Things you should never feed your horse

Horses are herbivores with highly sensitive digestive systems, so knowing exactly what they can and can’t eat is essential for their health.

• Processed foods
• Dairy
• Fruit
• Vegetables
• Plants
• Treats

Why your horse’s diet matters

Your horse’s stomach contains good bacteria designed to break down their usual diet. Sudden changes can upset this balance and increase the risk of colic.

Constant access to fresh, clean water is essential, and equines need plenty of fibre from forage. So, hay should always form the foundation of their diet.

What horses should NOT eat (by food group)

Processed foods and human treats

• Processed foods (e.g. crisps, biscuits, pot noodles)
• Sweets
• Chocolate – contains theobromine, which can cause colic and seizures
• Bread – can form a blockage in the digestive system, leading to colic

Dairy products

Horses are lactose intolerant. Even small amounts of dairy can cause diarrhoea, while larger amounts may lead to colic.

Meat and animal products

• Meat of any kind
• Meat by-products (e.g. gelatine)

These are not digestible for horses and should never be fed to them.

Garden waste and poor-quality feed

• Grass clippings (ferment quickly and can cause colic)
• Garden cuttings (may contain toxic plants)
• Mouldy hay or haylage
• Expired or dusty feed

Always check feed quality. If it smells unpleasant or looks mouldy, don’t use it.

Toxic plants and high-risk foods

Nightshade family

• Tomatoes (plant and fruit can affect digestion and heart rate)
• Potatoes (toxic whether raw or cooked)

Allium family

• Onions
• Leeks
• Shallots
• Chives

These damage red blood cells and can cause anaemia.

Cruciferous vegetables (feed with caution or avoid)

• Cabbage
• Broccoli
• Cauliflower
• Brussels sprouts

These contain raffinose, which can cause gas and increase the risk of colic.

Other harmful foods

• Avocado (can affect heart and breathing)
• Rhubarb (linked to kidney failure)
• Caffeine (can affect heart rate and competition eligibility)

Fruits and vegetables: what’s safe vs unsafe

Safe fruits (in small amounts)

Horses can enjoy small amounts of fruit as treats:

• Apples (without the core)
• Bananas
• Watermelon
• Strawberries
• Grapes – safe in small quantities, but should always be cut in half to reduce choking risk

Safe vegetables (in moderation)

• Carrots (cut lengthways)
• Celery
• Cucumber
• Lettuce
• Parsnips – can be fed occasionally as a treat due to their sugar content

All vegetables should be chopped into manageable pieces to prevent choking.

Vegetables to avoid or limit

• Tomatoes (toxic plant family)
• Potatoes (toxic)
• Cabbage, broccoli, cauliflower, sprouts (gas-producing)

Plants and foraging risks

Many plants are highly toxic to horses and should be removed from grazing areas, including:

• Ragwor
• Foxglove
• Ivy
• Yew
• Sycamore
• Buttercups
• Hemlock

If you suspect your horse has eaten a poisonous plant, contact your vet immediately.

Safe treats for horses

Horses can enjoy treats in moderation, including:

• Carrots
• Apples (no core)
• Bananas
• Watermelon
• Strawberries

Can horses eat mints?

Peppermints are generally considered safe in very small amounts, but:

• Avoid chewy mints or gum
• Ensure they don’t contain animal by-products
• Treat as an occasional reward, not a regular snack

Healthy feeding schedules for horses

A consistent feeding routine is just as important as the food itself. Horses have evolved to graze little and often, so their diet should reflect this natural behaviour.

Best practice feeding routine:

• Provide constant access to forage (hay or grass)
• Feed small, frequent meals instead of large portions
• Introduce dietary changes gradually over 7–14 days
• Avoid long periods without food, which can increase ulcer risk

Feeding at the same time each day can also help reduce stress and support digestive health.

How to keep your horse at a healthy weight

Maintaining a healthy weight is key to preventing issues like laminitis, joint strain, and metabolic disorders. 

Signs your horse is a healthy weight:

• Ribs can be felt but not seen clearly
• No excessive fat around the neck or tail head
• A balanced, smooth body shape

Tips to manage weight:

• Monitor body condition regularly
• Adjust feed based on workload and season
• Limit high-sugar treats (including fruit like apples and parsnips
• Encourage regular exercise

If you’re unsure about your horse’s weight, your vet can help assess their body condition score and recommend dietary changes.

Understanding what your horse can and can’t eat is essential for preventing serious health issues like colic. When in doubt, stick to a forage-based diet and introduce any new foods slowly.

If you think your horse has eaten something toxic, contact your vet immediately.

Related articles:

• What to feed your horse
• Poisonous plants for horses
• Managing your horse’s weight