This article has been edited and approved by
Karen Coumbe MRCVS, H&H’s veterinary advisor since 1991.
Splints in horses are hard lumps, which are actually bony enlargements found on the side of the horse’s leg between the knee and the fetlock joint, located where the splint bone runs down on either side of the cannon bone.
What are the splint bones?
The medial and lateral splint bones are the remains of the second and fourth digit of the horse’s five-toed prehistoric ancestor. Digits one and five disappeared during evolution, while two and four become splint bones, with the middle digit forming the weight-bearing cannon bone.
The upper two thirds of each splint bone is attached to the cannon bone by dense fibrous tissue called the interosseous ligament. The lower section flares away from the cannon bone slightly and is connected to the surrounding structures by soft tissue. The lower end of the splint bone has a small pea-like “button” which can be felt through the horse’s skin.
In most horses the interosseous ligament gradually changes with age as the splint bones fuse to the cannon bone at around three to four years. This process is normal and has no clinical signs.
Splints in horse [565 words]: Causes | False splints | Diagnosis and treatment | Complications
What causes splints in horses?
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MA VetMB CertEP CertVA MRCVS
Our equine veterinary expert has more than 30 years experience in practice. She is an FEI vet and has attended the past three Olympic and two World Equestrian Games in her role. She has a particular interest in anaesthesia, pre-purchase examinations, ophthalmology and dermatology amongst other clinical concerns. She has been Horse & Hound’s official veterinary advisor since 1991. Karen is part of the Bell Equine team.