NADIS

Welcome to NADIS. This map will only appear on the initial visit to the website. Please select your region, and you will be automatically be taken to your region on future visits

Northern Ireland North Scotland South East Scotland South West Scotland North East England Yorkshire & Humber East Midlands East of England South East England North West England Wales West Midlands South West England
Region:
Download this page as a PDF

Download now

NADIS Parasite Forecast - April

Use of meteorological data to predict the prevalence of parasitic diseases

 

PF Capture

It was a mild month with the UK mean temperature 5.2 °C, which is 1.5 °C above the 1981-2010 long-term average, and the number of air frosts among the lowest in the last 50 years. The UK overall received 184% of average rainfall, making it the 4th wettest February in the historical series. A broad region covering most of Wales and southern England received more than double the average rainfall for February, as did some other areas; a few places had close to three times the average. The region of south-east and central southern England, with 270% of normal, was only just short of its February rainfall record. It was not so wet everywhere though, and parts of Lincolnshire, north-east England and north-east Scotland received near average rainfall. There was a general division in sunshine across the country; despite being so wet the south-east of the UK was sunnier than average whereas some western areas were duller than average. The UK overall received 108% of average sunshine hours (www.nadis.org.uk).

April Parasite Forecast/Update

The most recent version of this monthly parasite forecast may be accessed at www.nadis.org.uk.

SHEEP NEMATODES

Control of PGE in adult sheep after lambing

  • Plan grazing and anthelmintic control policy now.
  • The aim of anthelmintic treatment of ewes around lambing time is to reduce pasture contamination and subsequent challenge to lambs.
  • Ewes grazing contaminated pastures may need a persistent anthelmintic treatment to prevent immediate re-infection from the pasture.  All sheep should be treated in these circumstances.
  • Rams appear more susceptible than ewes to PGE and should be included in the anthelmintic treatment plan.
Ewes turned out onto clean pasture only require a short acting anthelmintic treatment before turnout. Consider leaving ewes nursing single lambs untreated

Fig 1

Plan grazing and anthelmintic control policy now.

Fig 2

Ewes grazing contaminated pastures may need a persistent anthelmintic treatment around lambing to prevent immediate re-infection from the pasture.

Fig 3

Ewes turned out onto clean pasture only require a short acting anthelmintic treatment before turnout. Consider leaving ewes in good body condition nursing single lambs untreated.

NEMATODIRUS WATCH

Severe outbreaks of nematodirosis were encountered on many farms in May and June 2013.

  • Mean UK monthly temperatures from December 2013 to February 2014 have all been above the 1961-1990 monthly averages suggesting an early hatch of N. battus eggs present on contaminated pastures and a below-average risk of disease this spring.
  • However, March and April temperatures and rainfall can significantly alter this early season prediction and a more accurate forecast for overall incidence and peak hatch will be made in early April and will be included in the May parasite forecast.

Fig 4

Severe outbreaks of nematodirosis were encountered on many farms in May and June 2013.

Nematodirus control

The best control method is to graze lambs on pasture not grazed by lambs the previous year.

  • Where this is not possible, and March and April are mild allowing early hatching, then February and early March born lambs may need prophylactic anthelmintic drenching before the end of April.
  • Benzimidazole (Group 1) wormers are usually recommended for Nematodirus control.
  • When a BZ anthelmintic is used in outbreaks of nematodirosis, the faecal egg count of several lambs should be checked for significant Teladorsagia infection which, where present, would likely necessitate an anthelmintic from another class.
  • As disease is primarily caused by developing larvae, faecal egg-count monitoring to time Nematodirus treatments is too risky.

 

Fig 5

Excellent forward planning - nematodirosis should not be a problem on low risk pasture

Fig 6

No forward planning - nematodirosis affecting lambs during May 2013.

WATCH OUT FOR LIVER FLUKE

Sheep on premises with a known fluke population will already have been dosed in the autumn and early winter and should be dosed again in March/April. Newly diagnosed cases of chronic fluke disease (fluke eggs in faecal samples) can be treated with any available flukicides.

Triclabendazole should not be used in the spring because a high level of activity against immature flukes is not required.

WATCH OUT FOR COCCIDIOSIS

Coccidiosis is a significant risk in April, in February/March born lambs, or in older lambs when the feeding of medicated creep is stopped. It is a disease of intensive husbandry, and adverse weather conditions leading to poor colostrum supply, poor grass growth, wet muddy paddocks and/or extended housing periods can increase incidence.

Sheep must be moved from infected pastures/premises as soon as disease becomes apparent. The choice of medication will depend upon individual farm circumstances as prescribed by the veterinary practitioner.

Fig 7

Coccidiosis is a significant risk in April in February/March born lambs managed intensively indoors.

CATTLE NEMATODES

Prevention of PGE in growing cattle on a sustainable basis is best achieved by annual rotational grazing (cattle/sheep/crops) to create low risk pastures, but this is rarely possible on many livestock farms.

  • To control ostertagiosis in the autumn, dairy calves and suckled calves born during the previous autumn require preventative treatment in their first full grazing season unless they are on safe grazing.
  • If pasture egg contamination is suppressed by pulse release or continuous release bolus, repeated or long-acting anthelmintic injection as some of the options until at least mid-summer, most pasture larvae should have died off by that time and the pasture should remain safe for the rest of the season.
  • Alternatively, calves can be dosed and moved to aftermath at mid-summer, although a proportion of the strongest cattle should be left undosed to carry some anthelmintic-susceptible worm larvae onto the new pasture.
  • Where lungworm is a particular problem, there is still time to discuss control, including vaccination, with your veterinary surgeon.

 

Fig 8

Dairy calves and suckled calves born during the previous autumn require preventative treatment in their first full grazing season to control ostertagiosis in the autumn, unless they are on new grass leys or other verk low risk grazing.

Fig 9

There is still time to discuss this grazing season's parasite control with your veterinary surgeon.

 

 

Local farm conditions may vary so consult your veterinary surgeon. Parasite control should be part of your veterinary health plan