E

Easy keeper
A horse that keeps weight on easily.

Elbow
The joint on the foreleg between the joint of the shoulder and the knee. 

Electrolyte
A salt replacement often used for horses who work hard. Electrolytes are necessary in many of the horse's body functions.

Embryo
The fetus in it's early stages of development.

Endoscope
A fiberoptic instrument for viewing inside of body cavities.

Engage
The shifting of weight to the hindquarters, enabling the horse to move forward with impulsion.

Engagement
The result of engaging the hindquarters. Includes the back and entire longitudinal distance of the horse.

English
A discipline or style of riding from England. 

Equestrian
A rider or horseman, usually referred to english riding disciplines.

Equine encephalomyelitis
A viral disease of the horse. Affects the brain and spinal cord.

Equine influenza
A viral disease of the horse. Affects the respiratory tract.
Upper respiratory viral diseases in the horse

Equine Protozoal Myeloencephalitis
A serious and 'difficult to diagnose' disease caused from opossum feces. The feces contain sproracysts, which the horse comes into contact with when grazing, eating contaminated feed or water. These sporacysts attack the central nervous system, causing neurological damage and death.

Equine viral arteritis
A viral disease of the horse. Affects all horses but can cause abortion in mares.

Equine
Name for the family of horses, asses and zebras.  

Equitation
The level of riding as it pertains to the rider: seat, balance, hands, aids.

Ergot
A horny growth behind the fetlock joint.

Evade: Evading: Evasion
To avoid an aid, most commonly reffered to the bit.

Eventing
A combined training of dressage, cross country courses and stadium jumping.   

Extention
To lengthen the stride without the stride occuring faster, and keeping the same cadence.

Extensor tendons
The tendon that's attached to all the bones in the horses foot except the navicular bone.

Extensor
The muscle that opens the angle of the joint.