The June NADIS Parasite Forecast sponsoredby Merial Animal Health, advises cattle farmers to be alert for signs oflungworm in their herds this summer. Symptoms may appear in unvaccinatedcalves, naive adults and those cattle which have not been treated with ananthelmintic.
When checking stock, signs of coughing andblowing could indicate the presence of the parasite in the lungs. The classicstance of an infected animal is mouth-breathing with the head and neckout-stretched in an attempt to get air in to the lungs. A rapid loss of bodycondition and weight may also be indications of lungworm burden.
Lynda Maris, Brand Manager at Merial AnimalHealth, sponsors of the NADIS Parasite Forecast, says: Lungworm caneffectively be treated with anthelmintics including ivermectin and eprinomectinwhich provide persistent activity and so prevent re-infection.
Products such as Ivomec Classic and Eprinexcan be used in a strategic worming programme to control gutworm infestation inautumn-born calves and to suppress the risk of lungworm infection, whichgenerally peaks July to September. In the event of a lungworm outbreak all animalsin the herd should be treated promptly. An added advantage of Eprinex is thatit has a zero milk withhold, so in the case of milking cows they can still betreated with no need to throw away the milk.
As far as sheep are concerned, producers withpastures that have not been grazed this season can consider them safe grazingfrom mid-summer onwards and therefore ideal for fattening lambs. Any larvaepresent on the pasture will have died-off without the presence of a sheep host.
However, any lambs grazing on contaminatedpastures are still at risk of PGE and should be treated with an anthelmintic.Faecal egg counts carried out after June can be used to determine treatmentsrequired until housing.
Mrs Maris says: We have had some fine weatherlately which can dry out faeces, with the larvae enclosed in the dung. Oncerain hits after a dry period, the larvae are release from the faeces on to thepasture. This can cause a real threat to livestock.
A targeted anthelmintic treatment approach canbe taken where only the lambs which are failing to meet expected growth ratesare treated.
Mrs Maris adds: The method of targetingindividual animals can save noticeable amounts of money. It is vital to weighlambs every 3 to 4 weeks in order for this method to be successful. A targetedapproach also helps to reduce any possibility of resistance building up in theflock.
Farmers often forget to include rams intheir flock parasite control programme plan. Rams are high value animals andcrucial to the flock so it is vital that they are appropriately dosed andregularly checked.
The first cases of blowfly strike are beingreported. While farmers are waiting for the wool to rise and a period of goodweather before shearing, flies and maggots can be a particular problem. Thepotential for fly strike is increased by any scouring caused by parasiticgastroenteritis and nematodirus, which provides a fly-friendly environment. Anappropriate ectoparasitide should be used as a control. In many cases, onceshorn, animals will suffer less from fly strike.