The clinical signs of PPID stem from the elevated concentrations of hormones in the horse’s blood. The most classic sign is hirsutism, or curly hair that does not shed properly. Other signs include:

  • Excessive sweating
  • Eyes that bulge due to supraorbital fat
  • Frequent drinking
  • Frequent urination
  • Infertility
  • Insulin resistance
  • Laminitis
  • Lethargy
  • Loss of muscle mass
  • Recurrent infections
  • Sinusitis
  • Tooth rot

Horses with signs of PPID may be tested to confirm the diagnosis. It is important to know that no test is completely accurate. The time of year the test is performed also is important when interpreting the results.