A healthy horse's stomach pH should ideally be maintained between 4 and 7 to support good bacteria and protect the lining. While gastric acid ($pH$ 1.5–2) is necessary for digestion and killing pathogens, consistent access to forage (roughage) is crucial to provide a buffering effect, preventing excessive acidity that causes ulcers. [1, 2, 3] 

 

Key Aspects of Equine Digestive pH: 

  • Stomach Acid (1.5–2.5): Natural, high acidity is necessary for digestion. 
  • Buffering (4.0+): Constant eating of fiber creates saliva that raises the pH to safer levels (4-7). 
  • Hindgut Bacteria (6.5–7.0): The large intestine and cecum need a neutral pH, around 6.5–7.0, for healthy fiber-fermenting microbes to thrive. 
  • Acidosis Risk: If the stomach is too acidic ($pH$ $\le$ 4), it can lead to gastric ulcers. If too much starch/sugar hits the hindgut, the pH drops, causing lactic acid buildup and killing good bacteria. [1, 3, 4, 5, 6, 7, 8] 

How to Maintain Optimal pH: 

  • Free-choice foraging: Provide continuous access to hay or pasture to keep the stomach full and buffered. 
  • Fiber-first diet: Reduce grains and high-starch feeds. 
  • Slow feeding: Use slow-feed hay nets to encourage constant grazing. [4, 6, 9, 10, 11] 

Further Exploration 

  • Read about how Kentucky Equine Research explains the chemistry of the equine stomach. 
  • Understand the causes of hindgut acidosis and its impacts from Hygain. 
  • Find out how to manage gastric ulcers with insights from The Horse. [4, 5, 6, 12, 13] 

If you can tell me a bit more about: 

  • The horse's current diet (grain/forage ratio)? 
  • Whether you have concerns about ulcers or behavior? 
  • If you can monitor their manure? 

I can provide more tailored advice. 

 

AI responses may include mistakes.

[1] https://bluebonnetfeeds.com/blogs/default-blog/blog-why-stomach-buffers

[2] https://madbarn.com/horse-digestive-anatomy/

[3] https://www.facebook.com/calmhealthyhorses/posts/it-pays-not-to-mess-with-gastric-aciditynowadays-horse-owners-place-a-big-emphas/5247688158611227/

[4] https://ker.com/equinews/barnyard-chemistry-ph-and-equine-digestive-tract/

[5] https://beva.onlinelibrary.wiley.com/doi/10.1111/eve.12505

[6] https://hygainfeeds.com/the-411-on-hindgut-acidosis-in-horses/

[7] https://www.equine74.com/blog/gastric-acid-in-horses

[8] https://formahoof.com/hindgut-microbes-and-hoof-health

[9] https://askheltie.com/en/articles/heltiehorse/how-do-you-keep-the-ph-value-of-the-horses-stomach-balanced

[10] https://www.pferdeklinik.ch/en/medical-conditions/stomach-ulcer/

[11] https://www.succeed-equine.com/expertise/blog/horse-health/the-owners-guide-to-the-microbiota-in-horse-health-disease/

[12] https://thehorse.com/1107763/how-diet-affects-equine-gut-health/

[13] https://www.redmillshorse.com/en-ae/nutritional-hub/nutritional-articles/feed-horse-gastric-ulcers/