Colic
Fresh Grass & Colic
Colic is one of every horse owner’s worst nightmares.
The more you understand about it the better.
For signs your horse has colic: https://www.petmd.com/.../condi.../digestive/colic-in-horses
There are multiple causes of colic.
Some are very preventable if you are aware.
In Autumn & Spring the risk goes up.
The common denominator for these ‘seasonal’ bouts is “fresh” pasture...
* Horses are being turned out on it with no gradual introduction - as is the practice with ‘rotational’ grazing
*Recent high rainfall has caused a growth spurt.
*Horses are offered hay but won’t eat it because there is too much grass.
*Mineral imbalances from the grass which directly affect gut motility are not being addressed in daily feeds
*Dehydration combined with electrolyte imbalance. Low sodium can reduce water intake, which can lead to hardening of faeces and impaction colic.
First things first:
Colic is a life-threatening emergency.
If your horse shows any signs of abdominal discomfort — CALL YOUR VET IMMEDIATELY.
Do not hesitate, time is of the essence!
Here is a link to helpful information; https://www.horseeducationonline.com/symp.../colic-in-horses
How does “fresh” grass cause colic?
It’s not just about sugars.
Mineral/electrolyte imbalances and lack of fibre have consequences on Gut Motility:
*The vagus nerve, which controls digestion doesn’t work at 100% efficiency
* Gut motility slows down which leads to a build-up of gases
*You will hear loud gut noises from several metres away
*Being full of gas, a section of the small intestine can displace and wrap around other structures in the abdominal cavity (splenic ligament for example – strangulation type colic)
* Impaction colic - when gut motility ceases altogether (known as ‘Ileus’) there is danger of a blockage in the intestine
*Changes to the Microbiome – any alteration to gut motility changes the ‘soup’ - the living environment for the gut flora – this will favour some populations and destroy others
* The lining of the intestinal tract can become inflamed leading to colitis, leaky-gut and risk of endotoxemia
*Spasmodic colic – spasms/cramping of the smooth muscles of the intestinal tract.
Reduce the risk by increasing resilience in your horse:
Become familiar with your horse’s normal gut sounds while he is well. Rumbly, gurgly, tinkly noises can be heard constantly in a normal horse when you get close with your ear.
Learn about gut sounds here:
https://madbarn.ca/gut-sounds-in-horses/
* Avoid ‘Rotational’ grazing, (as is practiced for groups of horses) because it means horses are regularly exposed to ‘fresh’ paddocks
* Introduce any ‘fresh’ grass slowly (start at 10 - 15 mins/day, build up)
*Prioritise fibre intake – have horses eat hay before going out on pasture
*Help balance minerals by REDUCING potassium intake (restricting green grass, being mindful of items like lucerne, copra, soy-bean meal, kelp, molasses)
*Add salt to feeds (10g per 100kgs)
*Add appropriate calcium/magnesium supplements*** to address mineral imbalances from the grass which directly affect gut motility
Be extra cautious after rain or seasonal change - this is when pasture imbalances peak
In one case where we analysed pasture causing repeated bouts of gaseous colic had:
• Dry Matter: <20%
• Crude Protein: 35.6% (VERY HIGH)
• Potassium: 3.8% (very high)
• Sodium: 0.07% (very low)
• DCAD: extremely high at 508
• Soluble Sugars only 6.7%
Even with low sugars — it still caused multiple colic episodes.
This horse had no more bouts once removed from this grass and fed more hay
Colic is an Emergency!
Any form of colic is an emergency - call your veterinarian immediately!
There are numerous causes of ‘abdominal pain’ or ‘colic’. Because some of them are life-threatening always call your veterinarian immediately should you observe any of the following signs:
Pawing, rolling, looking around or kicking at the abdomen, bloating, sweating, distress, uneasiness, agitation, loss of interest in food and water, unusual postures like sitting or standing stretched out, louder than normal gut noises or the absence of gut noises.
The last two are significant.
Gut Noises & Colic ...
Under certain climatic conditions - for example with the onset of autumn, when the days are still warm, the night-time temperatures are dropping along with Autumn or drought breaking rain, which alter the chemical composition of the grass an increase in the incidence of certain equine ‘colics’ is common.
At a time you know your horse is well, familiarise yourself with his normal gut sounds by standing at his side keeping his head bent slightly around towards you. Place your ear against his flank just behind the ribs. You will hear a variety of gurgly, rumbly sounds. These are the normal sounds of the digestion process.
Check both sides.
There are multiple reasons for a horse to colic, a few of which can be associated with the changes to the grass with a seasonal change.
Gaseous Colic
The mineral imbalances arising from these changes in the grass, not only have the potential to affect the skeletal muscles, but also the smooth muscles of the digestive tract. These smooth muscles create the 'wave -like' movements of the digestive tract (peristalsis) which push the food through.
If peristalsis slows down, gas builds up in the intestine, most commonly in the large intestine and/or caecum. The gas stretches the intestine, causing discomfort and pain.
You will hear louder and gurglier than normal gut noises sometimes audible from a few metres!
Don't take this type of colic lightly as the danger is that portions of the intestine that are filled with gas, can displace and wrap themselves around other parts of the gut causing the blood supply to be cut off. (Twisted gut)
Forage tests taken from pasture consumed by horses suffering repeated bouts of such colic revealed very high potassium:sodium ratios (for example 54, when it should be no higher than 5)
CALL YOUR VETERINARIAN
(Don’t delay with any colic)
Some diet changes may be necessary to prevent further bouts.