DL: parasitic bronchitis

Question 1

What do you need to consider when deciding which anthelmintic is best for a disease outbreak of bovine lungworm?

Answer 1

• efficacy against different stages of D. viviparus
• dairy cow stage of lactation (eprinomectin has no milk withdrawal time but is 3-4 time more expensive than Fenbendazole). Consider number of animals to be treated, stage of lactation, milj quota and if it has been reached, farmer reliability.

Question 2

Prognosis of D.viviparus infection

Answer 2

• Early stage - goo
• Late stage (large worm burden) - marked loss of production, death, deterioration may be rapid with tx as dead and young worms can be reaspirated back down respiratory tree)

Question 3

How could you manage a clinical outbreak of D.viviparus?

Answer 3

• move to safe pasture
  (e. g. sheep pasture or newly seeded pasture or grazed by cattle vaccinated earlier that years)
• NSAIDs (reduce severity of host reaction to parasite)
• ABs (prophylactic)

Question 4

What control strategies are available for controlling husk in low risk areas of the control? 2

Answer 4

• control strategies (e.g. vaccination) would not be necessary and would certainly not cost effective
• anthelmintic treatment of
o newly-purchased animals (to prevent introduction of infection onto the farm if purchased from an area where lungworm is endemic)
o clinical cases ( individual basis)

Question 5

What control strategies are available for controlling husk in areas with previous history of husk? 3

Answer 5

• introduce vaccination (if not already practised)
• vaccinate newly-purchased animals prior to turn out
• anthelmintic treatment (modern drug, prolonged residual activity against lungworm) if insufficient time to vaccinate newly-purchased animals (of unknown vaccination status)

Question 6

What control strategies are available for controlling husk in areas with a recent disease outbreak I.e. partly through a grazing season)? 3

Answer 6

• anthelmintic treatment (modern drug, prolonged residual activity against lungworm to protect animals for the remainder of the grazing season)
• introduce vaccination next grazing season (if not already practised)

Question 7

Why might clinical lungworm disease be getting more common in adult dairy cattle? 3

Answer 7

• reduced vaccination of calves
  • Cost of vaccination of calves - reduces starting calfhood vaccination and continuing vaccination
  • Cheaper alternative control methods, e.g. strategic anthelmintic tx BUT animals are unlikely to be immune to lungworm at the end of the grazing season
  • Changes in pasture management practices, e.g. adult cows put onto calf pasture, increased stocking density

Question 8

How much does a Huskvac vaccine cost?

Answer 8

Approximately £10 per calf for 2 doses in 2015

Question 9

How much does anthelmintic treatment of a 150kg calf cost? (5 anthelmintic drugs)

Answer 9

o	Levamisole (Levacide 7.5%).  Price /L: £25, dose: 1ml/10kg, £0.40/dose
o	Fenbendazole (Panacur). Price/L: £65, dose: 1ml/13kg, £0.75/dose
o	Ivermectin (Ivomec) Price/L: £40, dose: 1ml/10kg, £0.60/dose
o	Doramectin (Dectomax) Price/L: £94, dose: 1ml/10kg, £1.41/dose
o	Eprinomectin (Eprinex) Price/L: £115, dose: 1ml/10kg, £1.73/dose