Equine Gastric Ulcers / A Presentation by Wendy Harless Mollat, DVM, DACVIM, Pilchuck Veterinary...

7/29/2019 Equine Gastric Ulcers / A Presentation by Wendy Harless Mollat, DVM, DACVIM, Pilchuck Veterinary Hospital

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Wendy Harless Mollat, DVM, DACVIM

Board Certified Large Animal Internal [email protected]


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Equine Gastric Ulcer Syndrome

Equine Stomach Anatomy and Physiology

Clinical Signs

How Ulcers Form

Key Risk Factors

Diagnosing and Classifying Ulcers

Treatment Options

Prevention

Questions?


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Equine Gastric Ulcer Syndrome

Very similar to Gastric Esophageal Reflux

Disease in humans

Very prevalent in performance horses of any

discipline


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Prevalence and Impact

At least 90% of race horses

At least 60% of performance horses

Most all competitive horses will suffer from an

ulcer sometime in their competitive career

25 57% of foals have ulcers

These are potentially fatal if clinical illness is

present

Significantly affects condition and performance

Murray et al, Equine Vet J, 1989 &1996; Murray, JAVMA, 1989; Murray,AAEP, 1997.


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Gastric Ulcers in Foals

Foals Ulcers develop very quickly in foals and can be

fatal

Clinical Signs: Poor appetite or intermittent nursing

Colic

Poor body condition

Frequently lies on back

Teeth grinding (bruxism)

Excessive salivation (ptyalism)

Diarrhea

Murray, Vet Med, 1991.


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Stomach Anatomy

Healthy Stomach Ulcerated Stomach


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Stomach Anatomy

Esophagus:Squamous lining

Duodenum:outflow to small

intestine

SquamousMucosa:80% of ulcers

occur here;

highly

susceptible toinjury

Glandular Mucosa: well protected

from damage; 20% of ulcers occur here

Margo

Plicatus:

area of fluidline in

stomach;

ulcers usually

start in this

region


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Basic Stomach Physiology

Acid Secretion in the horse:

Occurs 24 hours a day/ 7 days a week

Adult horses produce up to 4 gallons/day

Even foals as young as 2 days of age have high levels ofacid detected in stomach

Other factors that contribute to ulcers:

Hydrochloric Acid

Pepsin Weak Organic Acids

Bile Salts


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How Ulcers Form

Protective

Mechanisms

Erosive

Mechanisms


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Protective Mechanisms

Salivary flow

Grass or continuous hay

Cell turnover within

stomach Mucosal blood flow

Mucus/Bicarbonate barrier


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Erosive Mechanisms

Gastric acid (hydrochloric acid) always there!

Feed deprivation

Pepsin

Reduced blood flow to stomach lining

Intense exercise

High grain diets


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Risk Factors

Eating and Feeding Patterns

Exercise

Transportation

Stress


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Eating and Feeding Patterns

Episodic feeding: feeding1X, 2X or 3X/ day

Withdrawal of feed prior

to work Diet selection: Grain &

concentrate vs. hay/grass

Change in feeding routine,

particular when traveling


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Feed Deprivation Model

48 hours0 hours 96 hours

Murray and Schusser, Equine Vet J, 1993; Murray and Eichorn,Am J Vet Res, 1996.


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Hours

0

1

2

3

4

5

6

7

pH

0 6 12 18 24

GOOD

Bad

Murray and Schusser, Equine Vet J, 1993

24 hour Gastric pHNo Feed


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24 hour Gastric pH Free Choice Grass Hay

Hours

0

1

2

3

45

6

7

8

pH

0 6 12 18 24

Good

Bad

Murray and Schusser, Equine Vet J, 1993


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Feed Types

Forage

vs.

