Winter housing brings with it many challenges for animal health, including the control of external parasites, namely lice and mites. Last week, I spoke to a number of farmers who already have seen their stock beginning to look itchy.
There seems to be some evidence across the world that lice and mites are now also showing signs of resistance to modern treatments. Talking to Irish vets this could also be the case. However, with different mites and lice responding differently to various treatments, we need to be careful with our next steps.
There are different types of lice and mites. Lice can suck or bite, and there are three species of mites: psoroptes, chorioptes and sarcoptes
This may be important for farmers who are getting a poor response to treatments. There can be transfer of lice and mites from sheep to cattle, but this is limited, as they have different diets on the skin itself.
Environment
External parasites cause problems indoors, as it is the perfect condition for them to breed and spread. Pay careful attention to stocking densities, as the closer animals are to each other, the more likely mites or lice are to spread.
They like the warm climate under the hair of housed cattle. While clipping the backs isn’t directly linked to reducing mites, it helps in my opinion. Clip the backs with a good clippers before any topical treatments, to allow for less sweating over the winter months.
Improving ventilation in sheds also really helps with all types of infectious disease. Older cattle really benefit from sheds with good airflow. Get inlets and outlets correct to maximise the stack effect. Get your vet to assess your sheds on a still day to check airflow, simple adjustments to sheds can’t be underestimated.
Treatment and control
The key is to get preventative treatments into cattle before lice and mites start breeding. There are a number of options, including:
Spot ons: (pyrethroids) work well for lice and psorotpes mites. In heavy burdens they may need to repeated in four weeks.Amitraz: works well for both lice and mites. This is often applied using a nap snack sprayer or through a power hose on cattle. This works well by correct dilution rate and soaking cattle with heavy infections. It needs to be repeated in seven to 14 days in most cases.Macrocyclic lactones (Ivermectin): This can be given by injection or pour on. It also has the added advantage of treating worms. Where choriopte mites or biting lice are present, you may get poorer results. There is also the issue of using them on cows who should not need worming.The most important thing for farmers to do is review their treatment plans and if they are not working, consider skin scrapes to identify what parasites are actually on the skin. This can be done by your vet. External parasites can really affect thrive this winter, so now is the time to get them under control.
Winter housing brings with it many challenges for animal health, including the control of external parasites, namely lice and mites. Last week, I spoke to a number of farmers who already have seen their stock beginning to look itchy.
There seems to be some evidence across the world that lice and mites are now also showing signs of resistance to modern treatments. Talking to Irish vets this could also be the case. However, with different mites and lice responding differently to various treatments, we need to be careful with our next steps.
There are different types of lice and mites. Lice can suck or bite, and there are three species of mites: psoroptes, chorioptes and sarcoptes
This may be important for farmers who are getting a poor response to treatments. There can be transfer of lice and mites from sheep to cattle, but this is limited, as they have different diets on the skin itself.
Environment
External parasites cause problems indoors, as it is the perfect condition for them to breed and spread. Pay careful attention to stocking densities, as the closer animals are to each other, the more likely mites or lice are to spread.
They like the warm climate under the hair of housed cattle. While clipping the backs isn’t directly linked to reducing mites, it helps in my opinion. Clip the backs with a good clippers before any topical treatments, to allow for less sweating over the winter months.
Improving ventilation in sheds also really helps with all types of infectious disease. Older cattle really benefit from sheds with good airflow. Get inlets and outlets correct to maximise the stack effect. Get your vet to assess your sheds on a still day to check airflow, simple adjustments to sheds can’t be underestimated.
Treatment and control
The key is to get preventative treatments into cattle before lice and mites start breeding. There are a number of options, including:
Spot ons: (pyrethroids) work well for lice and psorotpes mites. In heavy burdens they may need to repeated in four weeks.Amitraz: works well for both lice and mites. This is often applied using a nap snack sprayer or through a power hose on cattle. This works well by correct dilution rate and soaking cattle with heavy infections. It needs to be repeated in seven to 14 days in most cases.Macrocyclic lactones (Ivermectin): This can be given by injection or pour on. It also has the added advantage of treating worms. Where choriopte mites or biting lice are present, you may get poorer results. There is also the issue of using them on cows who should not need worming.The most important thing for farmers to do is review their treatment plans and if they are not working, consider skin scrapes to identify what parasites are actually on the skin. This can be done by your vet. External parasites can really affect thrive this winter, so now is the time to get them under control.
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