Faktengeprüft & evidenzbasiert Tierärztlich geprüft

Dürfen Pferde Spinat fressen?

Verfasst von

Dra. Carmen Ortega

Veterinär-Ernährungsspezialistin

Medizinisch geprüft von

Dr. Sarah J. Whitaker

Leitende Veterinärtoxikologin

Aktualisiert Jun 2026

Mit Vorsicht füttern

Feed Spinach to Horses With Caution — Occasional Tiny Amounts Only

Spinach belongs to the high-oxalate family of plants. In horses, dietary oxalates bind free calcium in the gut, preventing its absorption and — over time — potentially leading to nutritional secondary hyperparathyroidism (a condition well-documented in horses grazing oxalate-rich tropical grasses). A one-off nibble is highly unlikely to harm a mature, healthy horse, but there is no good reason to include spinach as a regular dietary item. Owners looking for healthy vegetable treats have far better, lower-risk options.

Schweregrad

Low

Toxische Dosis

No established single toxic dose; chronic feeding of >1–2 kg oxalate-rich greens per day is associated with calcium disruption; even moderate habitual amounts (several handfuls daily) warrant concern over weeks

Einsetzzeit

Acute GI upset within 1–4 hours (large amounts); chronic oxalate effects develop over weeks to months of regular feeding

Behandlung

Discontinue spinach; ensure adequate dietary calcium from hay and balanced feed; veterinary assessment if signs persist or if kidney disease is suspected

Verantwortungsvoll füttern

Maß halten ist entscheidend

Spinat sollte pferde nur in kleinen, seltenen Mengen angeboten werden. Befolgen Sie die Hinweise zur sicheren Fütterung und beobachten Sie genau auf etwaige Reaktionen.

Sichere Fütterungstipps ansehen Einen Tierarzt fragen

Why Is Spinach a Concern for Horses?

Spinat — pferde.

Spinach (Spinacia oleracea) contains one of the highest oxalate concentrations among common leafy vegetables — roughly 600–750 mg of oxalic acid per 100 g fresh weight. In the equine digestive tract, soluble oxalates readily bind dietary calcium and magnesium to form insoluble calcium oxalate crystals. These crystals are not absorbed; instead, they pass through or accumulate, reducing the horse's net calcium uptake. Horses are uniquely sensitive to oxalate-induced hypocalcemia compared with many other species because of their relatively slow hindgut fermentation and dependence on continuous forage calcium.

The primary concern with habitual spinach feeding is nutritional secondary hyperparathyroidism — colloquially called 'big head disease' or 'millers' disease' in horses — a well-recognised syndrome in animals consuming high-oxalate diets over months. The parathyroid gland compensates for low blood calcium by mobilising calcium from bones, leading to facial bone swelling, lameness, and skeletal weakness. Additionally, calcium oxalate crystals can contribute to enterolith formation in horses predisposed to colonic stone accumulation. A single small treat is a very different exposure from weekly or daily feeding, and the risk scales accordingly.

The Oxalate Problem in Plain Terms

Think of oxalates as calcium 'blockers' — each gram of oxalic acid in spinach ties up roughly 0.9 g of dietary calcium before it can reach your horse's bloodstream. Forages like grass hay are already a borderline calcium source for working horses, so adding a high-oxalate food repeatedly stacks the deficit.

Symptome & Verlauf

Acute GI Signs (Large Single Feeding)

Loose manure or diarrhoea
Mild colic (pawing, flank-watching)
Reduced appetite
Excessive salivation

Alle Lebensmittel ansehen, die diese Symptome verursachen

Chronic Oxalate Toxicity (Regular Feeding Over Weeks–Months)

Facial bone swelling ('big head')
Shifting-leg lameness
Muscle tremors or stiffness
Poor hoof quality
Weight loss

Alle Lebensmittel ansehen, die diese Symptome verursachen

Urinary / Renal Signs (Susceptible Individuals)

Altered urine colour (cloudy or pale)
Reduced urination
Flank pain consistent with kidney discomfort

Alle Lebensmittel ansehen, die diese Symptome verursachen

Dosis & Schweregrad

These portion estimates are for a healthy, mature horse (450–550 kg) with no pre-existing kidney or metabolic disease and a properly balanced forage-based diet. They represent maximum occasional treat quantities, not recommended daily amounts — spinach has no place in a horse's regular feed programme.

