📋 At a Glance
⚠️ Senior Horse Signs Requiring Veterinary Evaluation
- Long, curly, or wavy coat that fails to shed normally in spring — classic PPID/Cushing's sign at any age over 10
- Significant weight loss despite adequate feed access — PPID, dental disease, malabsorption, or systemic illness
- Progressive muscle wasting along the topline with loss of normal back muscling
- Recurrent or unexplained laminitis in an older horse — strongly associated with PPID and EMS
- Dramatically increased water consumption and urination
- Sudden deterioration in performance or attitude in a previously well horse
- Difficulty chewing, quidding hay, or long-stem hay visible in manure
PPID (Cushing's Disease) — The Most Important Senior Horse Diagnosis
Pituitary Pars Intermedia Dysfunction (PPID) is the most common endocrine disorder in horses over 15, affecting more than 20% of that age group. It is also the most underdiagnosed — because early PPID produces subtle signs easily attributed to normal aging, while diagnosis requires a blood test that many horses never receive.
PPID is caused by progressive dopaminergic neuron loss in the hypothalamus, allowing the pars intermedia of the pituitary gland to enlarge and overproduce POMC-derived peptides including ACTH. Elevated ACTH drives cortisol excess, insulin dysregulation, immune suppression, and muscle catabolism. The consequences — laminitis, infections, muscle wasting, dental disease acceleration — are all dramatically better managed when PPID is identified and treated early with pergolide (Prascend).
| PPID Sign | Early | Moderate | Advanced |
|---|---|---|---|
| Coat | Slightly delayed spring shed; subtle texture change | Coat fails to shed in spring; longer than normal | Classic hypertrichosis — long, curly, wavy coat year-round |
| Muscle | Subtle topline loss | Progressive muscle wasting; hollow topline | Severe muscle atrophy; pot belly from abdominal muscle loss; prominent spine |
| Laminitis | None (but insulin dysregulation present) | Episodic laminitis especially during grass season | Recurrent laminitis; founder episodes |
| Water/urination | Mild increase | Noticeably increased — frequently wetting stall | Polydipsia/polyuria significantly affecting stall management |
| Infections | None or subclinical | Increased susceptibility to skin, dental, respiratory infections | Recurrent infections; poor wound healing |
| Fat deposits | Subtle | Supraorbital fat pads above eyes; cresty neck | Marked regional fat redistribution; pendulous abdomen |
ACTH Testing — What to Know
- Test involves a single blood draw from the jugular vein — typically takes 2–5 minutes
- Seasonal reference ranges apply: ACTH rises physiologically August–October; fall testing requires seasonal adjustment
- Best spring testing window for clearest baseline results: February through July
- If signs are present in fall, test anyway and apply seasonal reference ranges — a horse that needs treatment should not wait until spring
- Borderline results: TRH stimulation test is more sensitive and can identify earlier PPID
- Diagnosed horses: retest 4–6 weeks after starting pergolide, then annually; dose often needs adjustment over time as disease progresses
Dental Health in the Senior Horse
The equine cheek tooth is a hypsodont structure with approximately 5–6 inches of reserve crown at birth, which gradually erupts to compensate for wear over the horse's lifetime. By the late teens to mid-twenties, the reserve crown is significantly depleted. Occlusal surfaces become irregular (wave mouth, step mouth), tooth roots are exposed and vulnerable, and teeth may loosen or fall out. Simultaneously, the chewing efficiency required to process conventional hay declines.
For senior horses, biannual dental exams (every 6 months rather than annually) are increasingly the standard of care. The goals at each exam shift from simple floating to progressive assessment of dental function, monitoring for diastema (gaps between teeth that trap food and cause periodontal disease), managing loose teeth, and — most importantly — advising on dietary modification appropriate to current dental function.
| Dental Sign | Significance | Dietary Implication |
|---|---|---|
| Quidding (dropping feed) | Inadequate chewing due to pain or dental wear | Consider hay cubes (soaked), hay pellets, or complete senior feed |
| Long stems in manure | Hay not being chewed adequately | Transition toward softer/soaked feed formats |
| Weight loss despite hay access | Caloric intake insufficient due to inadequate chewing | Soaked/steamed hay; complete senior feeds; dental exam urgently |
| Wave mouth | Uneven occlusal surface limiting grinding efficiency | May need more frequent floating; diet modification |
| Diastema (tooth gaps) | Food packing → periodontal disease → pain | Dietary management; some respond to gap widening; veterinary management |
| EOTRH (incisor resorption) | Painful progressive disease; incisors first | Radiographic diagnosis; affected incisors may need extraction |
Nutrition for the Senior Horse
The nutritional challenges of the senior horse arise from three main sources: reduced chewing efficiency limiting hay processing, reduced digestive efficiency requiring more calories to maintain the same body weight, and the metabolic changes associated with PPID and EMS that require specific dietary management.
