Some horses start showing signs of aging as early as 15 years old, while others remain very active and healthy well into their twenties. The individual differences are significant, so it’s essential to closely observe your own ‘senior’ horse before determining what they should eat.

An older horse is still just a horse

In principle, older horses don’t always need a different diet than younger horses, but if your horse has ailments or weight issues, it may be wise to make adjustments. Older horses may experience stiffness and arthritis, a more worn-down set of teeth and/or weaker chewing muscles, difficulty with thermoregulation (making them more sensitive to cold or heat), insulin resistance (PPID and/or Cushing's), and inflammation. Even if they are otherwise healthy and still in work, these issues can arise. You need to monitor these ailments when determining the feeding strategy for your senior horse. It’s also important to remember that, just like with humans, a healthy lifestyle keeps your ‘golden oldie’ fit for longer. This means not just the right feed but also plenty of (free) movement and interaction with peers. Another good thing to know: Older horses require the same amount of vitamins and minerals as younger horses. A balancer is always a good idea.

Too skinny or too fat?

Research in the United Kingdom has shown that about eight percent of senior horses are underweight, while over 10 percent are overweight. Overweight is thus a relevant issue for senior horses too. It can lead to problems such as lameness, laminitis, insulin resistance, or equine metabolic syndrome (EMS). Overweight senior horses also often have increased inflammation levels. In such cases, weight loss is a good solution. However, if your senior horse is (sometimes) too thin, factors such as kidney problems, liver disease, and pain (e.g., from cervical arthritis) should also be ruled out. A painful neck can make it uncomfortable for a horse to eat from the ground. Diarrhea, infections, and inflammations are other signs that weight loss might not solely result from diet. There’s evidence that worm infestations earlier in life can leave scar tissue in the intestines, which, in some cases, reduces nutrient absorption, leading to weight loss in older horses.

Cold and heat

Weight loss can also occur during cold winters and hot summers, partly due to older horses’ poorer thermoregulation. Therefore, during winter, it’s wise to pay extra attention to your senior horse’s diet. Many people, for example, provide a soaked forage substitute in the colder months. This is also easier to digest since it doesn’t require as much chewing effort. Forage is crucial because heat production occurs in the large and cecal intestines, where the fibers in forage are broken down by gut bacteria to release energy. Special senior horse feeds are usually most beneficial for horses that are significantly underweight or have been in the past. For horses that haven’t previously lost weight during the winter, special senior products are often unnecessary to maintain their weight. Again, focusing on the individual horse is key.

Check the teeth!

If a horse has very poor teeth or conditions such as periodontal disease, this might also necessitate feeding more liquid foods. Some horses may also develop arthritis in the temporomandibular joint, which can make chewing and swallowing more difficult. For all older animals (including humans), muscle mass decreases with age, and this also applies to chewing muscles. Older horses therefore take longer to chew the same amount of hay compared to younger horses.

Management

What to consider for the senior horse:

• The horse should have a dry place to stand and lie down but not be confined to a stall for long periods to ensure enough free movement.
• The horse should be able to protect itself from harsh wind, rain, or snow; in summer, shade is essential.
• Proper dental care and an appropriate deworming schedule are vital.
• Horses with excessive hair growth can be clipped in summer if they get too hot.
• Horses need to drink adequately year-round, so ensure sufficient water sources are available at the right height (especially important with cervical arthritis).
• Monitor your horse and regularly check its body condition score; adjust the feeding plan based on what you observe, particularly during extreme weather.
• A stable herd where the senior horse isn’t bullied is beneficial.
• Regular hoof care is crucial.
• Veterinary checks are essential if you suspect conditions like PPID or insulin resistance.

Nutrition: Four groups of senior horses

A British study on the nutritional needs of older horses identified four groups, each with different requirements. Which group does your horse belong to?

Group 1: Healthy, active horses at a normal weight
These are senior horses that are still healthy, maintain a good weight, and are still used for activities or breeding. These horses only require a standard feeding regimen tailored to their work or breeding, just like adult horses. No changes are necessary.

Group 2: Active horses prone to overweight
Senior horses that are still active but tend to gain weight fall into this group. For these horses, preventing obesity is key. Balancing this with the risk of weight loss—especially in winter and for those with dental issues—can be challenging. Many senior horses, particularly those without a history of laminitis, are better off entering winter slightly heavier. However, if a horse exits winter overweight, it’s wise to help them shed some pounds.

Group 3: Clinically healthy horses prone to underweight
These are healthy senior horses that struggle to maintain a healthy weight on a standard adult horse diet. Ensure their teeth are checked, rule out worm infestations, and have kidney and liver values assessed by a vet. If all is well, gradually increase their feed, focusing on options that don’t spike insulin levels. Examples include more grass hay, soaked grass pellets, sugar-free beet pulp, or soybean hulls. Avoid adding excessive starch or sugar, especially in horses prone to laminitis. Consider adding oil as an energy source. Flaxseed oil is popular, but salmon oil has a better fatty acid profile and is highly palatable for most horses. Do not exceed 1 ml of oil per kg of body weight without consulting a vet or nutritionist. Avoid too many grains or standard pellets; if grains are included, ensure they are heat-processed (as indicated on the label). Grazing with sufficient grass is ideal, particularly in late summer and autumn, as it prepares horses well for winter.

Group 4: Senior horses with one or more medical conditions
Horses with medical issues need treatment tailored to their condition. Regarding diet, the priority is that the horse can and will eat what’s provided. If the feed also meets their nutritional needs, you’re doing well. For horses with PPID—especially those with a history of laminitis—low-sugar hay is essential. Hay can be soaked for three hours to reduce sugars, but soaking also leaches some energy, which might lead to weight loss. These horses need a good balancer with vitamins, minerals, amino acids, and omega-3 fatty acids. Magnesium supplements are also often beneficial. For horses with dental problems, offering softer and shorter hay is a good idea. Long, coarse-stemmed hay may no longer be manageable for some seniors. Grazing is ideal if feasible; otherwise, soaked forage replacements like grass pellets or beet pulp can be used. Be cautious with horses prone to choking or esophageal blockages—they may need their feed to be even softer and more liquid-like.

Supplements

In addition to the previously mentioned omega-3 fatty acids (e.g., salmon oil) and magnesium, vitamin C is also essential for senior horses. Older horses are more prone to respiratory conditions, and their vitamin C levels decline. While younger horses produce their own vitamin C, this process becomes less efficient with age. Vitamin C is crucial for the immune system. If your horse develops a cough, herbal extracts can help support respiratory health. If there’s little or no fresh grass in the diet, supplementing with vitamin E is also wise. Vitamin E plays an essential role in keeping muscles supple and supporting the immune system.