Equine Skin microbiology

Skin conditions are very common in horses and may result from bacterial, fungal or parasitic infection. Diagnosis can rarely be made on the appearance of the lesion alone as many skin infections present with crusting of the skin, hair loss and may or may not cause the animal to scratch.

Infectious causes of skin conditions include:
  • Dermatophytosis (ringworm)
  • Dermatophilosis (rain scald)
  • Staphylococcal folliculitis
  • Corynebacterial folliculitis
  • Malassezia dermatitis
  • Chorioptic mange
  • Sarcoptic mange
  • Psoroptic mange
  • Lice
Good sample collection is vital in the interpretation of skin microbiology results as many bacteria and fungi may be found as normal commensals on healthy skin. Crusts from the lesion are the best sample for detection of Dermatophilus zoospores while a swab from a fresh pustule or of exudate from underneath a fresh crust is the preferred sample for bacterial culture. Skin scrapes and hair plucks from the edge of the lesion are the preferred samples for detection of parasites and ringworm.