Autumn and Winter Liver Fluke Forecast for N. Ireland

Staff at the Veterinary Sciences Division (VSD) of the Agri-Food and Biosciences Institute (AFBI), using a forecasting system based on rainfall data, have predicted that the overall risk of liver fluke infection during this autumn and winter in Northern Ireland will be high.

Although the rainfall for May was 26% higher than the Northern Ireland average for 1981-2010, the rainfall for the period June to August was 24% lower.

July received only 61% of the expected rainfall. The number of days with 1mm or more of rain was less than the Northern Ireland average for June, July and August, with July having almost 50% fewer days. The drier conditions this summer would have allowed some land to dry out, reducing the ability of the intermediate host, the snail Galba truncatula, to breed, and also the likelihood of fluke to develop within the snails.

On the other hand, areas that have remained wet enough to support fluke development have seen mean temperatures for June, July and August 1˚C above the Northern Ireland average, with July 2.5˚C higher. Mean temperatures of 10˚C or higher are necessary both for the snail intermediate host to breed and for the fluke to develop within the snail. A temperature of 10˚C or above is also necessary for fluke eggs to develop and hatch. It is only when temperatures rise to 15˚C and, are maintained above this level, that significant multiplication of snails and fluke larvae ensues. The mean temperature for the period June to August was 15.1˚C.

These weather conditions, along with the fact that many pastures were heavily contaminated last year, indicate that there will be a high risk of acute fluke disease this autumn. In addition, the dry weather in September and October has allowed farmers to graze sheep and cattle late into autumn and on pasture where the water table remained sufficiently high to permit the snail population to spread unchecked. Thus stock may continue to be exposed to high levels of fluke larvae on the pasture, and this is likely to continue until the onset of frosty conditions.

Liver fluke disease can occur in either acute or chronic forms.  The acute form occurs in sheep and is caused by the migration of large numbers of immature flukes through the liver. Acute liver fluke is often a fatal disease and has serious welfare implications. Signs of severe infections include distended painful abdomen, anaemia and sudden death. In less severe cases poor production and growth, coupled with reduced appetite and abdominal pain are apparent. Chronic liver fluke disease is more common than the acute form and occurs in both sheep and cattle, usually during the winter and spring although infection can persist throughout the year.

Affected animals may exhibit anaemia, ill thrift, reduced production or ‘bottle jaw’ (swelling under the jaw).

Fluke infection can cause a reduction of 5-15% in the milk yield of dairy cows and loss of growth in fattening lambs and cattle.  It is therefore a source of considerable unseen financial loss to the agricultural industry in Northern Ireland. Fluke infections in dairy cattle can also predispose to metabolic conditions such as ketosis and infectious diseases such as salmonellosis. The same is likely to be true for sheep. Flockmasters and veterinary surgeons also need to be aware of the predisposition to Black disease caused by migrating liver fluke. Cattle and sheep with access to flukey pastures should be fully vaccinated against this clostridial disease.

All farmers should review their fluke control measures at this time of year. Access to snail habitats (wet and poorly drained areas) should be reduced or sheep taken off the land and housed or moved to new clean pasture. However, in most cases, control will be based on the strategic use of anthelmintics, employing a product effective against the life cycle stages likely to be present in the flock or herd at the time of treatment. This is particularly important in autumn when acute fluke infection occurs in sheep and pick-up of infection by sheep and cattle is still taking place. At this time of year treatment effective against all immature and mature forms is needed. Such treatment is necessary in out-wintered sheep once or twice in autumn and again in January, coupled with a treatment effective against adult flukes in early spring. This regime should significantly reduce the fluke burden on individual farms. It is important to remember that products other than triclabendazole are active ONLY against late immature and adult flukes, so two treatments during the spring may be needed to ensure removal of flukes acquired late in winter or early in spring.

Treatment of chronic (adult) infections in cattle as well as sheep during the winter or early spring is important to help reduce pasture contamination with fluke eggs. Use of an anthelmintic with activity mainly against adult flukes may be sufficient in these circumstances, but if the recent trend of mild winters continues, out-wintered sheep will be liable to pick up acute infection much later than expected. Treatment of cattle will depend on the timing of housing and the effectiveness of particular anthelmintics against the fluke present on your farm. However the flukicide programme used has to be on a ‘know-your-farm’ basis and no one set of recommendations will cover all flocks or herds.

Farmers need to be aware that resistance to fluke treatments is an emerging problem and has been detected in Northern Ireland. On some premises, products containing triclabendazole (the only flukicide currently licensed in UK and Ireland that is effective against the immature stages of liver fluke which cause acute fasciolosis in sheep) have been used almost exclusively for a number of years. On such farms it is possible that triclabendazole-containing products may now be less effective in controlling fluke infection, and for treating acutely-ill animals. However, no other products are effective for treating acute fasciolosis, so triclabendazole should be considered for use in emergency situations in conjunction with closantel, in an attempt to partially reduce acute fluke burdens and save animals. Concurrent use of triclabendazole and closantel this autumn is particularly important because of the likelihood that fluke infection was acquired earlier in the year, due to carry-over of larvae on pastures heavily contaminated in 2012-13, or in over-wintered snails. The effectiveness of anthelmintic treatment on individual farms should be checked by taking dung samples 3-4 weeks after treatment and submitting them, through your veterinary surgeon, for laboratory examination.

