Worms like it wet!
Worms like it wet!
WARM, wet autumn weather could lead to heavy worm burdens in cattle and producers are advised to protect stock at housing to prevent illness next spring.
As the autumn progresses and temperatures fall, worms do not develop to the infective stage. Instead once ingested they become dormant in the stomach wall of the cattle, explains SAC vet officer Mark Crawshaw.
But dormant worms can cause severe damage to the stomach wall when they emerge simultaneously in early spring.
This can be fatal and so Mr Crawshaw recommends dosing some cattle at housing.
Treating at this time is effective because once housed any worms shed as a result of the treatment still cannot develop to the infective stage and, therefore, there is no risk of reinfection.
He advises using a benzimadazole or ivermectin-type wormer for vulnerable stock such as those in their first year.
"These wormer types are particularly effective against dormant worms. However, previous wormer types must be reviewed with the help of a vet so that overuse of any one product – and hence anthelmintic resistance – is avoided.
"Dosing older cattle – which should have developed immunity and so harbour few worms – is not normally recommended."
But Mr Crawshaw warns that in some cases older cattle may have been treated so effectively that they have not built up natural immunity – and these stock would need treating.
He suggests producers contact their vet for advice on a worm control strategy in such cases.