Horse GI System Flashcards
What kind of fermenters are horses
Hindgut
Path of digesta/food through horse stomach
Mouth —> esophagus —> stomach —-> duodenum —> jejunum —> ileum —> cecum —> right ventral colon —> sternal flexure -> left ventral colon —> pelvic flexure —> left dorsal colon —> diaphragmatic flexure —> right dorsal colon —> transverse colon —> descending/small colon —> rectum/anus
Bands of the colon are called
Taenia
Are there taenia in small intestine
No
Name of taenia in ileum
Antimesenteric band
How many bands/taenia in cecum
4
number of taenia: ventral colon, pelvic flexure, dorsal colon, small colon
Ventral - 4
Pelvic - 1
Dorsal - 3
Small - 2
Rugae definition
Series of ridges produced by folding of wall of organ =stomach
Haustra:definition, how formed
Small segmented pouches of bowel separated by Haustral folds
Formed by circumferential contraction of inner muscular layer of colon
How is outer longitudinal laye r of colon organized
Into 3 bands/taenia coli running from cecum to rectum
What side of the body are duodenum and cecum on
Right
Esophagus: function, unique feature
One way transport = no vomiting
Stomach function
Enzymatic breakdown
Small intestine function
Digest rapidly available carbs and protein
where/when do horses obtain most of their protein during digestion process
Digestion in foregut
Cecum function
Where cellulose is broken down
*carbs and proteins in cell walls of plants that escape digestion in small intestine
Functions of colon
Reabsorption of water
Some fermentation
Function of descending/small colon
Form fecal balls
Where does microbial fermentation occur (2)
Cecum
Colon
Hindgut fermentation products (3)
CO2
Methane
Volatile fatty acids
Hindgut vs foregut fermentation
Foregut = enzymatic
Hindgut = microbial
Microbial fermentation in hindgut allows horses to
Breakdown cellulose
What happens to hindgut fermentation products
Absorbed through intestinal wall
3 volatile fatty acids: fermentation products
Proprionate
Acetate
Butyrate
Proprionate
VFA used for Glucose production
Acetate
VFA converted to acetyl Coa —> used for immediate energy or fat synthesis
Butyrate
VFA converted to acetyl CoA for energy or fat synthesis
Disadvantages of hindgut fermentation (5)
-less efficient
-already absorbed most nutrients in foregut so nitrogen poor material entering hindgut promotes LESS microbial growth
-passage more rapid through hindgut
-less efficient at absorbing vitamins and proteins
-not digestible protein present in microbes = LOST
Microbiota consists of (3)
Bacteria
Fungi
Protozoa
Which phylum constitutes majority of microbiota
Fermicutes
Colic definition
Abdominal pain of any kind
Colic: behavioral signs
Sweating, pawing, tachycardia, tachypnea, rolling, stretching out, biting or looking at sides, kicking at abdomen
Margo plicatus
Separates upper squamous stomach from lower glandular stomach
2 types of equine gastric ulcer syndrome
Equine squamous gastric disease
Equine glandular gastric disease
Enteritis definition
Inflammatory disease of small intestine (>3mm)
Acute enteritis: location, clinical signs
Proximal
Fever, reflux, leukocytosis, colic that resolves with decompression
Chronic enteritis: clinical signs
Inflammatory bowel syndrome, neoplasia
Weight loss
Small intestine Impaction definition
Simple obstructive lesion of small intestine
3 types of small intestine impactions
Ileal impactions
Adhesions
Ascaridiasis
Most common location of impaction in small intestine
Ileum
2 Causes of ileal impactions
Feeding coastal Bermuda hay
Tapeworm infestation
2 Clinical signs of small intestine strangulations
Severe pain
Serosanguinous belly tap
Strangulating lipoma
Form on stalks in mesentery
Epiploic foramen entrapment
small intestinal strangulation
Potential space: liver, caudal vena cava, portal vein
Intessusception
type of small intestinal strangulation
Ileocecal tapeworms
Inguinal hernias occur in what kind of horses
Stallions
4 types of large colon impactions
Pelvic flexure
Sand impactions
Enteroliths
Cecal impaction
Most common location of large colon impaction
Pelvic flexure: ventral colon to dorsal colon
Sand accumulates in what 3 regions of large colon
Ventral colon
Right dorsal colon
Pelvic flexure
Enteroliths
stones that can cause obstruction
Associated with legume hay with high calcium (alfalfa)
Right dorsal colon/transverse colon
Cecal impaction
Associated with orthopedic surgical disease
More often a secondary condition
2 types of large colon displacements
Nephrosplenic entrapment/left dorsal displacement
Right dorsal displacement
Nephrosplenic entrapment: definition, can become what
Colon hangs between left kidney and spleen
Can become left dorsal displacement
Right dorsal displacement
When pelvic flexure flips
Colitis definition
Inflammatory disease of large colon
3 etiologies of colitis
Infectious = salmonella
Verminous = encysted small strongyles
Caustic = sand
Colon volvulus: definition, location
Severe, unrelenting abdominal pain
Gross dissension of abdomen
At mesenteric attachment of colon to dorsal body wall involving cecum and large colon
*obstruction caused by twisting of above areas
Meconium impactions: who affected, location
Foals
1st poop when born gets stuck in descending colon
Peritonitis: definition, causes, effect
Inflammation of peritoneum
Recent abdominal surgery, strongyles, infiltrative bowel disease, internal abscesses
Ileus
Tapeworms cause what 3 things
Ileocecal intussusception
Cecocolic intussusception
Typhilitis
Ascarids cause what kind of impaction
Small intestinal
Large strongyles can cause what kind of colic
Thromboembolic
Cranial mesenteric aneurism
