Why Is My Horse Losing Hair in Clumps?

It is alarming to suddenly discover that your horse is losing hair in clumps. In addition to insect bites, allergies and skin infections, there are a number of other disorders that can specifically cause a horse to shed hair.

  1. Queensland Itch

    • Queensland Itch is the most common form of contact dermatitis that triggers hair loss in horses; it is due to an allergy to gnat saliva. Constant rubbing to subdue the intense itch typically causes hair to mat and fall out in clumps.

    Rain Scalds

    • Rain scalds, a fungal infection, causes hair to mat in clumps that resemble large drops of water, which eventually fall out and leave bare spots. As the name implies, this disorder occurs during periods of heavy rain.

    "Bob-tail" Disease

    • "Bob-tail" disease is characterized by excessive hair loss from the mane and tail and is indicative of selenium toxicity.

    Ringworm

    • Ringworm is another type of fungal infection, characterized by a telltale oval and scaly patches of skin from which clumps of hair are easily lost. It is more common in fall and winter and typically affects the girth of the animal.

    Seborrhea

    • Seborrhea resembles dandruff except that clumps of hair are lost while the horse sheds dry, scaly patches of skin.