In recent years, due to a succession of unusually wet summers, stomach (rumen) flukes have become common in sheep and cattle in NI. The intermediate snail host sheds infective metacercarial larvae unto the pasture, especially during periods of flooding. Adult rumen flukes are less damaging to sheep and cattle than liver flukes, but heavy infections of immature worms may cause diarrhoea, ill-thrift and, exceptionally, death in young animals. Heavy burdens of adult rumen flukes have been reported to result in poor productivity in dairy or meat-producing animals. If you suspect that stomach fluke infection may be a problem on your farm, you should contact your veterinary surgeon to arrange for appropriate laboratory testing, and to discuss treatment options.

Remember that liver flukes, particularly in acute infections, are potentially a much more serious risk to the welfare and productivity of animals than stomach flukes. The choice of flukicides to use in autumn must reflect this. Treat first with liver fluke in mind and second for rumen fluke; if need be, use different treatments for each parasite.

The use of all currently available anthelmintics for the control of fluke in lactating dairy cows requires milk to be withheld. Treatment at drying off may therefore be more cost-effective. Please note that some fluke treatments are not suitable for use in dairy animals both while milking and whilst in calf. Given the importance of flukicides at this time of the year, it is pertinent to remind farmers of the need to avoid unacceptable residues of anthelminitics, and indeed of all veterinary medicinal compounds, in food of animal origin.  Farmers are reminded to apply the appropriate dosing and withdrawal periods, as outlined in the manufacturer’s product data sheet. Monitoring for residues takes place throughout the year.

Advice on the most suitable anthelmintic and other control measures can be obtained from your veterinary surgeon. The AFBI veterinary laboratories at Stormont and Omagh can assist your veterinary surgeon by testing dung and blood samples from livestock for evidence of fluke infection and associated liver damage. Further information on liver fluke disease in cattle and sheep may be found at:

http://www.afbini.gov.uk/index/services/diagnostic/adds/adds-articles-diseases.h

(Source – Farming Life – 21/10/2013)

 

 

 

 

 

 

 

 

 

 

 

 

IFA – Worm and Fluke Dose Price Survey – Autumn 2013

 

Product	Pack Size	Pour on	Inj	Oral	*Vat inclusive price range €
Albex 10%	5l			x	69.00 – 85.00
Chanaverm Plus Oral Solution	10l			x	29.00 – 35.00
Closamectin Pour On Solution For Cattle	2.5l	x			265.00 – 295.00
Closamectin Pour On Solution For Cattle	5l	x			529.00 570.00
Cydectin Sheep 0.1%	5l			x	135.00 – 145.00
Cydectin Sheep 0.1%	2.5l			x	75.00 – 85.00
Cydectin Sheep 1%	200ml		x		100.00 – 120.00
Cydectin Triclamox Oral	2.5l			x	105.00 – 130.00
Cydectin Triclamox Oral	5l			x	225.00 – 230.00
Dectomax 10	200ml		x		120.00 – 137.00
Duotech	2.5l			x	75.00 – 80.00
Endofluke 10	2.5l			X	30.00 – 47.00
EndospecSC 10%	5l			x	73.00 – 79.00
EndospecSC 10%	2.5l			x	45.00 – 55.00
Enovex 0.5%	2.5l	x			44.00 – 46.50
Eprinex 0.5%	2.5l	x			220.00 – 245.00
Eprinex 0.5%	5l	x			400.00 – 455.00
Fasinex 240	2.2l			x	225.00 – 245.00
Fasinex 240	5l			x	440.00 – 475.00
Fasinex – Super 19.5%	2.2l			x	130.00 – 159.00
Fenbenor 10%	2.5l			x	37.00 – 45.00
Flukiver	250ml		x		22.00 – 28.00
Flukiver 5%	5l			x	119.00 – 125.00
Ivomec Classic	200ml		x		89.50 – 109.40
Ivomec Classic	500ml		x		202.00 – 225.00
Ivomec Classic	50ml		x		28.00 – 39.00
Ivomec super	500ml		x		200.00 – 210.00
Levafas Diamond	4l			x	50.00 – 70.00
Levafas Diamond	1l			x	19.00 – 20.00
Levafas Diamond	2.5l			x	44.00 – 46.00
Eprizero 5	2.5l	x			225.00 – 235.00
Eprizero 5	5l	x			430.00 – 450.00
Noromectin 0.5%	1.25l	x			37.50 – 50.00
Noromectin 0.5%	3.5l	x			81.00 – 95.00
Noromectin 0.5%	7l	x			155.00 – 200.00
Oramec 0.8%	5l			x	68.00 – 85.00
Panacur 10%	1l			x	62.00 – 65.00
Panacur sc 2.5%	2.5l			x	61.00 – 65.00
Supaverm	2.5l			x	85.00 – 89.00
Supaverm	5l			x	145.00 – 160.00
Tramazole 10%	1l			x	26.00 – 30.00
Tramazole 10%	2.5l			x	47.00 – 51.00
Trodax 340	2 x 500ml		x		199.00 – 205.00
Trodax 340	250ml		x		57.00 – 66.00
Vecoxan	1l			x	105.00 – 112.00
Vecoxan	2.5l			x	250.00 – 260.00
Zanil	5l			x	64.00 -73.00
*Prices reported by farmers to IFA as part of a National Fluke & Worm Dose Price Survey.