Equine dentistry/GI

Question 1

VT role in equine dentistry

Answer 1

Client education
Sedation
Restraint
Know how to hold head and gag
Carefully hold tongue out of the way
Record keeping
Managing equipment

Question 2

Hypsodont teeth

Answer 2

Long crowns with much tooth in reserve below gum line
Continuous eruption
Enamel folds supported by cementum and dentin

Question 3

Infundibulum is

Answer 3

“cups” are depressions on the occlusal surface of the teeth filled with cementum – a common location for cavities to develop.

Question 4

Equine dental formula

Answer 4

Birth–9 months deciduous: 2 (i3/3, c0/0, p 3/3 ) = 24
Mature horse: 2(I 3/3, C (1)/(1), P 3(4)/ 3(4), M 3/3) = 36- 44
Mares often have small or no canine or wolf teeth therefore some numbers in brackets.

Question 5

Curvature of Spee is

Answer 5

natural upward curve of the back teeth with the mandible

Question 6

Curvature of Wilson

Answer 6

the occlusal plane of the caudal teeth across the arcade

Question 7

Clinical signs of dental disease in horse

Answer 7

“Quidding”
Difficulty chewing, washing mouth out in water bucket
Weight loss
Nasal discharge
Facial swelling
Malodorous breath
Issues with bridle/bit

Question 8

Floating horse teeth is

Answer 8

Sharp points develop along the outside edges of upper cheek teeth and inside edge of lower cheek teeth most commonly as the maxilla and its teeth are wider than the mandible.
In nature these likely break off but less so in housed horses fed “softer” feed.
Sharp points may lacerate cheeks/tongue and make wearing a bridle/halter uncomfortable.
Because teeth are continuously erupting and wearing – any place teeth do not meet in occlusion in the mouth is prone to overgrowth.
If an adult horse has normal occlusion a dental examination/float is often performed annually as part of a “herd health” visit.
In young horses losing deciduous teeth or any horse with missing or maloccluded teeth every 6 months may be recommended

Question 9

Young horses are likely to get what dental diseases

Answer 9

Young horse issues up to 5 years of age deciduous teeth shedding and adults coming in:
Lampas
Retained deciduous ”caps”
Eruption cysts (bumps)
Palpable lumps along ventral ramus of mandible due to eruption of adult cheek teeth
Resolve on their own.
May be painful to palpation

Question 10

Common dental disease in horses of any age

Answer 10

Caries
Fractured teeth
Periapical root abscess
Secondary sinusitis
step/wave mouth
hooks/ramps
Diastema- abnormal space between teeth
Note food accumulation
Routine development of enamel points
Mucosal ulcers
Ectopic teeth- Dentigerous cyst
Supernumerary
Very old: worn out/expired teeth

Question 11

Treatment of equine dental disease

Answer 11

Carious lesions can be filled
Extraction
Sinusotomy

Question 12

Prevention of equine dental disease

Answer 12

Regular oral exam
Corrective teeth floating

Question 13

Esophageal obstruction in horses is and can be caused by

Answer 13

Also called choke
Food obstructs esophagus- NOT the airway but is still a potential emergency.
Common causes
Dry beet pulp, hay cubes, alfalfa pellets
Poor dentition
“Bolters”
Treats too large e.g. carrots, apples

Question 14

Signs of choke in horses

Answer 14

Extending neck
Pacing, leaving feed
Repeated swallowing
Retching
White or green frothy nasal discharge
!!!Advise client to remove all feed, water and bedding until the vet arrives!!!!

Question 15

treatment of choke in horses

Answer 15

may spontaneously correct
Medication to relax esophagus
Pass nasogastric tube
Systemic antibiotics to prevent pneumonia

Question 16

Prevention of choke in horses

Answer 16

Regular dental care
Soak hard feed
Discourage bolting
“Feed puzzles”
Feed through muzzles

Question 17

Prognosis of choke in horses

Answer 17

Good if the esophagus has no damage and no material was inhaled

Question 18

EGUS is and contributing facotrs

Answer 18

equine gastric ulcer syndrome
ESGD (Equine Squamous Gastric Disease)
EGGD (Equine Glandular Gastric Disease)
Very common: most horses have mild ulceration that forms and heals continuously
Contributing factors:
Horses secrete gastric acid continuously
Infrequent meals
Fasting
High concentrate diets
Stress
High speed exercise
Very course stalky feed (EGGD)

Question 19

Clinical signs of EGUS in horses

Answer 19

Mild colic episodes
Off feed but more commonly WATER
Weight loss if chronic
Reduced performance
Bruxism (grinding teeth)- especially foals
Gastropexy- fast at least 6 hours prior

Question 20

Treatment and prevention of EGUS

Answer 20

Treatment
-Gastroprotectants- e.g. omeprazole (Gastrogard) ranitidine etc.
Prevention
-Alfalfa hay (Ca++ buffer)
-Constant grazing/frequent meals
-Preventative dose gastroprotectants
-Avoid exercise on an empty stomach
-Antacids prior to exercise
Px- excellent

Question 21

Colitis is an emergency because

Answer 21

Severe diarrhea is always an emergency!!!
Endotoxemia
Electrolyte loss

Question 22

Clinical signs of colitis in equine

Answer 22

Colic
Watery diarrhea
Depression
Anorexia
Secondary laminitis

Question 23

Etiology of colitis in horses

Answer 23

Salmonella
Clostridial
Neorickettsia aka Potomac Horse Fever (PHF)
NSAIDs
Antibiotics

Question 24

Treatment of colitis for equine

Answer 24

Hospitalization in isolation
IV fluids, ice boots, supportive care

Question 25

Prevention of colitis in equine

Answer 25

Avoid oral antibiotics
PHF: avoid wetlands with snails +vaccination available (questionable efficacy)
Usually unavoidable

