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


Biting at Side or Body


This observation is seen under several circumstances. Horses that have itchy or irritated skin (a common cause is insect hypersensitivity or irritation) will often nip and bite at the affected area. Horses in abdominal pain (colic) often look at their sides (flanks) and sometimes will bite their skin there.

Rare behavioral syndromes that involve self-trauma and self-mutilation also may cause this behavior to occur. Horses affected by these syndromes can bite viciously at themselves, causing severe wounding. There usually is a history of other behavioral abnormalities occurring along with this behavior.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If you are convinced this is a sign of colic (abdominal pain).
    • If you notice signs of colic, along with this sign.
    • If the behavior seems extreme, or the horse seems to be in distress.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the behavior continues but the horse has good appetite, attitude and shows no other signs of colic.
  • Code Green

    Contact Your Vet to Obtain Useful Advice & Resources
    • If this seems mild or occasional and the horse seems normal otherwise.
You also might be observing
Very Common
Less Common
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your role


What To Do

Assess your horse's general health using the Whole Horse Exam (WHE). Inspect the sheath, udder and lower belly for signs of swelling, hair loss, scaling or scabbing. Look carefully at the rest of the horse for hives, which would suggest an allergic problem. Check the area carefully for insects, which tend to cause irritation.

Consider whether anything has changed in the environment. For example, have you applied something topically or changed feed or bedding? If you suspect the cause is irritation or allergy (flies, midges or mosquitos), try to solve the problem with mild insect repellents and management changes.

If this behavior continues or worsens despite your efforts, or your horse is exhibiting other signs of illness or abnormalities, contact your vet with your findings and concerns.

What Not To Do

Do not use harsh chemicals. Application of these products may worsen itchiness or irritation. If you shampoo seemingly irritated areas, always be sure to rinse well.

your vet's role

Your vet carefully evaluates the nature of the behavior and focuses on the area that the horse is biting at, looking for the factors discussed above. If there does not seem to be an irritant causing the behavior, vets rule out less common reasons for it using diagnostic tests.
Questions Your Vet Might Ask:
  • Do you notice signs of abdominal pain (colic)?
  • Do you notice swellings on the skin?
  • Are you seeing hair loss or hives?
  • When did you first notice this behavior?
  • What is the horse's age, sex, breed and history?
  • 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
Less Common
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Treatments Your Vet May Recommend

A way to resolve the condition or diagnosis. Resolving the underlying cause or treating the signs of disease (symptomatic treatment)

Very Common
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Author: Doug Thal DVM Dipl. ABVP