Defining the ‘nutritionally senior’ horse
When does a horse become a ‘senior’? In general, horses between 18 and 20 are considered to be approaching their senior years. However, a better definition is when a horse becomes ‘nutritionally senior’. A nutritionally senior horse can no longer eat a normal diet and maintain body condition, and typically has one or more of the following: decreased nutrient absorption, dental problems and increased sensitivity to stress. The description ‘geriatric’ in a horse relates to diseases and disorders caused by ageing, not by a specific number of years spent on this earth.
Digestive and metabolic changes in the senior horse
Decreased nutrient absorption: Intestinal parasites cause scarring of the digestive tract which decreases nutrient absorption. Improvements in de-worming products have delayed and minimised this damage, but over a lifetime, it still occurs. The horse’s digestive tract begins to lose efficiency with advancing age too, and research has shown that nutritionally senior horses require additional protein, phosphorus, and certain vitamins.
Dental problems: As horses age, their teeth wear down and fall out, making chewing difficult. While loss of teeth cannot be prevented, proper dental care can delay problems. The digestive process begins in the mouth by reducing feed to a suitable size for digestion, so without proper chewing the horse cannot effectively digest food, leading to digestive upset, weight loss and nutrient deficiency. Horses with dental problems will often spill grain or wad up forage into partially chewed balls and drop them on the ground. Horses with these issues need alternate sources of pasture and hay, forage products including chaff and fibre nuggets, such as HYGAIN® FIBRESSENTIAL®, and complete feeds, like HYGAIN ZERO® which can be fed as a wet mash to minimise choking.
Stress: Our aged equines are very sensitive to stress, which can come in the form of changes in temperature, housing, the herd pecking order or pain. To alleviate weight loss associated with stress, senior horses should have shelter, waterproof blankets and be kept with a consistent group of horses in familiar surroundings. They’re particularly sensitive to the cold when their layer of insulating fat decreases, and they find it hard to chew adequate amounts of fibre. Fermentation of fibre in the hindgut produces heat, keeping them warm in cooler weather. Senior horses are also sensitive to changes in their surroundings, so a sudden change in paddocks or routine can cause weight loss, as can adding or removing horses from the herd, which may send the old one to the bottom of the pecking order. Horses in pain from old injuries or arthritis will suffer from loss of appetite and drop in body condition.
Overweight: Not all older horses are hard keepers; some will hold their weight easily and may actually become too heavy due to lack of exercise – which is equally detrimental to their health, by stressing their bones and joints and aggravating any existing lameness such as arthritis and navicular syndrome. Allowing them ample turnout time will provide some exercise and help them to maintain healthy muscle tone and body condition.
Disease: Senior and geriatric horses are subject to many age-related diseases like chronic infections, liver or kidney failure, anaemia, Cushings disease and respiratory problems. These all require veterinary treatment and proper nutrition is key to recovery and strengthening the immune system.
A senior horse’s diet requirements
When a horse has been identified as nutritionally senior, it must be fed as an individual. The goal is to maintain an optimal body condition with the shoulders and neck blending smoothly into the body, the ribs not visually distinguishable but easily felt, and a flat back (no crease or ridge).
The most important component of the diet is forage (hay/pasture). Many old horses maintain a good body condition on pasture, but lose condition when forced to rely on hay − this is often due to their inability to chew properly. Replacing baled hay with hay that has been ground and compressed into a nugget will help digestion. Soaking these nuggets will soften the product and enhance consumption.
Energy requirements: Senior horses in good body condition are less active and need maintenance energy requirements. However, if the horse has difficulty keeping weight on, you’ll need to increase its calorie intake. Energy-dense feeds, namely HYGAIN® RBO® Equine Performance Oil® and HYGAIN TRU GAIN® (an extruded high fat supplement) are ideal for weight gain. Full feeds, such as HYGAIN® SENIOR® or HYGAIN TRU CARE® are advisable as they provide conditioning energy from quality sources such as highly digestible fibre, micronized barley and HYGAIN RBO.
Protein requirements: Protein is essential as senior horses with inadequate protein intake will break down muscle tissue so the body has enough protein to function. Muscle wasting is common in aged horses who are not getting enough protein. When creating feeds for seniors, the protein content is similar to what would be fed to a yearling. Both HYGAIN® SENIOR® AND HYGAIN TRU CARE® provide high quality protein sources in adequate amounts.
Mineral requirements: Limited research has been conducted on senior horses’ vitamin and mineral requirements, but they would benefit from supplementation of vitamins E, B and C to help boost the immune system and digestive function.
Physical signs of the aged horse
Through good care and optimal nutrition we can improve the quality of life of our senior horses and extend their lives even further. Some common physical signs of ageing that require nutrition management are:
- loss of weight
- decrease in body condition
- loss of muscle tone and mass over
- sway-backed appearance
- chronic diarrhoea and dehydration
- reduced mobility and agility
- greying of muzzle and coat
- decrease in coat and hoof quality
- reduced fat deposits above the eyes
- dental problems