dictyocaulus viviparus b) Dictyocaulus arnfieldic) Dictyocaulus filaria
- d) Dictyocaulus eckerti
Describe the lifecycle of Dictyocaulus viviparus
- L1 is excreted in faeces --> L2 --> Infective L3 on pasture ingested and penetrate intestinal mucosa (Pilobolus fungus aids dispersal of L3s) --> L4 in mesenteric lymph nodes --> Lymphovascular route to lungs --> young adults in bronchioles and small bronchi --> Adult worms in main stem bronchi/trachea --> Eggs hatch in lungs and L1 migrate up to trachea and swallowed
- PPP = 26 days
How do animals develop good natural immunity to Dictyocaulus viviparus?
Cattle gain strong immunity following infection (it only takes one infection for cattle to become immune)
What are the clinical signs of Parasitic bronchitis?
- Mildly affected animals - intermittent cough
- Moderately affected animals - coughing at rest, tachypnoea (deeper breathing rate), hyperpnoea (deeper breathing)
- Severely affected animals - harsh cough, tachypnoea, dyspnoea, mouth breathing
Describe the prevention of lungworm
- Vaccination with irradiated L3 vaccine, vaccinate 1st season calves before turnout
- Oral vaccine - bolus huskvac. Very effective but cannot mix vaccinated and unvaccinated calves.
- Immunity is boosted by infection
- Prophylactic use of anthelmintics
Describe the treatment of lungworm
- All - anthelmintic drugs
- Mildly infected animals - treat and move to clean pasture
- Severely affected animals - house, hydration, NSAIDs, antibiotics if pyrexic
How does the lifecycle of Dictyocaulus arnfieldi differ from Dictyocaulus viviparus?
They have the same lifecycle except eggs are excreted in faeces with D. arnfieldi not L1s.
What is the PPP for Dictyocaulus arnfieldi?
True or false: Dictyocaulus arnfieldi reaches patency in adult horses?
False- adult horses block the infection from completing its life cycle. You will not see eggs in the faeces of adult horses.
What is the PPP of Dictyocaulus filaria?