What you see. The starting point for addressing any equine health related issue is your observation.


Gums have Dark Red Line above Teeth


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 pink membrane inside the nostril, the whites of the eyes, and the pink inner vulvar membranes of mares. That said, the simple act of evaluating the color of your horse's gums is a very important skill.

When a horse's gums are pink but have a dark line at the gum-line of the incisor teeth this can be a sign of toxemia, dehydration and other abnormal circulatory states. In the veterinary world, this is often called a "toxic line".

This appearance can also be confused with normal. Keep in mind that horses (especially older horses) with gingivitis, periodontal disease, or EOTRH will also have a red line at the gum margin.

  • 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 results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
You also might be observing
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your role


What To Do

When in doubt, assess your horse's general health using the Whole Horse Exam (WHE) and call your vet to discuss your findings and concerns. If you see a sign like this, always compare the appearance of one side to the other side, and to the gum color of your other healthy horses. Always consider the state of the horse's general health.

your vet's role

Your vet may advise you to take a "wait and see" approach or suggest that they examine your horse, depending on the presence of absence of other signs or problems.

A careful physical exam may help your vet generally define the nature of the problem. Blood work can be helpful in identifying more subtle disease states.
Questions Your Vet Might Ask:
  • Does the horse appear normal other than this finding?
  • Do you notice other signs of a problem?
  • Does the horse's appetite and attitude seem normal?
  • Have you looked at both sides of the horse and accounted for different light?
  • Have you compared the appearance in this horse to that in your other horses?
  • What is the Capillary Refill Time (CRT)?
  • Does the "skin pinch on the shoulder" test look normal?
  • What is the horse's heart rate and respiratory rate?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
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Author: Doug Thal DVM Dipl. ABVP