The mucous membranes are the lining of a horse's or pony's eyelids, gums, and the inside of the nostrils. The colour of the mucous membranes is also an excellent indicator of blood circulation. A good indication of a healthy horse or pony is that his or her gums should be slightly paler than those of a human being. However if thes gums are very pale, bright red, greyish blue or bright yellow, call your vet immediately.

Colour of Mucous Membranes:

Moist Pink: Healthy normal circulation.
Very Pale Pink: Capillaries contracted, indicates fever, blood loss or anaemia.
Bright Red: Capillaries enlarged, indicates toxicity or mild shock.
Grey or Blue: Severe shock, depression and illness.
Bright Yellow: Associated with liver problems.