Horse Side Vet Guide ®

Equine Health Resource

Neck Swelling

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 this problem seems severe and has come on suddenly.
  • If you think your horse may have sustained a fracture or other severe injury.
  • If you notice apparent wobbliness or weakness, in addition to this sign.
  • 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.
  • If the swelling is mild or moderate, and not increasing rapidly.
  • If the condition does not seem to be causing pain or other problem.

When considering swelling of the neck, it helps to roughly divide the neck into thirds, and to know the very basic anatomy of the regions. The upper region, under the mane, is mostly composed of ligament tissue. The middle third is the flat, muscular region commonly used for intramuscular injection, and the lower region contains the spinal column and jugular groove. There are important structures that run through the lower region, including the jugular vein, carotid artery and major nerves. Injury to these structures can be serious and so swelling here must be taken seriously. See the Quick reference image of head and neck.

Swelling of the upper region is rare and is most common after a misplaced, high IM injection. The middle region swells most commonly as a result of injection reaction. The lower region swells with spinal column injury, and any misplaced IV injection. Damage to the jugular vein can result in swelling here as can heart failure with blood backup into the jugular vein. Fractures and injury of the spine can be associated with swelling here too. Damage to the trachea allows air to escape and become trapped under the skin. This causes a specific type of crackly, soft swelling. Traumatic injury is possible in any region.


Assess the horse’s general health using the Whole Horse Exam WHE), paying particular attention to rectal temperature and heart rate. Gently examine and press on the area. Is it hard or soft, hot, or swollen? Does your horse exhibit a pain response when touched? Take a photo of the swelling. Share it, and your findings and concerns with your vet.


Your vet assesses overall health, considers the horse’s history and carefully assesses the area and the involved anatomy. Ultrasound and x-ray are commonly used diagnostics to help assess this area.

Author: Doug Thal DVM Dipl. ABVP


We're not around right now. But you can send us an email and we'll get back to you, asap.