Question 26

Colic causes in equine

Answer 26

Colic = abdominal pain
Causes
Gastrointestinal- gas, impaction, obstruction (displacement, torsion)
Urinary- stones
Liver- inflammation
Reproductive tract: labour

Question 27

Associated risk factors of colic in horses

Answer 27

Dehydration coarse feed sudden decrease in exercise
Feeding meals high in Non structural carbohydrates (NSC)
Normal anatomy- common sites of impaction: cecum, pelvic flexure, transition between large- small colon
Horses can’t vomit/erucate

Question 28

What diseases can mimic colic in horses

Answer 28

Pleuropneumonia
Laminitis
Fracture

Question 29

Mid signs of colic in horses

Answer 29

Reluctance to move
Flank watching
Lying down
Pawing
Teeth grinding

Question 30

Severe signs of colic in horses

Answer 30

Kicking
Stretching
Roling
Refusal to stand
Sweating
Depressed

Question 31

Instructions to give owners when they cal about the horses with colic

Answer 31

Avoid giving meds
Don’t want to mask symptoms with analgesics
Avoid oral drenching especially with mineral oil
With hold food but not water
Prevent horse from excessive rolling/hurting itself
If resting quietly horse can lie down
Walkin in an environment free from hazards
Stay safe themselves
An otherwise very well-trained horse may suddenly go down on top of you

Question 32

How to tell if colic is small intestinal in horses

Answer 32

More severe rapidly progressive clinical signs
Reflux, endotoxemia
Usually surgical
Rapid referral
Px– poor to good with prompt treatment

Question 33

How to tell if colic is in large intestine of horses

Answer 33

Mild, slowly progressive clinical signs
May continue to eat
Usually medical
Px – good to excellent with appropriate treatment

Question 34

Causes of colic in horses

Answer 34

Gas
Motility issue: spasmodic vs ileus
Displacement, entrapment- E.g. Left dorsal displacement, nephrosplenic entrapment (LI), epiploic foramen entrapment (SI)
Volvulus/torsion- e.g. mesenteric volvulus
Strangulation- e.g. strangulating lipoma
Obstruction
- E.g. trichophytobezoars (hairballs), parasites
Impaction – poor quality feed+dehydration, sand
Infection- E.g.salmonella

Question 35

Treatment of colic in horse

Answer 35

Medical vs surgical
Making the decision to go to surgery quickly is key to success
Looking in the abdomen may be diagnostic as well as provide treatment
**Warn owners not all conditions can be treated even with surgery: not all the gut is visible or accessible even when the abdomen is open
Any situation which compromises blood supply to intestine results in rapid devitalization/death of intestine and the potential for rupture, endotoxemia etc

Question 36

The colic workup for horses should include

Answer 36

Hx and PE
Diet, water access, deworming schedule
HR: 50-80 bpm moderate pain vs >100
Gut sounds- listen in all 4 quadrants
Blood gas
Electrolytes, systemic lactate
PCV, total protein
Dehydration
Sedation/Analgesics
Rectal exam
Palpable abnormalities?
Nasogastric intubation
Check for reflux
Tx. oral fluids/meds (DSS, mineral oil)
Jugular IV cath
Sometimes in both jugs
Abdominocentesis
Strangulating vs obstructive
Lactae, Culture and sensitivity
IV fluids
Hypertonic
Isotonic (LRS)

Question 37

Abdominocentesis is done by

Answer 37

Shave and sterile prep a 10cm square at the most ventral point of abdomen at midline or a little to right of midline (to avoid hitting spleen which sits to left of midline)
Or ventral midline more cranially where pectorals form a “V” caudal to sternum
+/- local anesthetic bleb and scalpel cut down to abdominal wall
18g ½” needle or teat canula
Let the blood drip into a purple top tube

Question 38

Colic fluids should be given to horses because

Answer 38

Rapid onset massive systemic dehydration
Sequestered fluid in intestine
Acidosis
Compromised bowel
Goals
Replace volume
deficit+maintenance(~50ml/kg/day)+ongoing losses
Support systemic blood pressure

Question 39

How would you administer colic fluids in horses and why

Answer 39

Intravenous
-Dehydration >5%
-Suspected obstruction
-Signs of shock
Oral
-Dehydration <5%
-Functional GIT
-No signs of shock

Question 40

What type of fluids would you give to a colicy horse

Answer 40

7.2% hypertonic saline
Rapidly restores systemic volume by drawing interstitial reserve into the vessels by hyperosmotic draw
Greater than 5% dehydrated or systemic lactate greater than 4 mmol/L
1 L hypertonic saline = 10 L of normotonic fluids
MUST BE FOLLOWED BY AT LEAST 10 L OF NORMOTONIC FLUIDS!
Intravenous-Lactated Ringers Solution (LRS)
Most horses with colic are acidotic from dehydration and/or compromised bowel
LRS is metabolized by the liver to produce a buffer to increase the systemic lactate
Oral – Balanced electrolyte solution
Horses with no obstructions
Ideal for large colon impaction

Question 41

What rate of fluid would you give a colicy horse

Answer 41

Intravenous
Shock bolus = 20 mL per kg over 30-60 minutes
Reassess
2 times maintenance until remainder is replaced
Maintenance = 2 mL per kg per hour
Oral
Bolus
20 mL per kg per hour
But never sure if the stomach is entirely empty, so bolus 8 L every one to two hours to be safe
CRI
8–20 mL per kg per hour (4–10 L per hour)
Most horses tolerate 4 L/ hr very well