Early in the year worms are the main challenge to lambs but, as the summer progresses, the scourge of liver fluke begins to raise its head.
At this time of year some sheep farmers start to realise that their lambs are carrying a mixed infection of both fluke and worms. Products with a combination of moxidectin and a flukicide such as triclabendazole have persistent activity and are effective against adult fluke and also early immature fluke. Due to the recent wet summers fluke has become much more of a problem, even on traditionally dry land.
Approximately 75pc of livers from lambs last winter were discarded as they were not fit for human consumption due to the level of liver fluke damage. This indicates that store lambs have not been adequately treated for liver fluke at the back end of the year. These heavier lambs also need a worm dose in the autumn as it is unlikely they will have sufficient protective immunity.
Fluke problems have traditionally been associated with late summer and autumn, but in recent years on many farms it has also been associated with disease in the spring and early summer.
Adult ewes may require a fluke drench at lambing, along with a worm treatment to suppress the peri-parturient rise.
A pre-tupping worm dose for ewes is not always indicated and should only be undertaken if needed. The usual suspects requiring a fluke and worm drench at this time of the year would be thinner ewes and scouring ewes. Roundworm infestation should be confirmed using faecal egg counts.
Buying in sheep can be a risky business. Buyers would be well advised to treat all in-coming sheep with a quarantine dose. Treating bought-in animals with a fluke drench that treats all stages of liver fluke is important to avoid introducing new parasites to the flock.