III - Skeletal Muscle Disease

Question 1

What is the clinical use of serum chemistry in the diagnosis and treatment of equine muscle disease?

Answer 1

Look at CK and AST.

CK
- released into circulation with myofiber damage
- rapid peak and decay
- normal <300 IU/L

Question 2

List causes of focal muscle atrophy.

Answer 2

Denervation
Osteoarthritis
Trauma
Neoplasia
Immune mediated

Up to 2/3 of muscle mass may be lost within 2-3 weeks of peripheral denervation. Easier to assess than generalized unless it’s bilateral.

Question 3

List causes of muscle hypertrophy.

Answer 3

Training
Compensation for fiber loss elsewhere
Muscle disorders

Question 4

Name the anatomical sites commonly used to obtain a muscle biopsy.

Question 5

DFDX for a horse with a mild (<1000 IU/L) increase in serum CK activity.

Question 6

What are the most common clinical signs of rhabdomyolysis?

Question 7

How would you diagnose rhabdomyolysis?

Question 8

How do you treat rhabdomyolysis?

Question 9

Explain to an owner the precautions you will take to prevent anesthesia-related rhabdomyolysis.

Question 10

Explain the pathophysiologic basis underlying the most common acid-base disturbance in exhausted horses.

Question 11

List genetic causes of rhabdomyolysis in different horse breeds.

Question 12

Compare genetic causes of rhabdomyolysis in terms of inheritance.

Question 13

Compare genetic causes of rhabdomyolysis in terms of pathophysiology.

Question 14

Compare genetic causes of rhabdomyolysis in terms of clinical signs.

Question 15

Compare genetic causes of rhabdomyolysis in terms of diagnosis.

Question 16

Compare genetic causes of rhabdomyolysis in terms of treatment.

Question 17

Compare genetic causes of rhabdomyolysis in terms of prevention.

Question 18

What is known about shivers?

Question 19

What breeds does shivers affect?

Question 20

Explain the mode of inheritance for HYPP in Quarter horses.

Question 21

Name the specific stallion associated with HYPP.

Answer 21

Impressive

Question 22

Explain the cause of white muscle disease.

Question 23

Describe the clinical signs of white muscle disease.

Question 24

Describe how to diagnose white muscle disease.

Question 25

Describe how to treat white muscle disease.

Question 26

What is the classic presentation and case history of a horse with clostridia myonecrosis?

Question 27

Provide a diagnostic plan for a horse with clostridial myonecrosis.

Question 28

Provide a treatment plan for a horse with clostridial myonecrosis.

Question 29

List causes of generalized muscle atrophy.

Answer 29

Equine Motor Neuron disease
Vitamin E deficiency
Immune mediated myosin is
PSSM1 homozygotes

Harder to identify subtle changes without routine monitoring of muscle mass.