Timing critical when dosing for fluke
“Treating cattle with the wrong product at the wrong time can be ineffective, costly and may even lead to anthelmintic resistance,” warns Maura Langan, Norbrook Vet Advisor.
Most cattle in Ireland will receive a fluke treatment during the housing period. Pasture contamination increases throughout the summer months, so this reflects the increased risk. Housing also ensures a period where cattle aren’t able to pick up any further infection.
“Cattle will develop an immunity to gut worms, but this doesn’t really happen with liver fluke,” explains Maura. “Although they can tolerate a low-level infection, the damage done by fluke to the liver and bile ducts can cause permanent scarring. Studies have also shown that subclinical liver fluke infection in breeding stock can result in reduced fertility, increased calving intervals and an increase in metabolic diseases post-calving. So an effective treatment at this time of the year can help a range of health outcomes, as well as improve liveweight gain and carcase formation in growing cattle.”
There are a range of different flukicides on the market and they are generally classified according to the stages of fluke they are effective against. For this reason, it is important that the most appropriate product is used at the correct time in the fluke season. Triclabendazole is effective against all stages of fluke and for many years was the ‘go to’ product. However, because of concerns about resistance and the need to preserve its usefulness in sheep, triclabendazole is now only recommended for use in cattle in specific circumstances.
Other popular fluke drenches are only effective against adult fluke, so cattle would need to be
treated 12 weeks post-housing to ensure a full fluke kill. Treatment options for milking cows are
limited, so farmers will need to consult with their vets as to the most practical product choice and
Solantel Pour-On is the first single-active, pour-on flukicide for cattle to be licensed in the UK and Ireland. Solantel Pour-on contains closantel and is licensed for the treatment of late immature (>7weeks) and adult Fasciola hepatica (liver fluke) infestations in cattle.
Treating cattle with Solantel Pour-On 7 weeks after they are housed will increase the number of susceptible liver fluke at the time of treatment and therefore lead to a more complete fluke kill.
Alternatively, if a heavy fluke burden is suspected, or if cattle are close to their finishing weights, then treating at the point of housing may be a more appropriate treatment option.
“As an industry, we are moving away from routine worming at housing unless there is a demonstrated need. Adult cattle that have good immunity to gut worms or cattle that have received a persistent wormer such as Taurador 5 weeks prior to housing, are unlikely to need a worm dose at housing,” cautions Maura. “Treating cattle for worms unnecessarily can promote anthelmintic resistance and, of course, it costs the farmer time and money.”
“However, many cattle will still need to be treated for fluke. By using the right product at the right time, we can protect animal medicines for the future, ensure healthy, productive, sustainable cattle and help to reduce pasture contamination by putting fluke-free cattle back onto grass in the spring.