A vet recommended nutritional approach to manage your horse or pony with PPID

Around one in five horses over 15 has PPID [1]. That's not a rare condition. Most horse owners will face it eventually. The disease disrupts a key hormonal brake in the brain, sending cortisol levels chronically high and reshuffling how the body stores fat, burns energy, and builds muscle. Medication helps. But what your horse eats every day is just as consequential, and it's the variable owners have the most direct control over. This guide breaks down how to adapt the diet based on body condition, insulin status, and age.

Why PPID changes your horse's nutritional needs

In a healthy horse, dopamine produced in the hypothalamus keeps pituitary hormone output in check. In PPID, the dopaminergic neurons degenerate and that check disappears. Excess ACTH drives the adrenal glands to overproduce cortisol continuously [1]. Three things follow.

Muscle breakdown accelerates. Cortisol overactivates the ubiquitin-proteasome system, which degrades muscle protein faster than it is rebuilt. Fat distribution shifts, with abnormal deposits above the eyes, around the crest, and at the tailhead. And insulin dysregulation becomes a real risk: after meals, more sugar enters the bloodstream, the body overcompensates with insulin, and cells gradually stop responding to it [2, 3]. That last point matters because the downstream consequence, if left unmanaged, is laminitis.

A standard ration was designed for a horse whose metabolism works normally. In PPID, it often does not.

Before adjusting the ration: what to evaluate first

A thorough assessment prevents problems from worsening after dietary changes. Before adjusting anything, take stock of:

• Current diet: total energy, sugar, starch, and protein intake, so you and your vet can see where adjustments are actually needed.
• Housing and pasture access: type and quality of hay and grass available, and whether the horse competes for feed in a group.
• Medical history: previous or ongoing conditions that the new plan must support, not undermine.
• Co-existing conditions: dental problems, arthritis, or parasite burden each change what and how a horse can eat.

1. Feeding the overweight horse with PPID

A Body Condition Score above 6 is overweight. The basic principle for weight loss is the same as in any horse: energy in must be lower than energy out. What changes in PPID is the margin for error. Even a modest excess of sugar or starch raises insulin further, which promotes fat storage and makes fat mobilisation harder [2]. There is very little room to be "approximately right" with feed choices here.

1. Reduce energy intake and increase exercise.
2. Cut feeds high in sugar and starch: grains, young grass, and molasses-containing products.
3. Consider levothyroxine sodium under veterinary supervision if weight loss is strongly resistant. Some horses simply cannot mobilise fat reserves through diet and exercise alone.

Use hay nets with small holes or a grazing muzzle to slow intake and prevent hunger spikes. Adding straw to hay lowers energy density without cutting total volume. One caveat: older horses with arthritis or neck stiffness often struggle with elevated hay nets, and ground-level hay may be more practical.

A vitamin and mineral balancer such as ESTE Balancer fills the micronutrient gaps that appear when the ration is primarily roughage. Steady&Stable from Curafyt, containing Berberis vulgaris, supports weight management and helps regulate sugar metabolism.

Protein deserves specific attention. Lysine, threonine, and tyrosine are critical for maintaining muscle mass and supporting dopamine synthesis, which is depleted in PPID. Body&Build from Curafyt provides targeted protein support. Combine with light, consistent exercise to counter the cortisol-driven breakdown.

2. Feeding the underweight horse with PPID

Underweight in PPID horses is not always easy to spot. Hormonal changes alter fat distribution and muscle development in ways that can obscure a low BCS. A horse that looks "just old and thin" may have significant muscle loss that's easy to miss until it's quite advanced. The cause of the weight loss determines the fix. Simply feeding more is often not the answer.

• Dental problems: Check teeth and address chewing issues such as quidding before assuming the ration is insufficient.
• Parasites: PPID horses can be more susceptible to parasite burden. Strategic deworming every 3–4 months is recommended.
• Social hierarchy: lower-ranked horses in a group often receive less feed or eat too quickly under stress. Separate feeding resolves this.
• Muscle breakdown via cortisol: elevated cortisol overactivates protein degradation pathways. The fix is targeted protein supplementation, not just more calories.

Alfalfa (without molasses) is a useful protein source for underweight horses. It provides highly digestible protein and sits lower in non-structural carbohydrates than most commercial feeds.

3. Feeding the horse with PPID and insulin dysregulation

When PPID comes with insulin dysregulation, the laminitis risk is not theoretical. Sustained hyperinsulinaemia alone is enough to trigger laminitis in clinically normal ponies [3]. This shifts the dietary goal from "lower sugar" to strict, measured NSC management.

• Have an oral sugar test or insulin tolerance test performed by your veterinarian every 4–6 months.
• Keep non-structural carbohydrates (NSC) below 10–12% of dry matter in the total ration [4].
• Analyse your roughage. Hay varies widely in sugar content depending on species, cutting time, and weather. Never assume it is safe without testing.
• Soak hay for 6 hours in cold water or 1–3 hours in warm water to reduce water-soluble carbohydrates by 20–40%.
• Exercise improves insulin sensitivity. For horses with active laminitis, this only happens in consultation with your vet.
• Oil provides energy without contributing to glycaemic load. EPA and DHA from marine algae oil also reduce adipose tissue inflammation, which directly worsens insulin sensitivity in PPID horses [2]. Grow & Glow from Curafyt supplies EPA and DHA from high-quality microalgae oil.

4. Feeding based on age and dental condition

PPID is predominantly a disease of older horses [1], and older horses bring their own feeding complications that exist independently of the hormonal picture. Dental wear, reduced mobility, and slower gut transit all change what the horse can process. It is worth checking teeth before assuming any weight change is PPID-related, because a horse that cannot chew properly will lose condition no matter what goes in the bucket.

• No dental problems: long-stem roughage remains ideal, it supports gut motility and natural grazing behaviour.
• Mild dental wear: chopped hay or hay pellets, soaked if needed.
• Severe dental problems: soaked beet pulp (without molasses) or soaked hay pellets as the primary roughage replacement.
• Feed at least 1.5% of body weight in dry matter per day.
• Several small meals, never more than 6 hours without roughage.
• Low-sugar feed choices reduce the risk of gastric ulcers.

Specific nutrients that matter in PPID

Beyond energy and roughage, a few micronutrients deserve specific attention.

• Amino acids: dopamine is synthesised from tyrosine, which depends on phenylalanine as a precursor. The dopaminergic deficit in PPID raises dietary demand for these. Lysine and threonine at 15–20 g/day support muscle development and help limit cortisol-driven breakdown [2].
• Vitamins and minerals: no specific guidelines exist for PPID beyond general equine recommendations. Adjust according to age, activity, and roughage quality with your vet.
• Electrolytes: PPID horses commonly drink and urinate more than normal, losing electrolytes through urine. A salt block should always be available.
• Vitamin C: supports immune function and lung health in horses with compromised immune status.

Conclusion

Managing a PPID horse through nutrition is not a one-time fix. Body condition, insulin levels, dental health, and age all shift over time, and the ration needs to shift with them. The constants: low sugar and starch, enough quality protein to counter muscle breakdown, and regular monitoring to catch changes before they become crises.

Get those things right and medication does not have to carry the full weight of managing the condition. A horse with PPID, fed and monitored consistently, can stay comfortable and functional for years.