horse anatomy. frog one of the most important, but often neglected structures of the horse’s hoof....

Horse Anatomy

Frog• One of the most important, but often neglected

structures of the horse’s hoof. It should be wide and substantial and made up of thick, leathery material. An unhealthy frog is vulnerable to infection which, if left untreated, can lead to significant loss of structure in the back of the hoof causing severe lameness.

• The frog works in concert with the coronary band, the bars and the sole to provide resistance to distortion of the hoof capsule during the stride.

• Pressure placed upon the frog directly influences the health of the digital cushion above it.

• The frog stay (triangular piece cut out of the sole that the frog sits in) allows independent movement at the heels as the horse lands on uneven ground. The frog also plays a part in protecting the sensitive structures beneath, providing traction, assisting circulation and absorbing shock.

Sole

• The sole is the area inside the white line, but not including the bars and frog. It’s primary function is to protect the sensitive structures beneath the sole.

• However, the outer perimeter of sole also provides support, sharing some of the weight of the horse with the hoof wall.

White line

• The purpose of the Golden Line is to join the sole to the inner wall of the hoof and to seal off the border of the pedal bone to protect it from bacterial infiltration.

• It creates a shallow crease at the bottom of the hoof which fills with dirt, aiding with traction.

• Should not be penetrated by a nail during shoeing.

Inner Wall

• The inner hoof wall is usually white (unlike the outer wall, it does not contain pigment). It is more pliable than the outer wall due to the higher ratio of intertubular horn which bind the tubules together.

Outer Wall

• The outer hoof wall is pigmented and contains a higher ratio of tubules. These tube-like structures grow down from the coronary band in a spiral configuration. It has been suggested that this makes them act like tiny springs, but this cannot happen as there is no space between the coils.

bone growth in the pastern or coffin joint

video

http://video.google.com/videoplay?docid=7742883613355143098

http://www.4act.com/training/play.aspx?cID=143&vID=1944

Digestive System

1. Mouth2. Pharynx3. Esophagus4. Diaphragm5. Spleen6. Stomach7. Duodenum8. Liver, upper extremity9. Large colon10. Coecum11. Small intestine12. Floating colon13. Rectum14. Anus15. Left kidney and its ureter16. Bladder17. Urethra

Equine gastrointestinal anatomyGallbladder?

Fermentation occurs on the Cecum and colon.

Rectal PalpationL side: spleen, pelvic flexure, mesenteric root, L kidney

R side: Aorta, cecum

SI strangulation Cecal tympanyLarge colon impaction

Umbilicus, horse

• Thoracic limb• support the weight of the front

end of its body while using a minimal amount of muscular activity

• helps prevent fatigue of the limb muscles

• transfers weight from the thoracic limb muscles to connective tissue structures that do not tire, namely tendons, ligaments or bone

• Pelvic Limb• supports the weight of the

caudal end of its body allows the other pelvic limb to be placed in a "resting" position: ‘tip toe’

• reduces the amount of energy (the amount of muscular effort is not reduced)

• Pelvic limb: stifle locked, reciprocal mechanism: stifle and hock move in unison; ligament/tendon in distal limb

Lameness Exam - FL

Diagnostic Anesthesia

ASEPSIS IS CRITICAL•Scrub area with surgical scrub (chlorhexidine gluconate or povidone iodine) for a full 5 minutes •Spray area with alcohol (do not allow alcohol to drip from dirty to clean area) •Ensure adequate restraint (keep in mind that the veterinarian is responsible for the safety of everyone involved). Use of a twitch, lip chain or nose chain is indicated. Chemical restraint may be desirable when injecting into a joint to ensure no movement of the horse •Use sterile gloves and an unopened bottle of anesthetic agent •Determine landmarks for injection •Insert need with quick, determined thrust •Obtain joint fluid (if possible) •Attach syringe and inject anesthetic agent - fluid should inject freely, without resistance. If resistance is met, it is advisable to reposition needle, it is probably not intra- articular. •Wait recommended amount of time and re evaluate lameness

Palmar/Plantar Digital Nerve Block

Structures Anesthetized•Navicular bone •Navicular bursa •Distal sesamoidean ligaments •Deep Digital Flexor tendon and sheath •Digital cushion •Corium of frog •Palmar 1/3-2/3 of sole •Palmar pastern and coffin joints •Palmar distal phalanx / wings of coffin bone •Palmar Skin

Dx: Navicular Syndrome, Heel Pain Syndrome, Wing Fractures of P3, Subsolar abscess. +/-Pedal osteitis

Diagnostic Anesthesia

CarpusFetlock Pastern

References

• http://cal.vet.upenn.edu/projects/grossanat/index.htm

• http://www.vet.cornell.edu/oed/horsedissection/Search.asp?Fun=SBM#