Nutrition CBD July 2017

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Feeding the senior horse or pony

By Clare Barfoot RNutr 

The senior horse population across the developed world is increasing. This is primarily because of improved healthcare and nutrition but also because the reason we keep horses has changed, with the majority of horses and ponies now being pets rather than working animals. 

This means that owners are much more committed to providing the best care they can in order to keep their older horses as fit and active as possible.

Age is not just a number

Age can be measured in three ways: Chronological age which is simply the horse’s age in years can give you some information but it can be misleading as some horses, just like people, age more or less successfully. 

Physiological age uses markers of ageing and perhaps is the most accurate way to measure ageing, but this whole area is still being researched. 

Another way to look at age is demographically; the age at which there is 25% survivorship within the overall population. For horses in the UK in 1999, this was 15 years old. However the cut-offs vary per country with a survey in Australia in 2010 finding 38% of the population was over 15 years old. 

However you look at age, one thing is for sure, it’s highly individual with most owners using a combination of chronological age and physiological age to ‘judge’ if their individual horse is old and needs a change in feed and/or management.

The science of ageing – what we know about the horse

Digestion and gut function

Other species including rats and humans show gut and gut based immunity problems as a consequence of ageing. Although little work has been carried in horses, and there have been some conflicting findings, it’s generally thought that, under most practical feeding situations, healthy older horses that have good teeth and appropriate worm control don’t have any reduction in digestive efficiency compared with their younger counterparts.

However, work undertaken by Dougal et al in 2014 did show reduced diversity in bacterial species in the hindgut of aged horses. From a practical perspective, this could mean that older horses may be potentially more sensitive to dietary changes. Therefore it is very important that all grazing, forage and feed changes are carried out slowly to avoid digestive upset.

Body condition and muscle tone

Many horse owners will tell you that their older horse loses weight more easily and has lost muscle tone. However these observations may not be a direct effect of ageing. 

A reduction in exercise has a larger effect on muscle tone than ageing per se. With regard to bodyweight changes, equine obesity unfortunately brings just the same challenges to the senior horse population as it does to the general horse population. Two recent surveys, one in the UK and one in the US, found that 10.5% and 28% respectively of the older horse population were found to be overweight, potentially increasing their risk of age-related disease. 

Temperature control

Older horses do not cope as well in extremes of temperature compared with younger horses, in the same way that humans often become more sensitive to heat and cold as they age. 

So, in colder months, consider rugs, shelters, stabling and during hotter months concentrate on keeping older horses cooler with clipping, hosing down and making sure they have appropriate shade.

Immune defence 

Just like humans, horses do show signs of age-related declines in immune function which leaves them more susceptible to infections. This effect is exacerbated in overweight and obese horses and is another reason to keep them lean!

What to consider when feeding an older horse

Fundamentally, feeding a healthy older horse is like feeding any other; only when your customers start to notice age-related health issues should they consider adapting their management and feeding regime. 

Below are some of the considerations they may have to take into account:

Dental issues

There is a saying that horses survive as long as their teeth and this is certainly true in the wild. In a domestic situation, dental issues are one of the main reasons for weight loss in older horses. It can be recognised through a lack in condition, digestive issues such as colic, choke, quidding, bad breath, lack of appetite, long fibres in the droppings or obvious pain and discomfort when eating and chewing. 

If these signs are not picked up, some owners will increase the compound feed. But the fundamental issue that needs to be addressed is how to replace the long fibre forage portion of the diet appropriately. 

Insulin dysregulation

Insulin dysregulation, which often encompasses insulin resistance, is associated with ageing and is often a core component of Cushing’s disease/ Pituitary pars intermedia dysfunction (PPID). It is also thought to be involved in laminitis and Equine Metabolic Syndrome (EMS), which are more prevalent in middle aged and senior horses. 

On this basis, an appropriate low non-structural carbohydrate diet is beneficial in the management of all senior horses and ponies. 

Joint disease

Pain from general joint disease can affect appetite as well as the horse’s desire to graze and eat from a haynet if there is any pain in his neck and/or fore limbs. Therefore pain management should be discussed with a vet to maintain good welfare. 