For horses with adequate dental function, a high-quality forage-based diet remains appropriate — but body condition should be monitored monthly. For horses with compromised dental function, soaked hay cubes, steamed hay, hay pellets, or complete senior feeds provide adequate calories in a form the horse can process. Many senior horses need significantly more calories than younger horses to maintain the same body condition — the starting point for addressing weight loss is always increasing caloric input while verifying that the form of feed can actually be chewed and digested.
Feeding the Dentally Compromised Senior
- Soaked hay cubes: break up and soak in water until soft (15–30 minutes minimum); horses with significant dental loss can eat these when conventional hay is impossible
- Complete senior feeds: formulated to replace hay entirely; fed in sufficient quantity to meet all nutritional needs including fiber
- Steamed hay: maintains nutritional value better than soaking while reducing dust and softening the stems
- Beet pulp (soaked): highly digestible fiber source; excellent for adding calories without starch; always soak thoroughly
- Probiotic/prebiotic supplementation: hindgut efficiency may decline with age; discuss with vet
Joint Management in Senior Horses
Some degree of osteoarthritis is nearly universal in horses that have been in work through their teens and beyond. The goal of management is not to cure arthritis — which is not reversible — but to maintain adequate comfort for the horse's intended use and quality of life. A wide range of evidence-based management options exist.
Joint Management Options (Discuss with Your Vet)
- NSAIDs (phenylbutazone, meloxicam, flunixin): effective for acute pain management; long-term use carries gastric and renal risks — use the lowest effective dose
- Joint injections (corticosteroids, hyaluronic acid, PRP, IRAP): for specific affected joints; corticosteroids provide reliable anti-inflammatory effect; biologics (PRP, IRAP) growing in evidence base
- Bisphosphonates (tiludronate, clodronate): modulate bone remodeling; appropriate for navicular and hock bone pathology; IV or regional perfusion
- Controlled exercise: appropriate low-impact movement maintains joint fluid circulation and muscle support; stall rest worsens OA in most cases
- Supportive shoeing: appropriate hoof balance and breakover modification reduces joint loading asymmetry
- Weight management: every pound of excess body weight increases joint loading; appropriate body condition is therapeutic
Quality of Life Assessment — Planning for the Future
One of the most important conversations horse owners can have with their veterinarian is a quality of life assessment — and the best time to have it is when the horse is still relatively well, not in the middle of a crisis. Establishing clear criteria for what constitutes acceptable quality of life, what signs would indicate significant suffering, and what the owner's goals are for end-of-life care produces far better decision-making when the time comes.
Simple quality of life frameworks for horses consider: the horse's ability to eat and drink normally, the horse's mobility and ability to rise and lie down without assistance, the presence and controllability of pain, the horse's social engagement and apparent interest in surroundings, and the frequency and severity of bad days vs. good days.
✅ Senior Horse Annual Health Program
- Schedule biannual veterinary exams — twice yearly assessment is the standard of care for horses over 15
- Annual ACTH testing — ideally spring (February–July) for clearest baseline; fall if signs are present
- Dental exam every 6 months — and immediately adjust the diet to match current chewing function
- Monthly body condition scoring — compare to prior months; early weight loss is far easier to address than advanced cachexia
- Discuss joint management with your vet — many evidence-based options; tailor to which joints are affected and the horse's use
- Quality of life conversation — before a crisis, establish criteria for intervention and end-of-life care
📋 Senior Health Discussion Points for Your Vet
- ACTH result interpretation — seasonal adjustment if testing August–October; pergolide starting dose if PPID confirmed
- Dental status and appropriate feed format — what can this horse actually chew and digest right now?
- Insulin measurement alongside ACTH — elevated insulin dramatically increases laminitis risk in PPID horses
- Joint injection schedule — which joints, what products, how often
- Vaccination protocol review — aging immune systems may benefit from different timing or products
- Parasite management — immunosenescence may reduce natural resistance; more aggressive monitoring warranted
Questions to Ask Your Veterinarian
- What is this horse's ACTH level and does it fall within the seasonal reference range for this time of year?
- Should we test resting insulin alongside ACTH to assess concurrent EMS and laminitis risk?
- Based on today's dental exam, what feed format is appropriate for this horse's current chewing function?
- Which joints are contributing most to this horse's discomfort, and what injection schedule do you recommend?
- At what point should I shift from the current management program to a more intensive comfort-focused approach?
- What quality of life indicators should prompt me to call you for a reassessment between scheduled visits?
