04/09/2026
Clarifying the Calm Healthy Horses Message
The Integral Equine post and PDF, “Grass affected — real or pseudo-science?”, misrepresents our CHH message.
In fact if the author of the article really understood our information, what we do and how much support we give people 24/7 the tone of the FB Post/article would be quite different.
CHH coined the term “grass-affected” as a practical, descriptive term to draw attention to grass and how it can adversely affect the metabolism of many domestic horses. The purpose being to help owners identify the cause of their horse’s health, movement and/or behaviour issues, often when all else has failed. It is not a veterinary diagnosis.
We draw attention to various aspects of pasture, particularly those inherent in cool season grasses when they are the predominant forage ALL YEAR ROUND.
Same for warm season grasses under certain conditions, they also create a different set of issues for horses grazing them.
We explain the cyclical/seasonal nature of the horses ‘natural’ diet where they do consume green grass in the spring but for most of the year their forage is more mature and their metabolism has an annual rest over the long, harsh winters.
The relevant question is whether the horse’s current pasture, total intake and management suit that individual horse.
‘Grass-Affected” does not mean all grass is harmful.
Over the last 20 years, we have seen significant improvements in our own horses and received countless reports from clients whose horses improved in comfort, behaviour, movement and digestive function after making the forage and management changes that better suit the equine digestive system and overall metabolism.
The article suggests that, “in most cases”, grass-affected issues can be explained by a sudden dietary change. This may explain some cases, but no evidence is provided to establish that it explains most.
Our work primarily involves horses with persistent or recurring problems - not simply horses reacting briefly from spring grass growth.
Potassium: We agree that Potassium is essential and that horses commonly consume more than their minimum requirement from forage.
However, chronically high potassium intake can result in disturbances to blood calcium levels****. It also elicits an insulin response**
Hemolysis of blood samples is always reported on blood test reports so a person knows to disregard high potassium readings in these cases.
The article also states that nitrates are not “normal” in grasses.
Nitrate occurs naturally in plants especially in cool season grasses. Under certain environmental/growing conditions they can rapidly accumulate.
How well any individual horse copes in these situations depends on his metabolic status at the time.
Horses have zero requirement for nitrates and differ from ruminants in their response.
Nitrates are converted into urea in the liver ready for excretion via the kidneys – they cause horses to urinate more often and can cause their urine to smell of ammonia. They are a known cause of digestive and many other issues.
Incorporating these factors into a complete dietary assessment from which management and dietary adjustments are made, considerably improves the horses’ comfort, movement and behaviour.
CHH would have welcomed direct questions before this inaccurate characterisation of our approach was published.
Video – lowering potassium intake can make a significant difference to neurological issues such as head-shaking as in the case of Hoover in the video.
References
*Merck Veterinary Manual: Nitrate and Nitrite Poisoning in Animals
**Mineral Tolerance of Animals (2005) Ch 24- Potassium, Ch 34 Nitrates
*** Christine Janis, The Evolutionary Strategy of the Equidae and the Origins of Rumen and Cecal Digestion
**** Equine Nutrition and Feeding – David Frape