Herd dynamics

As horses age, herd dynamics become increasingly important. Horses benefit in many ways by living in a herd environment, but as they get older they may be pushed down the pecking order by younger animals which means they may lose out when it comes to feed and water. 

Look out for signs of bullying and feed horses separately if needed. Ideally provide a large water trough or more than one water supply in the field too.

Practical feeding advice

Older horses can be perhaps divided into four categories which are described below along with some practical feeding recommendations:

• Young at heart

These are horses or ponies that are in good body condition and are often still ‘in use’. They will not have any apparent age-related conditions and are maintaining bodyweight and health status on their ‘normal’ adult ration.

Feeding recommendations for your customers

Maintain them on their current ration assuming it is balanced for their needs. Continue to monitor condition using a body condition scoring system, maintain a good worming and vaccination programme and have their teeth checked regularly. 

But more importantly look out for any gradual changes that may suggest age related conditions are developing. Many horses and ponies that are retired or in light work will maintain their bodyweight on good quality pasture and forage alone so won’t need any supplementary feed. If this is the case, a feed balancer is ideal to provide a balanced diet. Senior balancers often contain higher levels of protein, antioxidants and joint support so are ideal in this situation. 

• Old and overweight

This is the ‘middle-aged spread’ character; he will be clinically normal but overweight or obese due to reduced physical activity, his type or because of over feeding.

Feeding recommendations for your customers

Weight loss is the priority here and a calorie restricted diet needs to be put in place asap! Depending on the horse or pony’s current management and diet, the key things to consider are a restriction in grazing, removing all supplementary energy giving feeds, switching to a lower calorie hay (although do not restrict intake to less than 15g per 1kg bodyweight (dry weight) without veterinary advice), and soaking it for at least three to six hours in tepid water. 

A feed balancer designed to complement a calorie restricted diet is ideal in this situation as it will balance the diet without providing unwanted calories.

• Aged but with a tendency to lose weight

These are horses and ponies that are again clinically normal but struggle to maintain weight on their ‘normal’ adult ration particularly during the winter months.

Feeding recommendations for your customers

Firstly, a general health check to rule out anything underlying would be a good idea. After that, increase the calories in the diet; which feed you choose will depend on the horse’s current diet. Appropriate options may include a senior feed which is likely to provide more calories, protein, oil and phosphorus than their current ration. 

Keeping the sugar and starch restricted will be of benefit, as it will help maintain insulin sensitivity and optimum gut health. Look for feeds that provide energy through highly digestible fibre sources (sugar beet, alfalfa and soya hulls) and oil.

• The golden oldie – the true geriatric

This is the old horse that does have some age-related conditions that require careful management.

Feeding recommendations for your customers

Firstly it’s important to make sure underlying health conditions are checked and monitored by your vet and then welfare can usually be greatly increased with appropriate dietary management. 

Below are some tips to help manage two of the most common conditions we see in older horses:

Cushing’s disease (PPID)

This condition needs to be managed in a similar way to laminitis, namely restricting the level of non-structural carbohydrate (water soluble carbohydrate plus starch) in the overall diet to less than 12% in the dry matter. This will often mean a restriction in grazing and choosing an appropriate low NSC forage. Depending on the horse’s condition, choose a feed suitable for a laminitic and if weight gain is required, contact a nutritionist for advice. 

Dental issues

Choose softer, easier to chew hays or consider using a chopped hay replacer. However if no long fibre can be managed, a complete soakable diet will have to be provided. There are a few on the market that can be soaked into a mash, or you can soak high fibre cubes alongside sugar beet, hay or alfalfa cubes. The most important consideration is that you will need to replace at least 15g per 1kg of your horse or pony’s bodyweight per day; this is 7.5kg (dry matter) per day for a 500kg horse. Ideally this needs to be fed in five meals per day, fed four hours apart.

Summary

Healthy, older horses with no age-related issues can be fed just the same as their younger counterparts as long as their diet is balanced for their needs and maintains them in an ideal body condition. 

However, once you start to notice failing dentition, joint disease or age-related conditions such as PPID, the diet should be adapted to maintain wellbeing, body condition and to prolong quality of life. 

Luckily, with so many different feeds on the market, there is an appropriate diet for every senior horse no matter what their individual needs. After all, they deserve it for all the years of fun they have given us!