Laminitis!

Briony Witherow, has practical nutritional advice for preventing and managing laminitis

Whether you’re managing a horse or pony that has previously had laminitis or, one that may be at high risk due to metabolic issues, obesity or other factors, the nutritional approach is the same. Management for low starch and sugar rations should be approached firstly by addressing the forage (hay/haylage/pasture), then by adding concentrate feed as required. For both aspects, feed, and general management (including owner compliance) should be considered.

Forage

This should form the basis of the ration and is arguably the most challenging. As forage (pasture, hay, haylage) forms the foundation of the ration (a minimum of 1.5% bodyweight dry matter), it is likely to be the greatest source of calories (energy) and sugar in most horse’s diets. Forage is hard to regulate and is often furthermore limited by the owner’s facilities or flexibility to buy and manage their own supply. For this reason, while the following outlines an ‘ideal’ for those at risk of laminitis, the practicalities of horse ownership mean that ticking all ‘the boxes’ is often unrealistic.

Conserved forage

While the ideal forage is not always possible to source, it is good to have an idea of an appropriate nutrient specification as an end goal. The more appropriate forage you can source, the easier the management and the less reliant we are on concentrate feeds – that goes for all horses, not just laminitics. Selecting the right hay or haylage may also allow for greater volumes to be fed, helping to avoid ‘hangry horses’ while also having the potential to facilitate weight loss¹ ².

The ideal specification of hay or haylage should be low (<10-12% DM) in non-structural carbohydrates (NSC (starch and sugar)); high in fibre (NDF 60-65%; ADF 35-45%) and, where weight loss or control is required, low in calories (energy) (≤8MJ/kg digestible energy). While hay or haylage arguably may meet these requirements, hay can provide greater flexibility with the option of soaking and, tending to be less palatable, may occupy the horse for longer³ ⁴. Alternatively, where haylage is analysed, it can be combined with straw to provide an appropriate ration with regards to calorie and sugar content.

Dealing with less-than-ideal forage?

If you are unable to source your own forage or, like many of us, in yard situation where it is simply not possible to have multiple different hays and haylages for induvial horses, this is still workable.

If you have a good consistent supply of forage, the first step is knowing your starting point. Taking a small sample of around 10% of the bales and sending off for a basic analysis will give us an idea of suitability. As a guide, a basic Near Infrared Reflectance Spectroscopy (NIRS) analysis starts at around £20 and, will give you an idea of calorie and fibre (ADF and NDF) content and an estimate of sugars. For a more accurate analysis (suitable if you have significant stock from the same batch) wet chemistry, starting at £60 this will give you a full analysis, including an accurate breakdown of starch and sugars.

If the forage supply is inconsistent or you receive analysis that indicates the forage to be unsuitable, there are still options available

Soaking hay is one option. Recommendations on soaking time varies and is ultimately influenced by the starting point (i.e., original nutrient specification) and soaking environment. Soaking hay in clean, fresh water from 1 to 12 hours⁴ ⁵ ⁶, has been shown to reduce sugar content, however caution should be taken with lower soak times where no analysis is present and soak times should be adjusted to reflect weight and condition. In addition to total soak time, other elements of this practice can be adapted to maximise sugar loss. For example, warmer water temperatures, agitation of hay while soaking and increased water volumes¹ ⁵. To account for dry matter losses during soaking, pre-soaked hay rations should be increased by 20% to ensure appetite is met¹.

Another option which can be employed alongside soaking, or in combination with an appropriate (ideally analysed) forage is combining the ration with straw. Replacing up to 30% of the forage ration with good clean straw can help to reduce overall calorie (energy) intake while helping to satisfy appetite ¹ ⁷ ⁸.

Pasture

Pasture management will ultimately depend upon the individual horse or pony. For acute cases of laminitis complete removal of pasture is often necessary in the short-term. Where obesity is also a factor, research indicates, programmes that exclude pasture appear to facilitate greater weight loss⁹. For horses with a history of laminitis, metabolic or other factors that increase laminits risk, it is important to consider that even if body condition and weight is well managed, managing pasture to limit sugar intake is essential ¹⁰ ¹¹ ¹².

No single recommendation can be provided when it comes to pasture restriction. Available options are typically kerbed by facilities and other practicalities¹³ ¹⁴. Furthermore, as all horses (and owners!) are individuals, trial and error is, often required to find a solution that works for both. Options include strip grazing; grazing muzzles, stabling, dry lots (grass free turnout) and track systems based around innovative resource placement¹⁴ ¹⁵.

In addition to this, certain environmental conditions can reduce sugar accumulation in pasture. Being aware of these helps to increase awareness of when sugar levels may be high and to approach day-to-day turnout tactically with environmental conditions in mind. Conditions which may results in reduced sugar accumulation include:

• Overcast days and pasture shaded by trees or hedges. Under these conditions light intensity is lower, which reduces the plant’s ability to produce sugar¹⁶ ¹⁷.

• Early morning or late evening turnout can be more appropriate. Sugar concentration typically builds during the day and starts to drop a few hours after sunset and rise again by 10am the following day¹⁶.

• Healthy, stress-free grass accumulates less sugar. Avoiding situations which may cause stress (through inhibiting growth but not photosynthesis), such as drought, poor soil fertility and sunny conditions on frosted pasture is key¹⁶ ¹⁷ ¹⁸ ¹⁹. Furthermore, conditions in the spring/autumn where overnight temperatures dip below 5°C followed by warmer days, also predisposes to NSC accumulation¹⁷.

References

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