Veterinarians at Rood and Riddle Equine Hospital answer your questions about sales and healthcare of Thoroughbred auction yearlings, weanlings, 2-year-olds and breeding stock. Email us at [email protected] if you have a question for a veterinarian.
Question: I’ve heard that baking soda can help a number of medical conditions for horses, including gastric ulcers. Is its versatility more miracle or myth?
Dr. Peter Morresey, Rood and Riddle Equine Hospital: Sodium bicarbonate (baking soda) has myriad uses around the home: cooking, cleaning, and freshening the air. It is a kitchen staple. There is also a lot of information available anecdotally and on the internet as to the supposed benefits of its use in horses, whether strategically for performance enhancement or every day for overall health improvement.
Bicarbonate has a degree of notoriety due to the act of ‘milkshaking’ – giving horses a large quantity prior to strenuous exercise to allow them to combat fatigue towards the end of a race.
There is a reason this is illegal – performance-enhancing effects have variably occurred in controlled studies.1-3 Also, bicarbonate administration, if sufficient, can alter urine pH and drug elimination potentially allowing ‘doping’ with banned substances.4
To maintain the integrity of and public confidence in equine sporting activities, testing of blood pH (acidity) via total carbon dioxide levels (TCO2) is regularly performed to ensure this remains within the expected range for healthy horses. Deviations are taken as proof of the administration of bicarbonate and significant penalties follow. Very few horses would naturally achieve these pH levels, although any supplementation in the diet should naturally be done with care. Large amounts must be administered to meaningfully change the acid-base status of the horse to combat fatigue, and nasogastric administration is necessary. Up to one pound may be necessary.5
It’s not really that easy to use bicarbonate to improve the health of horses in everyday life. Prevention of muscle enzyme increase post exercise leading to ‘tying-up’ has not been proven experimentally.6 Addition to water in amounts in common usage does not increase intake.1 Bicarbonate simply does not taste good. Horses will not voluntarily consume the amount required to change anything, no matter how you disguise it. That is a distinct disadvantage when it has a medical indication. A condition known as renal tubular acidosis which causes unsafe blood pH through alterations in bicarbonate levels, while rare, is a significant problem for those horses who suffer from it. The amount of bicarbonate needed to counter its life-threatening effects and enable a normal life are very hard to add to feed and have voluntarily accepted.
Bicarbonate dissociates in water. It is also immediately broken down by the acidity of the stomach to produce carbon dioxide, making it unavailable to the lower gut (where it supposedly reaches allowing its beneficial actions). This gas does not linger in the stomach as gas causing bloating, rather it is absorbed into the blood and alters total carbon dioxide, a measure of blood pH. It simply does not have the direct effects commonly ascribed to it.
All of that does not mean bicarbonate could not have beneficial effects. High grain diets promote acidity during digestion. This happens in areas of the gut that a horse eating forage only would not experience. These acids are irritant and can draw water into the gut. Bicarbonate, if it can reach the intestinal tract, would be of great benefit to counter this acidity. Protected bicarbonate can pass the stomach and reach to lower gut for buffering of content and absorption. This is achieved by coating the bicarbonate with oil or fat which resists gastric acid destruction of the bicarbonate. These products are commercially available and find usage in the management of digestive upsets and lower gut gas production.
There will be no harm adding a small amount of bicarbonate (regularly 1-2 tablespoons) to your horse’s feed. It just may not do the good you have been told it will. If amounts sufficient to enable a therapeutic effect are needed for the health of your horse, your veterinarian can recommend methods to do this that the horse will accept.
1. Schott II HC and Hinchcliff KW. Treatments affecting fluid and electrolyte status during exercise. Veterinary Clinics of North America: Equine Practice 1998;14:175-204.
2. Popplewell JC, Topliff DR, Freeman DW et al. Effects of dietary cation-anion balance on acid base balance and blood parameters in anaerobically exercised horses. Journal of Equine Veterinary Science 1993;13:552-555.
3. Schuback K, EssenGÇÉGustavsson B, Persson SGB. Effect of sodium bicarbonate administration on metabolic responses to maximal exercise. Equine Veterinary Journal 2002;34:539-544.
4. Lloyd DR, Rose RJ, Duffield AM et al. Effects of sodium bicarbonate and sodium chloride on the elimination of etorphine in equine urine. Journal of analytical toxicology 1996;20:81-88.
5. Lloyd DR and Rose RJ. Effects of sodium bicarbonate on acid-base status and exercise capacity. Equine Veterinary Journal 1995;27:323-325.
6. McKenzie EC, Valberg SJ, Godden SM et al. Effect of dietary starch, fat, and bicarbonate content on exercise responses and serum creatine kinase activity in equine recurrent exertional rhabdomyolysis. Journal of Veterinary Internal Medicine 2003;17:693-701.
Dr. Peter Morresey began his career in New Zealand as a mixed animal practitioner following graduation from Massey University in 1988. He completed a theriogenology residence at the University of Florida and spent time as part of the clinical faculty at the University of Pennsylvania. Areas of interest include reproduction, internal medicine, neonatal medicine, veterinary business and Chinese medicine.