Skin Lesions on Cows

Like humans, cows are susceptible to infection from bacteria, fungi and viruses. Some infections produce visible and characteristic skin lesions. Knowing what type of infection is affecting your cattle allows you to react appropriately. If you notice skin lesions on a cow, separate it from other animals and contact a veterinarian for a professional diagnosis.

  1. Ringworm

    • Ringworm is a fungal infection that affects a cow's skin and is not considered a serious illness. It causes crusts to form and may cause hair loss. The name "ringworm" comes from the ringlike appearance of the lesions. Ringworm is commonly found on the head and around the eyes, but it can appear anywhere on a cow's body. This fungal infection spreads through physical contact between cows and contaminated equipment, such as rope and utensils. Ringworm can also spread to humans. Cows subjected to high humidity, poor nutrition and close quarters are more susceptible to infection. Cows with poor immune systems and those that do not get enough sunlight are also at risk.

    PLSD

    • PLSD is a virus that insect bites cause and is spread through infected saliva. The virus is a superficial condition that does not affect a cow's health. It causes oval or circular plaques to form on the skin. The plaques are hard and have red edges. Three days after the appearance of the plaques, they enlarge and form a brown crust in the center. After two weeks, the plaques peel off, revealing new skin.

    Dermatophilosis

    • The bacteria dermatophilus congolensis causes dermatophilosis, also called rain scald. It causes scabs to form on the muzzle, ears and withers, but it can cover up to half of a cow's body. Hair loss and hair matting also occur. Dermatophilosis is spread through physical contact between animals and through contaminated equipment. A cow's condition may worsen if it lives in a humid or wet environment. Keep infected animals dry, separated from other animals and exposed to sunlight.

    Pseudocowpox

    • Pseudocowpox, also known as milker's nodules, is a mild skin infection that affects the udder and teats. Infected cows are hard to milk due to the location of the infection. A virus causes pseudocowpox and affects cows worldwide. Lesions start out as small, red papules and may turn into scabs. The scabs fall off seven to 10 days after first appearing, leaving a ring or horseshoe area behind. The virus can spread to humans, causing itchy purplish-red nodules to form, usually on the hands and fingers.