ANATOMY

• Horse


  • Equidae - Family of horses (equids)
  • A group of running, herbivorous mammals characterized by the reduction in size or complete absence of one or more side toes on each foot
  • The only living family are characterized by only one functional digit (middle digit), thus the foot is actually a single fingertip
• Anglo-Saxon word "hors"


  Meaning swiftness
• "No Foot, No Horse" - raised for its ability to run
• Muscles of horse


  • Made up of a lot of fibers and tendons
  • Most are pennate
• Perissodactyla


  • Usually inaabot ng 22 hands
  • 1 FUNCTIONAL carpal and tarsal, and metacarpal and metatarsal
  • Splint bones - non-functional/vestige metacarpals
• Kingdom, Phylum, Class, Clade, Order, Family, Genus of horse

  • Animalia
  • Chordata (Having spine/vertebral column)
  • Mammalia - (mammal glands, warm-blooded)
  • Ungulata / Ungulates
  • Perissodactyla (odd-toes) & Artiodactyla (even-toes)
  • Equidae (Horse-like animals)
  • Equus (+ caballus)
• Ungulates


  • Camel, pigs, zebra, giraffe
• Perissodactyla animals


  • Horses, zebra, donkey, tapir
• Artiodactyla animals


  • Pigs, ruminants, hippopotamus, camel
• Evolution of horse


  1. Condylarth

  2. Hyracotherium (Dawn Horse)

  3. Mesohippus

  4. Merychippus

  5. Pliohippus

  6. Equus
• Hyracotherium (Dawn Horse)


  • Around 4 ½ hands or 0.4 meters in height
  • Appeared around 60 million years ago
  • Relatively small, varying from the size of a fox terrier to that of a Shetland pony with padded feet and elongated upper toe bones
  • Forefeet – 4 toes (digits 2, 3, 4, 5)
  • Hindfeet – 3 toes
  • 4 metacarpals and metatarsals
  • 4 functional digits

  
• Mesohippus


  • Larger horses
  • Oligocene period
  • Feet are still padded but all had only three toes

  
• Merychippus


  • Grazing horses
  • Miocene period
  • Having the spring foot mechanism and even shorter minor toes
  • Shared the characteristics of the modern horse

  
• Pliohippus


  • First one-toed species
  • Pliocene period
  • Very much like the modern horse

  
• Equus


  • Only remaining living one-toed species belonging to the Equidae family
  • 3 members: Horses – Equus Caballus, Ass or donkey – E. asinus, Zebras – E. burchelli, E. grevyi, E. zebra
  • 1 metacarpal and metatarsal
  • 1 digit
  • Efficient for racing/running
  • Less friction
• Origins of horses


  • Wild horse of Asia - Oriental light-legged horses, Thoroughbred originated from these stocks
  • Wild horse of Europe (European forest type) - Shire, Belgian Horse, Shetland pony
  • The Tarpan - more smaller, Russian, Extinct in the wild
  • Przewalski Horse (Equus ferus) - Distinctly yellowish with dark stripe on the shoulders and down the middle of the back
• Origins of donkey


  • Descended from wild donkey (Nubian wild ass) of North Africa
  • First domesticated in Egypt and spread to the southwestern Asia
  • Bred for their hardiness and docility
  • Used by travelers to carry their commodities
• Uses of horses


  • Military purposes
  • Recreation and Sport
  • Agricultural and commercial pursuits
  • As a source of food
• White muscles


  Fast-twitch muscle
• Red muscles


  Slow-twitch muscle
• White muscles


  • A lot of energy sources
  • A lot of GLYCOGEN (nagiging glucose)
• Red muscles


  • Energy source is in the whole body
  • Do not reach tetany
  • Lots of myoglobin (carries a lot of oxygen = less buildup of lactic acid that causes cramp)
• Usually use Layman's Term not anatomical term, e.g. "knee joint of the horse" not "radiocarpal joint of the horse"
• Muzzle


  • Soft/velvet compared to dogs
  • Combination of nose +upper lip - used for restraint (hinahawakan 'yung nguso o labi para makatulog 'yung kabayo)
  • Lip twitch - nagre-relax 'yung kabayo
  • As horse ages, they get white hairs around their muzzles and white rings around their eyes
• Mane


  Hair at the back (nape)
• Bangs


  Hair at the front, known as forelock
• Poll


  • Highest point of the horse's head
  • Nuchal crest of the skull (short ridge at the end of the skull)
  • Nuchal ligament
  • Nuchal bursa - responsible for the heaviness of horse's head
  • Poll evil - Bursa ruptures due to trauma which cause infection or pus in the poll

  
• Bridle Path


  Where bridle attaches
• Crest


  Dorsal midline of the neck
• Flanks


  Side/gilid ng kabayo
• Withers


  • Highest point of shoulder of the horse (relates to spinous process of thoracic vertebra and scapular cartilage of scapula)
  • Where height is measured in HANDS (app. 4-5 inches)

  
• Loin


  Back of the horse, especially the muscular portion

  
• Hip


  • Pelvic bone is in contact/articulated with the spine of the horse
  • Croup - represented by the spine of os sacrum, highest point of hindlimb
  • Dock - also known as tailhead
• Shoulder /Arm (Brachium)


  Not palpable as it is attached to the body, only the point of the shoulder is visible (where the scapula is articulated with the humerus), elbow is located here
• Forearm (Antebrachim)


  Knee - located in the forelimb (radiocarpal joint), Cannon - located after the knee, the 1 metacarpal left
• Foot


  • Technically includes carpal and metacarpal bones, but in horses, foot = digits only (prox, mid, and distal phalanges)
  • Includes fetlock, pastern, coffin, coronet, hoof

  
• Chestnut


  Vestige from the carpal pads of the horse, pads not in contact with ground but have keratinized tissue due to evolution, can be used for a "chestnut pull" to check training
• Ergot


  Vestige from the metacarpal pads of the horse, much smaller mass of point keratinized tissue found in the medial side of the horse's pad

  
• Barrel


  Large part of the majority of the body, barrel-like structure
• Flanks


  Lateral portion of the abdominal cavity