Changes

Also known as: '''''SDF — Thumps — Exhausted horse syndrome'''''

Also known as: '''''SDF — Thumps — Exhausted Horse syndrome'''''

==Introduction==

==Introduction==

Synchronous diaphragmatic flutter is a condition characterised by '''unilateral or bilateral contraction of the horse's diaphragm'''. It results from electrolyte losses that occur during '''physical exertion''' or from '''hypocalcaemic tetany''' or hypocalcaemia secondary to blister beetle toxicosis.

Synchronous diaphragmatic flutter is a condition characterised by '''unilateral or bilateral contraction of the horse's diaphragm'''. It results from electrolyte losses that occur during '''physical exertion''' or from '''hypocalcaemic tetany''' or [[hypocalcaemia]] secondary to blister beetle toxicosis.

This syndrome is often seen in horses participating in competitive '''trail and endurance races''' or on long-distance rides.

This syndrome is often seen in horses participating in competitive '''trail and endurance races''' or on long-distance rides.

A decrease in the plasma calcium, chloride and/or potassium concentration, or a body deficit of these electrolytes, '''sensitises the phrenic nerve to the depolarising electrical activity of the adjacent myocardium'''. Therefore the involuntary diaphragmatic contraction and "thump" are '''synchronous with the heartbeat''' and not with the breathing cycle.

A decrease in the plasma calcium, chloride and/or potassium concentration, or a body deficit of these electrolytes, '''sensitises the [[Diaphragm - Anatomy & Physiology#Innervation|phrenic nerve]] to the depolarising electrical activity of the adjacent myocardium'''. Therefore the involuntary diaphragmatic contraction and "thump" are '''synchronous with the heartbeat''' and not with the breathing cycle.

This can occur during or following physical exertion, severe diarrhoea or colic, or following prolonged surgery and anaesthesia.

This can occur during or following physical exertion, severe diarrhoea or [[:Category:Colic in Horses|colic]], or following prolonged surgery and anaesthesia.

==Clinical signs==

==Clinical Signs==

Pathognomonic clinical signs include: '''sudden bilateral or unilateral movement of the horse's flanks''' (and sometimes hindlimbs) each time the heart beats. The "thump" can usually be '''heard or palpated over the thorax or flanks'''.

Pathognomonic clinical signs include: '''sudden bilateral or unilateral movement of the horse's flanks''' (and sometimes hindlimbs) each time the heart beats. The "thump" can usually be '''heard or palpated over the thorax or flanks'''.

Typical '''biochemical abnormalities''' include: '''hypoglycaemia''', increased fatty acid concentrations, '''hyponatraemia, hypochloraemia, hypokalaemia, hypocalcaemia, hypomagnesaemia and hyperphosphataemia'''.

Typical '''biochemical abnormalities''' include: '''hypoglycaemia''', increased fatty acid concentrations, '''hyponatraemia, hypochloraemia, hypokalaemia, hypocalcaemia, hypomagnesaemia and hyperphosphataemia'''.

Blood lactate and Creatine Kinase might be moderately elevated.

Blood lactate and creatine kinase might be moderately elevated.

'''Dehydration''' might also be observed.

'''Dehydration''' might also be observed.

Stashak, T. (2002) '''Adams' Lameness in Horses''' ''Wiley-Blackwell''

Stashak, T. (2002) '''Adams' Lameness in Horses''' ''Wiley-Blackwell''

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[[Category:Neurological Diseases - Horse]]

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