Concentrates

(grain)


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Exercise


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Gastric Volume with Exercise


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Stress

Physical Training/competition Illness Painful disorders

Surgery Lameness

Behavioral Stall confinement Transport Unfamiliar environment Social regrouping


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Stress & Transportation

Gastric ulcer development in horses in a

simulated show or training environment

5 Day Study:


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Study Protocol

McClure, et al, JAVMA, Vol 227, No. 5, Sept 1,2005; pp 775-777

20 ulcer-freeAPHA horses

10 trailered4 hours10 kept at

home

Fed oats +grass/alfalfa

Trailered back

4 days later

Mild exercise30 min 2x daily

Scopedbefore &

after


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Outcome of Study

McClure, et al, JAVMA, Vol 227, No. 5, Sept 1,2005; pp 775-777

10 traileredhorses

10 kept at

home

Scopedat end

of 5-daystudy2 with

ulcers7 withulcers


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Photos courtesy of MJ Murray

Healthy stomach Ulcerated stomach

5

days

Results


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Clinical Signs

How would a horse owner recognize ulcers? Weight loss

Change in attitude/behavior or work ethic

Intermittent colic

Dull coat

Poor doer

Change in eating patterns

Horses react to pain in a variety of ways

Reluctance to perform

Stiffness Lack of response to leg

Holding their body in this case leading to back pain


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Diagnosis

Clinical Signs

Suggestive but not specific

Response to treatment

Definitive Diagnosis =

Gastroscopy

Requires a 3 meter scope

Patient preparation

Experience

Murray, Vet Med, 1991.


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Gastroscopy


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Classifying Squamous Ulcers

Grade 0 = normal stomach


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Grade1 = hyperkeratosis


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Grade 2 = small single or

multi-focal ulcers


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Grade 3 = large; single ormulti-focal ulcers


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Grade 4 = severe ulcers;often coalescing with deep

areas


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Glandular Ulcers

No current grading scale

Normal Pylorus Pyloric ulcers


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Glandular Ulcers


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Classifying Ulcers

Biggest take away = NO CORRELATIONBETWEEN CLINICAL SIGNS AND

SEVERITY OF ULCERS!


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Current Therapy Options

What are people using to treat gastric ulcers?


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Manage Gastric Acid Antacids

Sucralfate

Histamine H2 Blockers

Omeprazole


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Goal of treatment: Control pH of stomach

Maintain pH above 4.0

At least 22 of every 24 hours

0 4.0 7 pH Scale 14

Acid Neutral Alkaline

(Water)

Lambert,Aliment Pharmacol Ther, 1997


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Treatments act at different sites

Site of ActionH2 antagonists

GASTROGARD

Sucralfate

Antacids H+CI-

H2 (+) ACh (+) Gastrin (+) Prostaglandins (-)

H+ H+CI- CI- H+ CI

- STOMACH

LUMEN

MUCUS/BICARBONATE BARRIER

PARIETAL

CELL

H+

H+

H+

ACID PUMP


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Antacids

Neutralized gastric acid

Aluminum or magnesium

hydroxide

Large volumes (250ml)

Very short term effect


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Sucralfate

Aluminum salt of sucrose

Binds to ulcer crater with

appropriate pH

Good adjunct therapy,

especially for pyloric

ulcers


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Histamine H2 Blockers

Ranitidine*, cimetidine

Prevents histamine from

binding to H2 receptor in

stomach

Reduces stomach acid

Variable absorption

Short acting = three times

per day dosing

O


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Omeprazole

Proton (acid) pumpinhibitor

Must be absorbed in the

small intestine into bloodstream

Very effective, but long

treatment

C Th O i


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Compounded omeprazole products

Two trials:

1st trial looking at active ingredient (omeprazole) in

compounded products Poor results

2nd trial looking at their efficacy

Horses on compounded product or GASTROGARD for

28 days under ulceragenic conditions

Each group switched at the end of 28 days


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UlcerGard vs. GastroGard

GASTROGARD (Rx) Treatment of diagnosed ulcers

(4 mg/kg once a day=full tube)

28 days following treatment for healing process(2mg/kg once a day=1/2 tube)

ULCERGARD (Non-Rx)

For true prevention of ulcers during stressful

events: training, competition, transport, weaning,surgery, stall confinement, etc.

(1 mg/kg once a day=1/4 tube)

I li i


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1. Ulcers can happen fast2. Multiple factors can lead

to development of ulcers

3. Ulcers are not exclusive

to high-performance

horses

Implications

Q ti ?


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Questions?

Thank you!

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Equine Gastric Ulcers / A Presentation by Wendy Harless Mollat, DVM, DACVIM, Pilchuck Veterinary...

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