Maybe this is what a picture of a trouser or underpants louse and a cow louse looks like

Underpants lice, scientifically known as Pthirus pubis, are tiny parasitic insects that infest human hair, primarily in the pubic region, but they can also be found in other coarse body hair such as that on the chest, armpits, and, rarely, eyelashes. These lice are different from head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus), as they have evolved to thrive in different environments on the human body.

Appearance and Life Cycle

Underpants lice are small, about 1.1–1.8 mm in length, and have a crab-like appearance due to their broad, flat bodies and large front claws, which they use to cling to coarse hair. The life cycle of these lice consists of three stages: egg (or nit), nymph, and adult. The eggs are oval and usually yellow or white. They are cemented to the base of hair shafts near the skin. After about a week, the eggs hatch into nymphs, which are immature lice that resemble smaller versions of the adults. Nymphs mature into adults in about two to three weeks. Adult lice can live for about 30 days on a human host but will die within 1-2 days if separated from the host, as they rely on human blood for nourishment.

Symptoms and Transmission

The primary symptom of an underpants lice infestation is intense itching in the infested areas, caused by the lice biting the skin to feed on blood. The bites can lead to small, bluish-gray spots on the skin, a condition known as "maculae ceruleae." In some cases, people may develop secondary bacterial infections due to scratching. While underpants lice are often associated with sexual contact, they can also be spread through close personal contact or by sharing contaminated clothing, bedding, or towels.

Diagnosis and Treatment

Diagnosing an underpants lice infestation usually involves a visual examination of the affected areas by a healthcare provider. The lice and their eggs are often visible to the naked eye, although a magnifying glass may be needed in some cases. The presence of nits attached to the hair shafts is a clear indication of an infestation.

Treatment for underpants lice typically involves the use of topical insecticides, such as permethrin cream or a pyrethrin-based shampoo. These treatments are applied directly to the affected areas to kill the lice. In some cases, a second treatment may be necessary about a week later to kill any newly hatched nymphs. It's also important to wash clothing, bedding, and towels in hot water and dry them on a high heat setting to kill any lice or eggs that may be present.

Prevention and Public Health Concerns

Preventing underpants lice infestations involves practicing good hygiene and avoiding sharing personal items such as clothing and towels. In situations where there is a risk of infestation, such as during sexual contact with an infested person, it is important to seek treatment promptly and inform any recent contacts so they can also be treated if necessary.

Underpants lice are not considered a major public health concern, as they are not known to transmit diseases. However, infestations can be uncomfortable and distressing, and in some cases, may lead to secondary skin infections due to scratching. Public health efforts focus on education, awareness, and access to effective treatments to manage and prevent infestations.

Cow lice are parasitic insects that infest cattle, causing discomfort and potential health issues for the animals. There are several species of lice that affect cows, primarily divided into two categories: biting lice (Bovicola bovis) and sucking lice (Linognathus vituli, Haematopinus eurysternus, and Solenopotes capillatus). These lice differ in their feeding habits and the types of damage they cause to their hosts.

Appearance and Life Cycle

Biting lice, such as Bovicola bovis, feed on skin debris, hair, and skin secretions, while sucking lice feed on blood. Biting lice are smaller, usually around 2 mm in length, with a flattened, reddish-brown body. Sucking lice are slightly larger, typically 3–5 mm, with a more elongated, bluish-gray body. Both types of lice have specialized mouthparts adapted to their feeding habits.

The life cycle of cow lice consists of three stages: egg (or nit), nymph, and adult. Female lice lay eggs that are firmly attached to the hair shafts of the host. The eggs hatch into nymphs after about 1-2 weeks. Nymphs resemble adults but are smaller and sexually immature. Over the course of two to three weeks, nymphs undergo several molts before maturing into adults. Adult lice can live for several weeks on the host, where they continue to feed and reproduce.

Symptoms and Impact on Cattle

Lice infestations can cause a variety of symptoms in cattle, depending on the severity of the infestation and the type of lice involved. Common signs include excessive scratching, rubbing against objects, hair loss (especially around the neck, shoulders, and base of the tail), and restlessness. In severe cases, lice infestations can lead to anemia, particularly with sucking lice, due to the blood loss they cause. The constant irritation and discomfort can also result in reduced feeding and weight loss, impacting the overall health and productivity of the cattle.

During winter months, lice infestations tend to worsen because cattle's thick winter coats provide an ideal environment for lice to thrive. The cold weather also contributes to the cattle spending more time in close contact with one another, increasing the risk of lice transmission.

Diagnosis and Treatment

Diagnosing lice infestations in cattle typically involves a physical examination of the animal. Lice and their eggs are often visible on the skin, especially in areas where the hair is thin or where the cattle have been rubbing excessively. Using a fine-toothed comb to part the hair can help in identifying lice.

Treatment for lice infestations in cattle involves the use of insecticides, such as pour-on formulations, sprays, or dusts that are specifically designed for livestock. These treatments are applied directly to the animal's skin or coat. In some cases, repeated treatments may be necessary to eliminate all stages of the lice life cycle, especially since some insecticides may not be effective against lice eggs.

Prevention and Management

Preventing lice infestations in cattle requires good management practices. Regular inspection of cattle, particularly during the winter months, can help in early detection and treatment of lice infestations. Isolating new or infested animals from the rest of the herd until they are treated can also help prevent the spread of lice. Additionally, maintaining a clean environment with good nutrition can strengthen cattle's immune systems, making them less susceptible to lice and other parasites.

Lice are a common issue in cattle farming, but with proper management and timely treatment, infestations can be effectively controlled, minimizing their impact on the health and productivity of the herd.