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


Foul Odor from Mouth or Face, Bad Breath


Horses with problems involving their mouths often have bad breath or a foul odor emanating from their head. Wounds in the mouth, periodontal disease and feed pockets, loose teeth, abscessed teeth, and ulcers in the cheek from dental overgrowth or retained caps all can result in a variety of pungent and unpleasant odors. Horses with certain types of abscesses in the throat or rear of the mouth can have a bad odor around their mouths.

Sour breath and sour mouth can be associated with intestinal obstructions that may cause signs of abdominal pain (colic). The odor is due to the buildup of excretory products that normally pass out through the equine digestive tract. The same applies to horses experiencing kidney failure. In that case, buildup of toxins normally excreted in the urine causes an odor that can be detected in the breath and around the mouth.

  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the horse seems to be having difficulty eating, in addition to showing this sign.
  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • If you consider this a chronic and relatively mild problem that is not changing rapidly.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.

your role


What To Do

If you notice an unusual odor coming from your horse's mouth or face, assess your horse's general health using the Whole Horse Exam (WHE), look for other signs of illness or disease, and assess their mouth (wear gloves). Contact your vet to discuss your findings and concerns.

your vet's role

Your vet assesses general health and does a careful oral and dental examination to determine the cause of the odor. Treatment will depend on their findings.
Questions Your Vet Might Ask:
  • When did you first notice this?
  • Does the horse seem to be having difficulty eating or dropping feed?
  • How old is the horse?
  • Do you notice a nasal discharge?
  • What are the results of the Whole Horse Exam (WHE)?
  • How is your horse's attitude and appetite?
  • Did you attempt to look in the horse's mouth?
  • Do you notice odor in the mouth?
  • What did you see when you looked in the horse's mouth?

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
Less Common
more diagnoses

Author: Doug Thal DVM Dipl. ABVP