Equine Muscle Exam

Question 1

Skeletal muscle composition in horses

Answer 1

> 50% of body weight is MM
@vo2 max 78% of TCO

Question 2

Methods for diagnosing muscle disease

Answer 2

History
PE
Chemistry - myoglobin
Imaging
GT
Biopsy

Question 3

Indications in PE

Answer 3

Lack of symmetry
Cardinal signs of inflammation
Observe signs of lameness

Question 4

Diagnostic tools for MD

Answer 4

Ultrasound
Thermography
Scintigraphy
Radiography
Biopsy
Genetic testing

Question 5

Theory of exercise respond test

Answer 5

Comparing CK at rest and post exercise
CK should only be slightly elevated in NA
With muscle disease present CK will be extremely elevated

Question 6

features of Exertional rhabdomyolysis

Answer 6

Tying/lack of use
Monday morning / rest after work
Azoturia
Sporadic, chronic, recurrent, PSSM, enzyme deficiency, mitochondrial, inflammatory, seasonal myopathy

Question 7

Pathogenesis of PSSM

Answer 7

Subset to chronic ER
Type I - genetic mutation, glycogen accumulates inside muscle cell, formation of abnormal poly
Type II - idiopathic, biopsy shows clumping of glycogen

Question 8

PSSM type I

Answer 8

Metabolic abnormality
QH, draft, warm bloods
Clin sign : muscle stiffness, intolerance, reluctance, atrophy renal failure - colic like symptoms

Question 9

Appearance of PSSM muscle biopsy

Answer 9

Subsarcolemmal vacuoles
Period acid Schiff
Lacking AMS digestion

Question 10

Treating acute PSSM

Answer 10

Rest, fluid therapy, NSAID
Daily exercise & slow periods

Question 11

Prevention of PSSM diet

Answer 11

Low carbs, rationed diet, supplement Vit E and selenium, electrolyte complex

Question 12

Features of post anesthetic myopathy

Answer 12

Unilateral in triceps
Bilateral - glutes / Longissimus
Immediate or delayed
Treat as acute ER

Question 13

Features of Hyperkalemic periodic paralysis

Answer 13

Genetic in QH
Na channels leak, membrane is hyperexcitable
Similar to seizures, unresponsive, death can occur
Triggers - high K diet, quick diet changes, stress, fasting, anesthesia

Question 14

Treating HYPP

Answer 14

IV calcium gluconate - reset membrane potential
5% dextrose - promotes K reuptake by cells
Tracheostomy - restore airway
Stimulate insulin
Epinephrine
Acetazolamide

Question 15

Prevention of HYPP

Answer 15

Decrease dietary K
Alfalfa, brome, canola oil, soy bean meal, molasses, kelp
Regulate feeding to regulate channels + insulin
Avoid cold + stress