I love seminar notes. Rarely can I take the time to go back and watch an entire presentation, but I do re-read my scribbles for a refresher on the key points. I hope that sharing them here will be helpful to you as well.
Of course, I can’t possibly share all the details from this stellar session by Langdon Fielding, DVM, MBA, DAVECC, DACVSMR, and self-proclaimed electrolyte fanatic. To really take advantage of his generosity, register with AERC to access the 2021 Unconventional Convention content, which will be available through the end of March 2021.
Sodium in Endurance Horses
Dr. Fielding began by sharing a typical lab panel taken from an “Ain’t Doin’ Right” horse at an endurance ride. The panel showed higher than normal sodium and lower than normal potassium, chloride, and calcium. He posed the question: Is the problem here too much sodium or too little water?
Because sodium is all about the balance between electrolytes and water, identifying which side of the equation (sodium or water) got the level out of whack is key to preventing a repeat performance.
Potassium in the Endurance Horse
Moving on to potassium, Dr. Fielding said so much of this electrolyte is lost in sweat that low levels are common on lab panels taken during endurance events. Some horses tolerate low potassium better than others, and it’s not always problematic. However, low potassium is common in horses that are struggling or require treatment.
Dr. Fielding added that although weakness is a classic symptom of low potassium, this can be hard to differentiate from normal fatigue in an endurance horse.
Calcium and Thumps in the Endurance Horse
Dr. Fielding noted that although calcium is clearly tied to muscle and heart function, it is less consistently associated with endurance horses that are having trouble.
Low calcium, typically in addition to loss of potassium, chloride, and sodium (in Dr. Fielding’s words, "lots of electrolyte abnormalities colliding"), can contribute to synchronous diaphragmatic flutter, or thumps. Interestingly, thumps may be observed in a horse that is otherwise fine, as well as in a horse that is exhausted.
Dr. Fielding noted that feeing a horse alfalfa (which is high in calcium) can help thumps resolve within an hour or two, but cautioned that giving electrolytes to the horse could be risky if the horse is dehydrated. He said a vet would generally treat thumps with IV fluids including calcium.
It is possible – though this has not been rigorously tested – that feeding a low calcium diet during conditioning, then offering alfalfa just before the ride, can help prevent thumps. Dr. Fielding cautioned against doing the reverse; that is, eliminating alfalfa at a ride if a horse is accustomed to consuming it.
Dr. Fielding wrapped up his presentation with a reminder that problems in endurance horses aren't always about electrolytes…and when they are, the answer isn’t always about changing products or administering more.
Did you get a chance to listen to Dr. Fielding's talk? What did you find most interesting?
You might also like: Dr. Stephanie Seheult on How Your Body Works with your Horse
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Thanks for dropping by! I'm an endurance rider in the northwest region of the United States. This blog is about distance riding, training, and the practice of being my best self for my horse. I hope you'll come along for the ride.