DULUTH, Ga. (November 29, 2022) — Lice and mange may not seem damaging to your bottom line, but they affect cow comfort. And cow comfort directly affects milk quality, animal immunity and production within a herd. That’s because the time that cows spend feeling itchy, scratching and standing up takes away from time producing milk.
“Don’t dismiss external parasites, and don’t wait until you’re seeing a lot of signs to address the problem,” said Jennifer Roberts, DVM, Boehringer Ingelheim.
Lice and mange are two common external parasites that can have extensive effects on cow comfort. Mange mites live on the tailhead and hindquarters of an animal, while lice are commonly found on the neck, shoulders and back. Both parasites cause intense itching and discomfort in affected animals.
“When we have any sort of condition that decreases cow comfort, that’s going to directly decrease production,” explained Dr. Roberts. “The most common mange we see in our dairy cows is called chorioptic mange, which is characterized by crusty, scabby areas of skin, typically around the tailhead or at the top of the udder.”
Lice are also a challenge. Dr. Roberts said that two common types of lice typically affect dairy cattle: biting lice and sucking lice. Biting lice irritate cattle by scraping the skin or hair, while sucking lice extract the blood of their host.
“Lice will be more distributed across the body of the animal than mange, and they will congregate in areas where they can stay a little bit warmer,” she added.
A successful approach to external parasite management has two main components: monitoring and treatment.
Monitoring: What to look for and when to be on guard
“Usually, what you see with lice is hair licked the opposite way on the cows,” Dr. Roberts noted. “You may also see some hair loss in areas because they are rubbing on posts or other things in the barn to try to scratch where it itches.
“Sometimes with mange, we will see hair loss around the head and neck, depending on the type of mite, but most commonly, we’re going to see hair loss around the tailhead,” she continued.
As far as when to be on the lookout, lice and mange infestations will ramp up as weather gets cooler in the fall and winter. “The cow’s hair grows a little bit longer during the winter months, and it allows the lice to burrow down, get away from sunlight, and get next to the cow’s body for warmth,” said Dr. Roberts.
Treatment: Be proactive
Start your treatment plan off by consulting a veterinarian. Some farms prefer to treat the whole herd once a year, while others will treat animals at certain stages of production, such as dry-off. Dr. Roberts doesn’t prefer one method over the other; rather, she defers to the option that will be the most attainable for the producer. “The protocol that you can implement and get done is going to be the best one to use,” she emphasized.
Other factors to consider with your veterinarian include previous use of pour-on treatments, severity of infestation and new additions to the herd.
“If you’re purchasing animals from external sources, make sure those animals get poured when they are coming into the herd, to try to minimize outside animals bringing those mange mites and lice in,” said Dr. Roberts.
When looking at topical pour-on dewormers, find one that is labeled for comprehensive parasite coverage. Most species of lice and mites can only infect cattle. However, sarcoptic mange can jump species to humans. As such, Dr. Roberts recommends choosing a dewormer that is labeled to treat sarcoptic mange as well as other common species to protect the health of not only the herd, but also the health of farm employees.
“Try to be proactive about addressing external parasites, because anything we can do to maintain cow comfort is going to help those cows be more productive,” she concluded.
Treating lice and mange can seem daunting, but with the help of your veterinarian and a high-quality dewormer, you can benefit your herd and your bottom line.