Sirius’ Story – Laminitis Risk

Meet Sirius, a 3 years old, Welsh Mountain Gelding who belongs to Kate (one of our Equine Vets). He has been lazing about this winter, doing far too well.
The sunny weather means laminitis risk is severe and for equines like Sirius the risk is very high.  Measures to restrict grazing and promote weight loss should be implemented now.

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Sirius – Laminitis Risk

Sirius body condition

Body Condition

Sirius was body condition score 4/5 with a groove along his back, heavy crest and dimples above his tail. Being fat increased his risk of laminitis. Follow his progress as he went on a diet.

Sirius’ diet – hay

Sirius - eating hay

To reduce a horse’s weight, we start a diet of 1.5% body weight in dry hay every 24 hours. If a horse is overweight, we calculate the weight halfway between their weight now

and the weight we are aiming for. Sirius weighs 275kg now, he should weigh around 225kg, so we use 250kg to calculate hay. 1.5 % of 250kg is 3.75kg of dry hay over 24 hours. We can divide this into multiple small nets.  By soaking nets in water for 12 hours, we reduce the calorie content to further enhance weight loss.


Sirius grazing

Horses at grass only eat for about 16 hours per day. They do not need to eat constantly and they naturally rest between 10pm and 6am. Stabled horses tend to eat whenever food is available because they can’t socialise or exercise (like us on lockdown), but they don’t need to. Feed should be provided with most offered between 6am and 10pm and none after that. Splitting the forage into 3-4 small amounts will reduce the time without any food during the day.  Double nets or trickle feeders can be used but where possible feed forage loose on the floor as it is better for dental and respiratory health.


If you are grazing your horse whilst reducing his weight, you can use restricted time out, over grazed paddocks, restricted area or track systems and muzzling, to reduce the amount of grass consumed. Overnight grazing when sugar levels are lowest (midnight to 4am) or more conveniently, 10pm to 6 am, is a good option, as this coincides with the naturally reduced food intake period.  But the total length of turn out may be too much for greedy individuals.  All options have advantages and disadvantages. Remember grass is high in non-structural carbohydrates and low in protein and nutrients (like fast food for ponies).

Sirius turining outTurning Out

If overweight horses or ponies are turned out for part of the day, the amount forage given in the stabled must be reduced.

As horses eat for 16 hours in a 24 hour period, if a horse is turned out for 4 hours that is 1/4 of the feeding time, so reduce the total amount of hay fed by 1/4. Horse consume more in the first hour if grazing, so for those on 1-2 hours turn out only, reduce hay by 1/8. For a 300Kg pony (who’s ideal weight is 250kg), dry hay allocation is 4 Kg daily. Turnout for 1 hour, reduce to 3.5Kg daily. Turnout for 4 hours, reduce to 3 Kg. These are approximate starting points, next we will look at monitoring weight and adjusting feeding.

Sirius - weightapeHow do we tell if the diet is working?

As you see your horses and ponies every day, visual assessments tend to be unreliable. Changes in weight can be disappointing.  Muscle weighs more than fat and body condition scores take a huge amount of effort to change, particularly when they are over 4 out of 5. Girth measurements, using a weight tape if available, are the best way to track weight loss. Measure once every 2 weeks, always at the same time of day (measurements change with feeding). There is a video on the website, if you haven’t done it before.

What matters is whether the tape is coming in or going out (weight loss or gain). If the girth measurements are reducing, continue on current feeding. If the girth measurements are going up or staying the same, reduce the total amount being fed by 1/4. For the 300Kg pony having 4 Kg hay a day, reduce to 3Kg. Horses should never receive less than 1% Of body weight in dry matter per day, so for 300Kg pony, 3 Kg of hay is the minimum that should be fed. Don’t forget to factor in grass consumption when turned out. Alternately, grazing time could be reduced or a muzzle or more restricted access used.

If you are uncertain of your calculations, we can work out a feeding plan for you and give advice on changes, as the weight loss plan progresses.

Equine nutritionNutrition

Most horses’ diets are low in protein, minerals and vitamins. The diets we use to reduce body condition are deficient in nutrients, especially when prolonged hay soaking is involved. Low protein levels in a diet slows the speed of weight loss. By providing protein, vitamins and minerals, we can increase weight loss, maintain muscle mass and keep our horses and ponies fit, well and competition ready. Low calorie balancers are a good options, providing everything that is lacking, in one feed. Alternatively non-molassed Alfalfa provides protein, and vitamin/ mineral supplements can be used. Non- molassed, complete, low calorie feeds can be used for greedy animals. There are many options available but if you are overwhelmed by the choice, you can speak to your vet or consult the nutritionists at your preferred feed brand for advice.

Sirius – 4 weeks into diet

Sirius after 4 weeks4 weeks into Sirius’ diet and he has lost fat from his back and rump. He is now body condition score 3.5/5. Horses lose weight from back end to front end, so they tend to go a bit uneven initially, before evening out again. Ideally horses and ponies body condition should be 2.5 to 3 and should be achieved through gradual, sustained weight loss. Sirius still has some way to go…

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