WEIGHT LOSS and reduced performance due to liver fluke disease in housed and out-wintered beef cattle is likely to be reaching peak levels about now, according to the January NADIS Parasite Forecast, sponsored by Merial Animal Health.

"Information on liver fluke damage should be requested from slaughterhouses to give an indication of the level of disease in the herd. This will help to inform control measures on individual farms and determine the ideal treatment policy," says Fiona MacGillivray, veterinary advisor for Merial.

"If cattle were not treated at the time of housing, a dose of nitroxynil (Trodax) or closantel should be given now to remove liver flukes picked up from pasture before animals were brought in.

"Dairy cows can also suffer reduced milk yield, lower quality milk and poorer fertility, despite adequate feeding, but treatment of liver fluke in dairy cows is more difficult. Albendazole and oxyclozanide are the only flukicides available for treatment of fluke in lactating dairy cows, with 60 or 72 hour's milk withdrawal, respectively.

An increased risk of type 2 ostertagiosis is likely this winter with large numbers of larvae inhibited in the abomasal wall due to a late challenge from autumn pastures. "If cattle were not treated with an anthelmintic at housing, now is the time to dose with a larvicidal wormer (or a combined wormer and flukicide, such as Ivomec Super) which will also remove lungworm infection if present," she says.

Above average temperatures in November allowed continued fluke larval development in some areas meaning many pastures remain infective.

Cases of acute fluke may still occur in January or even later on high risk farms.

Treatment with triclabendazole in January is recommended on farms which face a high risk of infection from pastures and any apparent treatment failures should be investigated to establish if triclabendazole resistance is present on that farm. Where possible sheep should be moved to fluke-free ground after treatment to reduce re-infection over the remainder of winter, she advises.

Cattle housed over the winter are also at risk of louse infestation. Heavy infestations can cause production losses due to reduced feeding time and damaged hides. To achieve best results, all cattle in direct contact must be treated on the same day, using an appropriate product.

Topical treatments are effective at controlling both lice and mange infestations during the housing period.