University of University of Tennessee College Tennessee College

of Veterinary of Veterinary Medicine – Horse Medicine – Horse Owner Seminar 1-Owner Seminar 1-

22-0522-05Benjamin R Buchanan, DVMBenjamin R Buchanan, DVM

Resident Large Animal Internal Resident Large Animal Internal MedicineMedicine

Resident Veterinary Emergency and Resident Veterinary Emergency and Critical CareCritical Care

Guide to the Guide to the Equine GutEquine Gut

Normal Equine Normal Equine Gastrointestinal Gastrointestinal

AnatomyAnatomy

DivisionsDivisions Oral CavityOral Cavity EsophagusEsophagus Small IntestineSmall Intestine

ProximalProximal MidMid Distal Distal

CecumCecum Large ColonLarge Colon

Transverse Transverse ColonColon

Small ColonSmall Colon RectumRectum

Oral CavityOral Cavity

Oral CavityOral Cavity

Oral CavityOral Cavity

Oral CavityOral Cavity

Pharynx and Pharynx and Guttural PouchGuttural Pouch

PharynxPharynx EpiglottisEpiglottis ArytenoidsArytenoids Opening to Opening to

EsophagusEsophagus GPGP

Nerves control Nerves control swalloingswalloing

EsophagusEsophagus

Connects oral cavity to stomachConnects oral cavity to stomach Valve where it travels from thorax Valve where it travels from thorax

into stomachinto stomach Swallowing unconsciously controlledSwallowing unconsciously controlled Covered by squamous tissue Covered by squamous tissue

MesenteryMesentery

Long sheet of Long sheet of tissuetissue

Connects Connects intestines to body intestines to body wallwall

Carries blood Carries blood vessels and nervesvessels and nerves

StomachStomach

Covered by two Covered by two types of tissuetypes of tissue

Squamous tissueSquamous tissue Mucosal tissueMucosal tissue Anchored in the Anchored in the

cranial left cranial left abdomenabdomen

Digestion of food Digestion of food materialmaterial

Small IntestineSmall Intestine ProximalProximal

DuodenumDuodenum Connection for liver Connection for liver

and pancreasand pancreas Digestion of food Digestion of food

materialmaterial Short mesenteryShort mesentery

MidMid JejunumJejunum Digestion and Digestion and

absorptionabsorption Long mesenteryLong mesentery

Small IntestineSmall Intestine

DistalDistal IleumIleum Controls rate of Controls rate of

flow into flow into cecum/coloncecum/colon

Tape wormsTape worms Short mesenteryShort mesentery

CecumCecum

AppendixAppendix Fermentation and fiber digestionFermentation and fiber digestion Base and apexBase and apex 8-10 gallons fluid and gas8-10 gallons fluid and gas Anchored at base by mesenteryAnchored at base by mesentery

Large ColonLarge Colon

Modification of ascending colonModification of ascending colon Travels from right flank to liver to Travels from right flank to liver to

left flank back to liver back to right left flank back to liver back to right flankflank

Anchored on right by short Anchored on right by short mesentery, free on leftmesentery, free on left

Ferementation and fiber digestionFerementation and fiber digestion

Transverse ColonTransverse Colon

Short connection Short connection of large colon to of large colon to small colonsmall colon

Short mesenteryShort mesentery

Small ColonSmall Colon

Descending colonDescending colon Water Water

reabsorptionreabsorption Fecal storageFecal storage Long mesenteryLong mesentery

RectumRectum

Abdominal and extraabdominalAbdominal and extraabdominal Short mesentaryShort mesentary Fecal storageFecal storage Route for abdominal palpationRoute for abdominal palpation

Glass HorseGlass Horse

QuestionsQuestions