Hoof Anatomy Equine ½ 2014

 “No foot, no horse”  Feet are the foundation of the horse  What are hooves designed for?  Support Weight  Replenish Itself  Absorb Shock  Provide Traction  Conduct Moisture  Assist in Pumping Blood Structure & Function

 Conformation of the horse greatly affects?  Foot function  The small bones in the foot must be:  Light enough to:  Allow the horse to move without fatigue  Strong enough to:  Resist shock and compression of weight- bearing Structure & Function

 How does the foot aid in concussion?  Acts as an overall shock-absorbing mechanism  What affects the amount of concussion?  Angle of shoulder and pastern  Elasticity of the lower leg ligaments  Elasticity and movement of hoof wall Structure & Function

 Why is it important that the hoof is proportional to the horse’s body size?  Ideal distribution of body weight over the foot’s laminar surface  So hoof can expand normally during movement Structure & Function

 Hoof size is apparently highly heritable:  Correlates with bone growth  Some breeds select for small feet for aesthetic purposes  Also influenced by nutrition Structure & Function

 Hoof can be divided into two areas  Sensitive  Insensitive  Sensitive areas provide:  Nourishment and promote growth  Contain blood vessels and nerve endings  Insensitive areas provide:  Support  Protection Structure & Function

External Parts of the Hoof

 Inside the white line  Does NOT include frog and bar  Primary function  Protect sensitive structures beneath sole  Perimeter provides support (share with hoof wall)  Usually arched Sole

 Not actually white (yellowish)  Commonly mistaken for inner wall which is white  Function  Join the sole to the inner wall of hoof  Seal off the boarder to prevent bacterial infection  Creates ridge to increase traction White Line

 Inner Hoof Wall  White, does not contain pigment  High moisture content which allows inner wall to stretch  Protect internal structures from shock  Outer Hoof Wall  Colored  Grows down from cornet band  Protects hoof and absorbs shock Inner and Outer Wall

 Extension of wall which runs along frog  Function  Controls movement at back of hoof  Adds strength to heel  Protects from distortion Bars

 Misleading, refers to heels  Function  Take initial impact of horse’s stride  Absorbs and displaces shock  Balance is important Angle of the Bar

 Grove that runs along frog  Needs to be cleaned diligently  Thrush Collateral Groove

 Most important structure  Wide, thick and leathery  Works with  Coronary band  Bars  Sole  Digital Cushion Frog

 Function  Works as a pump  As horse steps on hoof, pressure is applied to the frog (hits digital cushion) and pump blood up the leg  Provides traction  Absorbs shock  Protects internal structures Frog

Coronary Band & Periople Coronary Band  Sits at top of Hoof Wall  Functions  Protects outer hoof wall  Very strong and acts as support band for entire hoof during movement Periople  Protective covering for newly formed hoof  Soft  Covers hoof wall

Internal Structures

 Provides strength and stability to hoof  Various tendons and ligaments attach  Connected via laminae Coffin Bone

 Tiny bone  Sits behind coffin bone  Deep digital flexor tendon passes over navicular bone  Horse “has navicular” Navicular

 Digital Cushion  Venous Plexuses  Insensitive Laminae  Sensitive Laminae Internal Structures

 Sits behind coffin bone and above frog  Function  Absorb shock and “pump” blood Digital Cushion dajdklad.gif

 5 venous plexuses  Solar  Digital Cushion  Lateral Cartilage  Lamellae  Coronary Venous Plexus _mechanism_movie1.gif

Venous Plexus

 Hold the hoof wall to the coffin bone  Filled with blood vessels and nerves  Sensitive and Insensitive laminae interlock  Very strong bond  Make up white line (at bottom of hoof) Laminae

Sensitive  Attached to coffin bone  Filled with blood and nerve endings Insensitive/ Horny  Closest to hoof wall  Attached to the hoof wall

Laminae

Laminatis

Shock Absorption  When the horse takes a step:  The sole descends and flattens slightly  White line absorbs impact as the wall moves out  Laminae diminishes concussion coffin bone  Transfers weight and redirects forces between hoof and skeleton