Sporadic Exertional Myopathy –
Synchronous Diaphragmatic Flutter (Thumps) "Thumps" is described as the abnormal contraction of the
in sync with
the rhythm of the
.
It is associated with strenuous exercise and excessive sweating leading to
.
Hypocalcemia causes the resting membrane potential of the nerve to become more positive. Depolarization of the atria of the heart causes a local electromagnetic change in the extracellular fluid that pushes the resting membrane potential of the phrenic nerve to reach threshold value. Once threshold value is reached the nerve generates an action potential that is propagated toward the neuromuscular junction with the diaphragm. The diaphragm contracts in response to the nervous stimulation.
Thumps occur more commonly in warm, humid weather and are seen in individuals who are sweating heavily, such as racehorses and horses.
The clinical signs and symptoms of thumps include a rhythmic twitching of the that may resemble a hiccough, a dull thumping sound that occurs with the flank twitch, rapid and laboured breathing, difficulty in recovering breathing after exercise, anxiety, dehydration, heat stress and shock.
Diagnosis of thumps can be made through the clinical signs and symptoms and through blood chemistry.
Treatment is to restore the electrolyte balance by the administration of IV lactated ringer’s solution.
Thumps may be prevented by the inclusion of an electrolyte
in the
diet of performance horses, and by the monitoring of the horse’s hydration levels.
Fibrotic and Ossifying Myopathy Fibrotic and ossifying myopathy is a progressive condition in which muscle tissue is replaced by fibrous scar tissue and adhesions and over time the scar tissue can become ossified.
Fibrotic and ossifying myopathy is caused by repeated muscular strain in the In some individuals the condition is congenital, and the etiology is idiopathic.
.
Abrupt turns and stops cause strain and tearing on the muscles of the hamstrings. The areas of damage are replaced by fibrotic scar tissue, and adhesions are formed in the surrounding muscle and fascia. As fibrotic tissue is less resilient and elastic than muscle tissue the hamstrings are
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