If your cow has lice, it’s important to get rid of them before they spread. Lice are small insects that live on the skin of cows and lay their eggs there, which hatch into larvae that feed on the hair or skin of their host. If a cow has lice, it can be a serious problem for both the animal and your operation because lice can cause irritation and lead to infections in your herd.
There are two types of lice that affect cattle: chewing lice and sucking lice. Chewing lice feed on the hair or skin of an animal, but do not lay eggs like sucking lice do. The chewing variety is more common than sucking louse infestations in dairy herds. This type of parasite feeds on the skin or coat of a cow and causes irritation, itching, and even mange in severe cases.
Sucking lice can also cause problems for dairy cows if left untreated for too long. These parasites lay their eggs inside the coats of their hosts so they can continue feeding off them throughout their development cycle before emerging as adults ready to mate with other adult female parasites laying eggs inside other animals’ coats too.
There are a few ways to get rid of cow lice. First, you need to delouse every animal. Whether it is a herd or a single cow, it’s important to treat each animal at the same time to prevent reinfestation. You should also use judicious timing when delousing cattle.
While chewing lice as medicine for cow lice has some advantages over injectable products, the debate rages over its economic effects. Although chewing lice may reduce the itch of cattle and reduce the risk of cold stress, it also reduces the immunity of the animal, making it vulnerable to secondary infections. To avoid this, producers should treat cattle early in the spring and fall, but should not treat them too late.
The effectiveness of chewing lice as medicine for cow lice depends on several factors, including the host’s immunity, the level of crowding, the amount of food available, and the overall health of the animal. Heavy infestations of chewing lice can lead to severe itching, pruritus, alopecia, and excoriations. In addition to the unpleasant symptoms, the animals suffering from an infestation often lose significant fleece. Besides cow lice, other livestock, such as sheep, cats, and guinea pigs, can display large-scale infestations of chewing lice, and show signs of skin debris in their fur.
While chewing lice and sucking lice have similar life cycles, the biology of both is different. While chewing lice are wingless and live on their host, sucking lice have elongated mouthparts and wide heads. They have a bloodmeal diet and can survive off the host for several days. Infestations of both types of lice are often seasonal, with the highest incidence of cattle tail lice in the spring and summer.
The eradication strategy was a success in 28 of 33 herds, though there were still some complications. Despite effective treatment, lice remained present in 33% of herds three to six months after treatment. One herd had both sucking and biting lice. The study found that failure to treat newly introduced animals was a major risk factor for reinfection.
The most common type of lice is sucking and chewing. They irritate the cattle and cause them pain and discomfort. A prolonged infestation can result in a decrease in performance and weight loss. While chewing lice are generally smaller and less invasive, they may be more painful than sucking lice. Biting lice are reddish brown in color and are about two millimeters long. They typically live on the neck, shoulders, back, and rump.
Various commercial products are available for treating cow lice. These include pour-on and injectable macrocyclic lactones. These are most effective for killing sucking lice but do not kill eggs. Thus, a second treatment will be required. These products must be applied before winter.
There are several types of insecticides available for the control of cow lice. The most common types are systemic and non-systemic insecticides. These products work to kill both adult and larval lice. However, some of them may only control sucking lice, and may not be effective against tail lice or biting lice. For optimal control, a systemic insecticide should be applied twice, one to infested areas and another to kill eggs.
The number of cow lice in an area depends on several factors. One factor is the number of cattle in an area. An infestation of cattle usually increases during the fall and winter months. The intensity of the light may also play a role in the number of louse infestations. Lice infestations usually decline as the weather warms. Once an infestation begins, it rarely goes away without the use of an insecticide.
An average of ten lice per square inch is required for significant control. However, the economic impact of lice has not been fully assessed. To produce a significant reduction in weight gain, at least ten lice must infest the animals. In addition to these economic consequences, the energy that the lice “steal” can severely impact an animal’s health. The symptoms of a lice infestation may include anemia, poor gains, and slower recovery from diseases.
Re-treating cattle with insecticides is an effective method of controlling the population of cow lice. Treatments should be repeated in February and March, and the residual effect may last into the spring. Some of the more effective products will also allow the cattle to self-treat themselves. The use of insecticide dust bags and backubbers is also an effective option. However, it is crucial to avoid under-treating an animal because a heavy infestation can cause the animal to rub out patches of hair that may cause injuries.
One study found that an insecticide containing 1% lambda-cyhalothrin was effective in eliminating the biting lice. The study also found that the product’s efficacy lasted for two to eight weeks after treatment. The results of this study are similar to the results of similar studies conducted in other Northern European countries.
Several states have recommended the use of insecticides with backrubbers. Hoffman, of the Entomology Research Branch laboratory in Corvallis, Oregon, discovered toxaphene through self-treatment devices. However, this treatment is only effective if the user follows the instructions carefully.
The researchers found that the treatment was effective in 28 of 33 herds after three to six months. However, the results were not entirely consistent. In some herds, the eradication was not complete and some reinfection was observed after three to six months. Despite this, eradication was achieved in the remaining three herds.
Prevention of reinfection
One of the most important components of successful cattle lice management is prevention. Properly treating cattle with medicine can prevent reinfection. Recurrence is extremely unlikely. This is because cattle lice are permanent and obligate ectoparasites, meaning that they cannot survive without their host for more than a few days. The best way to prevent reinfection is to treat the cattle as soon as you notice the signs of an infestation.
The treatment of a herd with medicine for cow lice should begin 7-14 days prior to farrowing. It is also important to treat gilts and boars at least twice a year. For herds that have been exposed to contaminated soil or pasture, treatment should be repeated as needed.
The results showed that eradication is effective in 28 of 33 herds, but lice were still present in 5 herds three to six months after treatment. Biting lice were present in all five herds, and sucking lice in three of them. In addition, nine out of the 28 herds were reinfected within 12 months, six of which had sucking lice and two were reinfected with both types. One factor that increased the risk of reinfection was a failure to treat newly introduced animals.
In open herds, eradication is a valid strategy for lice control. It is important to apply pre-treatments for calves and young animals, which are the age groups most susceptible to reinfection. In addition, calves and young animals are most commonly purchased. Hence, reinfection by calves and young animals is high when no pre-treatment is performed.
Using an effective medicine for cow lice is crucial for eradication. Several studies have shown that medication for cow lice treatment is effective in preventing reinfection. However, this is not a foolproof method, and there are many pitfalls to consider. Even if the eradication program was successful, it is essential to monitor the risk of reinfection. So, before starting an eradication program, make sure that you have all the essential information regarding the risk of reinfection.
In a Norwegian study, lice prevalence was assessed in 28 dairy herds. Five of these herds participated in the study as a pilot. The animals in the pilot group were examined in December 1993 and treated for lice. They were followed for 2.5 years after treatment. Then, they were examined again.