Single Incidental Nibble

1–3 leaves (≈10–30 g)

Negligible risk

Physiologically inconsequential in a healthy adult horse; no action needed

Small Occasional Treat

A small handful (≈50–100 g), once a week or less

Low risk — monitor

Unlikely to cause measurable calcium disruption; avoid in horses with kidney issues or calcium-deficient diets

Regular Supplemental Feeding

Several large handfuls (200–500 g) multiple times per week

Moderate concern

Cumulative oxalate load becomes clinically relevant; discontinue and review diet calcium balance

Daily or High-Volume Feeding

>500 g daily sustained over weeks

High risk of hypocalcemia

Consistent with oxalate-related bone and metabolic disease; veterinary assessment warranted

What to Do If Your Horse Has Been Eating Spinach

1
One-off nibble or accidental exposure: No emergency action is required. Monitor your horse for loose manure or mild colic over the next few hours. Ensure fresh water is freely available to support normal kidney filtration.
2
If you've been offering spinach regularly as a treat: Stop immediately and review your horse's total diet. Confirm that hay and concentrate rations are meeting calcium requirements (mature horses need roughly 20–30 g calcium per day depending on workload). A forage analysis and ration balancing consult with an equine nutritionist is worthwhile.
3
If you notice facial swelling, recurrent lameness, or muscle stiffness: Contact your veterinarian promptly. These signs may indicate nutritional secondary hyperparathyroidism. Blood calcium, phosphorus, and parathyroid hormone levels should be assessed. Radiographs of facial bones may be needed in advanced cases.
4
Horses with kidney disease or a history of enteroliths: Spinach should be completely avoided. Even small intermittent amounts carry disproportionate risk in these individuals. Discuss all treat choices with your vet.

Sichere Alternativen

Several vegetables and fruits offer genuine enrichment or nutritional benefit for horses without the oxalate risk associated with spinach.

Carrots

A classic, well-tolerated equine treat; rich in beta-carotene and naturally sweet, with a low oxalate content and a long safety record — feed sliced lengthwise to reduce choke risk

Apple (core and seeds removed)

Horses find apples highly palatable; modest natural sugars make them suitable as occasional treats for non-metabolic horses; avoid in horses with equine metabolic syndrome or laminitis history

Celery

Low in calories and oxalates, high in water content; a crunchy, hydrating snack that most horses enjoy without digestive concerns

Pumpkin (plain, no spices)

Soft flesh is easily digestible; provides fibre, beta-carotene, and some potassium; remove seeds and skin before offering

Timothy or Alfalfa Hay Cubes

The gold standard safe 'treat' for horses — no toxicity risk, supports dental wear, and directly supplements the calcium and fibre horses genuinely need

Häufig gestellte Fragen

My horse grabbed a mouthful of spinach from the garden — should I call the vet?

Almost certainly not, provided it was just a mouthful (roughly a handful or less) and your horse is otherwise healthy. A one-off incidental ingestion of 50–100 g of spinach will not deliver enough oxalic acid to cause meaningful calcium disruption in a 500 kg horse. Watch for soft manure or mild colic over the next 2–4 hours, offer plenty of fresh water, and carry on as normal. If your horse shows signs of colic that worsen or don't resolve within an hour, or if it's a foal or a horse with known kidney disease, contact your vet to be safe.

Are there any horses for whom even a small amount of spinach is genuinely dangerous?

Yes. Horses with existing chronic kidney disease are at heightened risk because oxalate crystals can accumulate in renal tubules when the kidneys are already compromised, potentially accelerating renal failure. Horses with documented hypocalcemia, nutritional secondary hyperparathyroidism, a history of enterolithiasis (calcium oxalate or calcium carbonate stones in the colon), or young, growing foals on borderline calcium diets should not receive spinach at all — not even as a one-off treat. If you're unsure about your horse's calcium status or kidney health, a routine blood panel from your equine vet will give you a clear picture.

I've read that leafy greens are healthy for horses — why is spinach different from, say, lettuce?

The key difference is oxalate concentration. Romaine or iceberg lettuce contains roughly 10–30 mg oxalic acid per 100 g — low enough that sensible treat-sized portions pose no real concern for horses. Spinach contains 600–750 mg per 100 g, making it roughly 20–30 times higher in oxalates than most lettuces. That gap is clinically significant when you consider how sensitive horses are to dietary oxalate loading. So the 'leafy greens are healthy' generalisation simply doesn't transfer from human nutrition to equine feeding for oxalate-rich species like spinach, Swiss chard, or beet greens.

Quellen & Referenzen

Merck Veterinary Manual: Oxalate Poisoning in Horses, Nutritional Secondary Hyperparathyroidism (Enzootic Calcinosis), Merck & Co., current online edition
ASPCA Animal Poison Control Center: Toxic and Non-Toxic Plant/Food Database — Oxalate-Containing Plants (aspca.org/pet-care/animal-poison-control)
McKenzie, R.A. (1981). 'Bovine enzootic haematuria and oxalate nephropathy in cattle and horses.' Australian Veterinary Journal, 57(10), 473–478
National Research Council (NRC). Nutrient Requirements of Horses, 6th revised edition. National Academies Press, Washington DC, 2007

Über die Autorin: Dra. Carmen Ortega

Veterinär-Ernährungsspezialistin

Diplomierte Veterinärernährungsexpertin mit Fokus auf artgerechte Diäten und präventive Fütterung, Hauptautorin unserer Ernährungsempfehlungen.

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