Day 8 - METABOLIC, ENDOCRINE AND MUSCULOSKELETAL DISEASES IN HORSES

Question 1

Most common electrolyte imbalances (4)

Answer 1

• NaCl deficiency/overdose (foals on milk replacer)
• Late pregnancy tetany (Ca and Mg imbalance) in ponies
• Hypocalcemia
• Hyperkalaemic periodic paralysis (HYPP)

Question 2

Hypocalcemia - Tx

Answer 2

Rapid IV tetracycline (20 ml)

Question 3

Hyperkalaemic periodic paralysis - Dx and Tx

Answer 3

Autosomal dominant trait

Dx: Potassium conc, Genetic tests
Tx: Systemic Acetazolamide, Dextrose, Sodium bicarbonate, Ca gluconate, insulin

Question 4

Vitamin E and Selenium deficiency - diseases (4)

Answer 4

• Equine degenerative myeloencephalopathy (EDM)
• Equine motor neuron disease (EMND)
• White muscle disease
• Yellow fat disease

Question 5

Equine degenerative myeloencephalopathy

Answer 5

Young, ataxia
Give selenium

Question 6

Equine motor neuron disease

Answer 6

Middle/old age.
Dx: Muscle biopsy (sacrococcygeal)
Give selenium

Question 7

White muscle disease

Answer 7

Muscle dystrophy due to low Vit E, Se, Lipid peroxidation (Free radicals)

Lab: Myoglomulinuria, CK (++)
Tx: Vit E + selenium suppl

Question 8

Yellow fat disease

Answer 8

Shetland pony

Vit E, Se suppl.

Question 9

Exertional rhabdomyolysis - two types

Answer 9

Sporadic (acute): Monday morning disease, overexertion

Recurrent:
- Recurrent exertional rhabdomyelyosis
- Polysaccharide storage myopathy
- Equine polysaccharide storage myopathy

Question 10

Exertional rhabdomyolysis - Overexertion

Answer 10

Over performance and poor food.
Glycogen and electrolyte depletion, lactic acidosis

Tx: Rest, flunixin melgumine, infusions

Question 11

Exertional rhabdomyolysis - Monday morning disease

Answer 11

Acute, heavy working draft horses, myoglobulinuria

Question 12

Exertional rhabdomyolysis - recurrent exertional rhabdomyolisis

Answer 12

Event horses, intense exercise, Overfeeding of concentrates with increase carbohydrates,

malignant hyperthermia

Question 13

Exertional rhabdomyolysis - polysaccharide storage myopathy and equine polysaccharide storage myopathy

Answer 13

Genetic,
Due to accumulation of abnormal polysaccharide (amylase resistant or not) within the myoplasm due to glucose metabolism

Dx: Genetic testing, Muscle biopsy

Question 14

Exertional rhabdomyolysis - Tx

Answer 14

o Analgesics (detomidine), sedatives, NSAIDs: flunixin meglumine
o Fluid therapy iv (mannitol) and furosemide: lactated – ringer and NaHCO3 infusion
o Rest, suspension device (ONLY walking)
o B1 + C vitamin, insulin
o Vit E. + selenium

Question 15

Laminitis - Tx

Answer 15

o Sand or deep bedding, stall restriction
o Cryotherapy: PROVEN treatment in acute stage
o Light cast in subacute – chronic cases (> 4 – 5 days)
o DDFT tenotomy
o Corrective trimming, shoeing
o Anecdotal treatments
Isoxuprine – hydrochloride
Acepromazine, heparin, aspirin, DMSO, pentoxyfiline
o Whole frog/solar surface must be EQUAL

Question 16

Cushing’s disease/pituitary pars intermedia dysfunction (PPID)

Answer 16

> 15 yr. Benign adenoma of the pars intermedia.
- Diagnosis
o Baseline ACTH dexamethasone suppression test
o TRH stimulation test

• Treatment
  o Pergolide
  o Imprints (in case of laminitis)

Question 17

Equine metabolic syndrome – type 2 diabetes

Answer 17

Obesity, insulin resistance, chronic, active laminitis.

Dx: Insuline level, Glucose/insulin tolerance test

Tx: Diet, shoeing, grazing muzzle, Metmorfin

Question 18

Hyperlipemia in ponies, donkeys - Dx

Answer 18

Dx:
o Lipaemic plasma
o TG > 5.6 mmol/L (>500 mg/dL)
o Total lipid: 10 – 90g/L
§ Normal: 10g/L
o Severe organ dysfunction
o Lipid embolism can occur due to lipid in circulation
o Can tell macroscopically: yellow and thick blood samples
o 1% is fat of total lipid content

Question 19

Hyperlipemia in ponies, donkeys - Tx

Answer 19

o Elimination of the cause
o Bran + molasses in mild cases to support gut motility
o IV fluid therapy (NB): LRS solution, dextrose, B vitamins
o protamine – Zn insulin SC q12/24 hours
o heparin SC q8 hours
o Parenteral nutrition