How Grass Affects HorsesNevavda - grass affected!

When wild horses get the opportunity to consume green, growing grass at certain times of the year they too become obese and develop laminitis and other problems seen in our domestic horses on similar tucker. (Hampson & Pollitt)

Originally I thought it was all about which species of grass the pasture consisted of. Whilst this is still true we have since learned that no matter what the species, whether it is horse-friendly grass or not, the nutrient status of that grass, which constantly changes because it is influenced by the soil, fertilisers, the season and the weather, also determines whether the grass is suitable fodder for your horse to consume. It can literally be suitable one day and not suitable the next!
Therefore pasture management suitable for horses is actually the secret to maintaining healthy horses on grass.


The Grass?

How do you know it is the grass that causes these problems?
affectedSimple! When you remove green, growing, over-grazed or otherwise stressed grass from the horse’s diet the vast majority of the problems go away.
Some of the more serious problems like head-flicking take a bit longer and may need a little more help but the differences seen when the ‘bad’ grass is removed is unmistakable.
When you read and understand the information on this website it will be just like someone has given you a new pair of glasses. Light bulbs will go on for you regarding horses you currently own or know of, or have owned or known in the past. You too will realise how countless, perfectly good horses have suffered, been punished, become 'problem horses', caused accidents, been labelled 'bad', 'nuts', 'unmanageable', deemed unrideable, diagnosed with brain tumours, wobbler syndrome, have ended up in court cases and even been sent to the knackers, all because they were forced to graze completely unsuitable grass!

This information provides an explanation for many things going on with our horses where extensive investigations have previously failed. It comes from years of my own personal observations and experiences and those of the hundreds of horses and riders I have met and assisted over the last fifteen years throughout New Zealand and Australia. Additionally, in the spring of 2004, I conducted the Equine Health and Behaviour Survey in New Zealand, the results of which were very revealing.

A lot of this information ‘is not in the text-books’. This is why it has taken so long to figure it all out. Now I realise that the science is always 5-10 years behind the anecdotal evidence. It takes years to conduct trials, write up the results and get your paper reviewed and published.

What are the Symptoms?

Exactly HOW does grass affect horses?

It is a simple matter of the physiology of the grass affecting the physiology of the horse.
In a nutshell grass requires potassium and nitrogen to grow and therefore sucks it up into the plant at every opportunity. This is facilitated by rainfall as it travels up into the plant with water. It is no coincidence that people report that their horses are ‘worse’ after rain. Drought-breaking rains can be lethal to livestock for this very reason.
(See Grass Tetany)

Nevada demonstrates grass affected behaviourAny grass under stress or influenced by certain climatic conditions for example those of early spring and autumn, especially after drought-breaking rains or consecutive cool, cloudy, wet or frosty days, is subject to acute spikes of potassium and nitrate at the same time as being low in sodium.
This is exacerbated by nitrogenous fertilisers

The potassium nitrate ingested is highly toxic and the horse’s body rapidly uses up available chloride, calcium and magnesium to excrete them. Hence the necessity to feed adequate salt (sodium chloride) and calcium/magnesium while not adding to the potassium load with Lucerne/molasses, many herbs/garlic, or high protein feeds and supplements containing potassium.

As all grass always tends to be high in potassium and low in sodium, the metabolism of horses and other herbivores are normally well adapted to handle it. Their bodies, like ours are equipped with various, very efficient self-regulating mechanisms that ‘kick in’ to keep these and other vital minerals at levels suitable for maintaining life. With the correct ratio of potassium to sodium being so vital for life to continue, when the horse ingests too much potassium this triggers the adrenal glands to secrete the aldosterone hormone which in turn tells the kidneys to get rid of potassium and conserve sodium.

Horses, like us, handle temporary spikes of potassium well but it seems when it becomes continuous or chronic then the body’s ability to self-regulate becomes compromised. The ensuing electrolyte imbalances start the cascade of health and behavioural problems we see in our domestic grass-fed horses.
Health Check

Thank you Nevada!


*Thanks to Nevada for demonstrating classic Grass Affected Behaviour!

Would you ride this horse?

Take a look at Nevada's page to see how different he is when he has the correct diet...