Horse Side Vet Guide ®

Equine Health Resource

Purple, Red or Dark Spots on Gums or inside Nostril

Code Red - Call Your Vet Immediately, Even Outside Business Hours

Code Orange - Call Your Vet at Their First Available Office Hours

Code Red - Call Your Vet Immediately, Even Outside Business Hours

  • If the results of the Whole Horse Exam (WHE) in the resting horse indicate fever (Temp >101F/38.3C) or heart rate greater than 48 BPM.

Code Orange - Call Your Vet at Their First Available Office Hours

  • If the problem is subtle or slowly changing.
  • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.

There are a few areas on the body that provide important information regarding the state of a horse’s circulatory health. These areas include the gums, the whites of the eyes, and the pink inner vulvar membranes of mares. Another window into the horse’s health is the pink membrane visible inside the horse’s nostril. The simple act of evaluating the color of this area is a very helpful skill.

Some diseases cause inflammation of the blood vessel wall, cause vessels to leak blood into the tissues (vasculitis). In horses with vasculitis, this area to appears purple, red, dark spotted or blotched. Examples are clotting disorders and disorders of the blood vessel walls themselves. This particular finding can be especially obvious in the glistening pink membrane inside the nostril. Keep in mind though that purplish discoloration of the gums can also be traumatic (bruising of the tissues).


Assess your horse’s general health using the Whole Horse Exam (WHE) and reassess the color of their gums or nostrils after gently wiping the membranes off with a thumb or paper towel. Compare the appearance here to the gum color. Look for similar blotches there and on the whites of the eyes. Look for evidence of problems or abnormalities elsewhere. Especially look for swelling of the lower limbs, a finding that can be seen with blotching of the gums and can indicate leaky blood vessels (vasculitis).

Keep in mind that it takes some practice to recognize what may be abnormal. It is easy to confuse the normal, webbed appearance of the network of small vessels inside the nostril with an abnormality, especially in foals. Also, traumatic injury can occur here too, and can cause a similar appearance. Could the horse have suffered trauma to this area?

Share your findings and concerns with your vet.


In vet speak, red or purple spots on the mucous membranes are called petechia, and they are a sign of vasculitis (inflammation or damage to blood vessels). Your vet looks for other signs of vasculitis and performs tests that rule out the common causes. But petechia can also appear similar to bruising from trauma. The appearance of the condition and presence or absence of other signs helps differentiate between these.

Author: Doug Thal DVM Dipl. ABVP


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