What causes bovine lungworm?
Dictyocaulus viviparus
Where is Dictyocaulus viviparus found?
found in the trachea and larger bronchi –> parasitic bronchitis (husk, hoose)
Other than cattle, what species can Dictyocaulus viviparus affect?
farmed deer
Outline immunity to bovine lungworm?
- minimal age resistance
What are the different stages of D. viviparus infection? 4
What happens in the penetration phase (bovine lungworm)?
Week 1 - larvae migrate to lungs, no CS
What happens in the pre-patent phase (bovine lungworm)?
Weeks 1-3
Development + migration of larvae –> bronchiolitis –> eosinphilic exudate –> blocks passage of air –> alveolar collapse distal to blockage –> CS (tachypnoea, dyspnoea)
What happens in the patent phase (bovine lungworm)?
Weeks 4-8
Worms mature and become egg-producing –> bronchitis (adult worms) and parasitic pneumonia (reaspiration of eggs as larvae –> cellular infiltration by polymorphs, macrophages, FB giant cells)
What happens in the post-patent phase (bovine lungworm)?
Weeks 8-12
Period at end of disease when most worms expelled, but CS flare up in 25% cases due to alveolar epithelialisation (alveolar cells replaced by cuboidal cells), interstitial emphysema, pulmonary oedema and secondary bacterial infection
When can cows become reinfected with bovine lungworm?
Immune cows only show CS if exposed to massive challenge. Larvae reach lungs but killed by IR. Pathology: parasite granuloma (5mm, grey-green) and eosinophilic plugs in bronchioles)
How can a diagnosis of bovine lungworms be made in calves?
Features of lungworm larva? 3
Features of GIT larvae
Which larvae can be present in bovine faeces?
Lungworm only. GIT worms shed eggs so only if faecal sample is left unrefrigerated does it have larvae which hatch out of eggs.
how should you do a faecal exam for bovine lungworm?
examine healthy and sick animals - all positive samples are potentially significant - carrier animals possible (30% yearlings and 5% cows, also vaccinated cows)
Outline PME findings for bovine lungworm
How can you make a diagnosis of bovine lungworm in adult cattle? 7
Outline bovine lungowmr vaccination
Bovilis HUSKVAC
What is an anamestic response?
it is a second response to a vaccine (e.g. Bovilis HUSKVAC) where there is an exaggerated Ab response (especially compared to the 1st vaccine where there is a reasonable Ab response)
Outline the result of Huskvac vaccination - 3
Outline anthelmintic control of bovine lungworm
Name 3 ovine lungworm species
- Muellerius and Protostrongylus
Outline Dictyocaulus filaria LC
- PPP 5 weeks (longer than D.viviparus)
Outlien Muellerius and Protostrongylus LC