With the month of December coming to an end, the team at Rocky River hope you and your family had a wonderful holiday season and a Merry Christmas. We hope this holiday brought you some quality time with family and friends and wish you a Happy New Year!
Lice and Your Cattle Herd
As we settle into these cold winter months I wanted to bring to your attention a common annual pest that can afflict your cattle herd. Lice are an annoying pest. Unlike other bugs, they increase their numbers during the winter months. These bugs seem to thrive when it is the harshest outside. Through the months of December to February, we see peak numbers. Then, numbers decline come March as we head into spring. The parasite is transmitted through direct contact between animals, so as the cattle huddle together more during colder temperatures it makes transmission easier. Reduced light during the winter months also seems to play a role in the increase in numbers through the winter.
There are two main types of louse that afflict cattle, one being the biting louse and the other being the sucking louse. They are small, flat bodied insects with 6 legs that allow them to hold onto the hair of your cattle. Like other parasites, they cannot survive off the host for more than a few days. Sucking lice have a more narrow head that allows them to attach to the cow and feed off blood. Biting lice have a large triangular head and they feed on cattle by scraping the skin and base of the hair.
Effects of Lice
As stated previously, the biting and sucking lice attach and move around the cow and feed either off the skin or blood. This movement and feeding can cause irritation on the skin leading to common symptoms noted by producers. When you have lice on your cattle you may notice things like hair loss, scratching, unthrifty appearance, and tufts of hair getting caught on fencing and trees.
High infestations of lice have the ability to decrease weight gain in your herd by up to 0.2 lb/day. All that scratching and irritation keeps your cattle from eating well during the winter. With the hair loss comes the loss of that winter hair coat and makes your cattle more susceptible to the cold. This causes a higher nutritional demand from the cattle in order to maintain their body condition through winter. High infestations of sucking lice can even cause low level anemia in your cattle.
To diagnose lice in your herd it’s recommended to run your herd through the chute and run your hands through the coat to identify the lice in your cattle. Anytime you purchase new cattle during the winter, always check them for lice prior to introducing them into your herd.
If your herd is experiencing hair loss and you aren’t able to identify lice on your cattle then there could be another issue at hand. Some other conditions that can cause hair loss in cattle include mites, mineral deficiencies, inadequate nutrition, and natural shedding.
Treatment Options
Like other parasite management strategies, there are multiple routes available for producers to treat and control lice in their herd. These options can be categorized as sprays, spot ons, injectables, and pour on products. Producers should refrain from using either systemic injectable products or systemic pour on products from November 1st through February 1st, as these products can cause a host reaction as cattle grubs migrating through the esophagus or spinal cord are killed. During these months it’s recommended to use some version of a nonsystemic topical product.
Treating louse effectively in your herd all comes down to application timing. As discussed earlier in this article, lice are most prevalent in the coldest months of the year. So, if you treated for lice in early fall, your herd may need a second round of treatment to get them through the winter. Also, different products require different application timelines and reapplication. It should also be stated that not all products treat all species of lice. Always read the label of the product you are using, or please call us at the office for recommendations on treating lice. If using topical products, avoid using it when the back of your cattle is wet or covered in dirt. No matter the product being used always follow the meat withdrawal guidelines. Below are some great resources if you’re interested in reading further into the topic.
https://beef.unl.edu/cattle-lice
https://www.uky.edu/Ag/PAT/recs/livestk/recbeef/beeflic.htm
https://wilkes.ces.ncsu.edu/2016/06/control-of-lice-in-cattle/
Different operations will require different strategies to cope with lice infestations. If you have any questions regarding the topics discussed in this article, please don’t hesitate to contact us.
Written By: Dr. Gunner Edgell
Rocky River Large Animal Veterinary Clinic is here to serve you and your animals.