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


Back Spasm, Muscles Feel Swollen, Tense or Hard After Exercise


The back musculature of fit, normal horses feels firm and tight. The loin (area of the back behind the saddle) and croup (downward slope behind the top of the hip) should feel smooth, firm, and should not seem rigid or painful when you press on it.

Muscle spasm and hard swelling in the loin or croup area usually occur as a result of exercise under saddle.

In a recently exercised horse, in combination with other signs (reluctant to walk, distressed, profusely sweating), very hard, swollen and sore muscles of the back, loin and croup are compatible with the condition "tying-up" (exertional rhabdomyolysis). Tying-up is a severe and often very painful condition that is a veterinary emergency. Back muscle swelling or spasm can also be indicative of back spasm or injury from an ill-fitting saddle or from other back disorders.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the horse has no appetite and is obviously depressed.
    • If the results of the Whole Horse Exam (WHE) indicate fever (Temp>101F/38.3C), or heart rate greater than 48 BPM that persists an hour after recovery from exercise.
    • If the horse is reluctant to move, along with this sign.
    • If the area seems painful to the touch.
  • 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.

your role


What To Do

If you note this observation but your horse has not exercised recently and seems normal otherwise, this might be normal for this horse. Compare your findings to your other horses and to what you normally observe as "normal" for your horse.

Assess the horse's general health using the Whole Horse Exam (WHE), paying particular attention to heart and respiratory rate, attitude, and whether or not the horse is reluctant to move forward. Note the changes in these signs as the horse recovers following exercise. Press on the back and note the horse's response.

What Not To Do

Do not assess, handle or move your horse if they appear to be in significant discomfort.
Do not give medications, see an improvement, and assume the horse is fine, without discussing this problem with your vet.

your vet's role

Your vet assesses your horse's back in the context of recent activity. Laboratory blood work can be very helpful in ruling out "Tying up" and other muscle conditions.
Questions Your Vet Might Ask:
  • Did you just ride the horse?
  • What is the horse's age, sex, breed and history?
  • What is the horse's heart rate and respiratory rate?
  • Will the horse walk freely in hand or do they resist?
  • How is your horse's attitude and appetite otherwise?
  • What is the horse's exercise and performance history leading up to this?
  • Is the horse showing any signs of abdominal pain (colic)?
  • Did you exercise the horse more than usual?
  • What do you feed the horse?
  • Do you have medications of any kind?
  • 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
more diagnoses

Author: Doug Thal DVM Dipl. ABVP