Controlling liver fluke this winter
A year of weather-related challenges has heightened the risk of liver fluke infection on some farms. Tommy Cox, DairyBeef 500 Advisor, shares key advice on the most appropriate treatment programmes to follow.
After a year of grazing challenges - including delayed turnout, higher than normal rainfall levels in the west and north and colder conditions in the south this summer - the final stretch of the year was a saving grace due to the mild and dry run in resulting in excellent grazing conditions up until housing.
With cattle now indoors on nearly all farms and their risk of picking up internal parasites reduced, now is a good time for farmers to start thinking about their parasite control programmes to ensure performance is maintained during the costly indoor period.
Liver fluke
Lack of thrive, poor appetite and reduced weight gain are all ill effects of liver fluke, therefore farmers need to act early to prevent any issues arising.
Once ingested, liver fluke begin to feed and grow. It takes approximately 12 weeks for the flukes to grow to adult stage, at which point they start to lay eggs. These eggs pass out in the faeces of the animal and, when conditions are suitable, they hatch and use the mud snail to continue the life cycle.
During this 12 week period, the fluke are classified according to their stage of development:
- First 5-6 weeks – early immature fluke
- Weeks 6-10/11 – immature fluke
- Week 11 + - adult fluke
Monitoring
Faecal sampling can be used as an aid in monitoring liver fluke. However, as only mature liver fluke shed eggs, farmers need to be cautious in waiting that long if there is a historical issue on their farm.
Animal Health Ireland’s Beef HealthCheck reports, available on a farmer’s ICBF profile, provides useful information on the level of liver damage arising from liver fluke infection in animals previously finished on the farm. This year, higher than normal levels of liver damage have been detected in some processing plants due to fluke damage.
Treatments
There are a number of different flukicides on the market, but certain products are only effective again certain stages. Some products are only effective against the adult stage, therefore careful thought needs to be given as to what product and when it is used.
If using a product that only treats adult fluke, cattle need to be in at least 11 weeks to ensure an effective treatment.
In areas where burdens are high and farmers need to intervene quick, triclabendazole based products - which cover all three stages - can be given a few weeks post housing. There is some known resistance to this product in certain parts of the county, so caution is advised.
In other cases, there are a number of products that are also effective against mature and immature fluke, and these will give an effective treatment if administered six weeks after housing.
When selecting a product, check the product label to identify the stages of liver fluke treated. Table 1 outlines examples of drugs useful in the control of liver fluke in cattle, and the stages treated.
Table 1: Active ingredients and the stages of liver fluke treated
| Active ingredient | Liver Fluke Stage | ||
|---|---|---|---|
| Early Immature | Immature | Mature | |
| Triclabendazole | Yes | Yes | Yes |
| Closantel | Yes | Yes | |
| Clorsulon | Yes | ||
| Oxyclozanide | Yes | ||
| Nitroxynil | Yes | Yes | |
| Rafoxanide | Yes | Yes | |
| Albendazole | Yes | ||
When selecting a product for finishing animals, farmers must be mindful of withdrawal period as some products having quite long withdrawal periods.
More information
Dr. Natascha Meunier, Beef HealthCheck Programme Manager, is on this week’s Beef Edge podcast to discuss how to control liver fluke effectively and understand it better.
Listen in below:
Tommy Cox is an advisor on the Teagasc DairyBeef 500 Campaign. Find out more about the Teagasc DairyBeef 500 Campaign here.