Guinea Pig Diet Essentials (Vitamin C, Hay & Safe Vegetables)

Guinea pigs have unique dietary needs that differ significantly from other small pets. Understanding their nutritional requirements, especially their critical need for vitamin C, is essential for maintaining their health and preventing serious diseases like scurvy.

The Foundation: Unlimited Timothy Hay

Why Hay is Critical

Hay should make up 75-80% of your guinea pig’s diet and provides:

• Essential fiber for proper digestion
• Dental wear (guinea pig teeth grow continuously)
• Mental stimulation and natural foraging behavior
• Prevention of gastrointestinal stasis

Types of Hay

Timothy Hay (Best for Adults 6+ months):

• Lower calcium content prevents urinary stones
• Higher fiber promotes healthy digestion
• Available in multiple cuts (1st cut = coarser, 3rd cut = softer)
• Should be green, fragrant, and dust-free

Alfalfa Hay (Young Guinea Pigs Only):

• Higher protein and calcium for growth
• Suitable for pregnant/nursing females
• Too rich for adult guinea pigs
• Can cause urinary sludge in adults

Other Acceptable Hays:

• Orchard grass (good for picky eaters)
• Meadow hay
• Oat hay (as variety, not main hay)

Hay Quality Signs

✅ Good hay:

• Green color (not brown or yellow)
• Sweet, fresh smell
• Minimal dust
• Soft texture
• No signs of mold

High-Quality Pellets

Pellet Guidelines

• Amount: 1/8 cup per pound of body weight daily
• Type: Timothy-based pellets with vitamin C
• Vitamin C content: At least 30mg per serving
• Age considerations: Young guinea pigs need more pellets

What to Look For in Pellets

Quality indicators:

• Timothy hay as first ingredient
• 20-25% crude fiber minimum
• 14-20% protein for adults
• Stabilized vitamin C added
• No seeds, nuts, or colored pieces

Avoid pellets with:

• Alfalfa as main ingredient (for adults)
• Seeds, nuts, or dried fruits mixed in
• Artificial colors or preservatives
• Generic “rabbit food” (different nutritional needs)

Vitamin C: The Critical Nutrient

Why Guinea Pigs Need Vitamin C

Guinea pigs, like humans, cannot produce vitamin C internally and must obtain it from their diet. Deficiency leads to scurvy, a serious and potentially fatal condition.

Daily Vitamin C Requirements

• Adults: 30mg daily
• Pregnant females: 60mg daily
• Growing guinea pigs: 50mg daily
• Sick guinea pigs: Up to 100mg daily (with vet guidance)

Best Sources of Vitamin C

Vegetables (mg per 100g):

• Red bell pepper: 190mg
• Yellow bell pepper: 183mg
• Green bell pepper: 120mg
• Kale: 120mg
• Broccoli: 89mg
• Strawberries: 59mg
• Cilantro: 27mg

Daily Serving Examples:

• 1/4 cup bell pepper strips = ~50mg vitamin C
• 2-3 large strawberries = ~20mg vitamin C
• 1/4 cup chopped kale = ~30mg vitamin C

Fresh Vegetables (1 cup per pound daily)

Vitamin C Rich Vegetables (Daily)

High vitamin C (primary choices):

• Bell peppers (all colors)
• Leafy greens (kale, romaine, cilantro)
• Broccoli (small amounts)
• Tomatoes (occasionally)

Safe Daily Vegetables

Dark leafy greens:

• Romaine lettuce
• Red or green leaf lettuce
• Cilantro
• Parsley
• Dill
• Mint

Other safe vegetables:

• Cucumber
• Carrot (small amounts - high sugar)
• Celery
• Zucchini
• Green beans

Vegetables to Limit

High calcium (2-3 times per week only):

• Kale
• Spinach
• Collard greens
• Dandelion greens

High sugar (treats only):

• Carrots
• Sweet peppers
• Fruit

Vegetables to Avoid Completely

❌ Never feed:

• Iceberg lettuce (no nutrition, causes diarrhea)
• Onions and garlic
• Mushrooms
• Avocado
• Potato and potato leaves
• Rhubarb
• Chocolate (toxic)

Fruits (Limited Treats)

Safe Fruits (2-3 times per week, small portions)

• Strawberries (high vitamin C)
• Orange segments (small amounts)
• Apple (remove seeds)
• Pear
• Melon
• Grapes (cut in half)

Fruit Guidelines

• Portion size: 1-2 small pieces
• Frequency: 2-3 times per week maximum
• Remove: Uneaten fruit after 2 hours
• Avoid: Dried fruits (too concentrated)

Water Requirements

Fresh Water Daily

• Amount: 100-300ml per day per guinea pig
• Container: Heavy ceramic bowl or water bottle
• Quality: Fresh, clean water
• Temperature: Room temperature

Important Water Notes

• Change water daily
• Clean containers regularly
• Monitor consumption (changes may indicate illness)
• Never add vitamins to water (promotes bacterial growth)

Feeding Schedule & Routine

Daily Feeding Schedule

Morning:

• Fresh hay refill
• Daily pellet portion
• 1/2 cup vegetables

Evening:

• Check hay levels
• 1/2 cup vegetables
• Small fruit treat (if offering)

Continuous:

• Hay available 24/7
• Fresh water always available

Portion Guidelines for 2-pound Guinea Pig

• Hay: Unlimited
• Pellets: 1/4 cup daily
• Vegetables: 1 cup daily total
• Fruit: 1-2 small pieces, 2-3 times per week

Special Dietary Considerations

Baby Guinea Pigs (Under 6 months)

• Unlimited alfalfa pellets
• Can have alfalfa hay
• Same vegetables as adults
• More frequent feeding (3-4 times daily)

Pregnant/Nursing Females

• Unlimited high-quality pellets
• Can have alfalfa hay
• Extra vitamin C (60mg daily)
• Free-choice feeding during nursing

Senior Guinea Pigs (5+ years)

• May need softer foods
• Regular weight monitoring
• Potential pellet increase if losing weight
• Continue vitamin C supplementation

Overweight Guinea Pigs

• Reduce pellets to 1/8 cup per 2 pounds
• Increase exercise opportunities
• Focus on lower-calorie vegetables
• Consult veterinarian for diet plan

Vitamin C Supplementation

When to Supplement

• If diet lacks vitamin C-rich vegetables
• During illness or stress
• For picky eaters
• As insurance against deficiency

Supplementation Methods

Vitamin C tablets:

• Crush and sprinkle on vegetables
• 25-30mg daily for adults
• Choose plain ascorbic acid

Liquid vitamin C:

• Add to vegetables, not water
• Follow package directions
• Refrigerate after opening

Signs of Vitamin C Deficiency (Scurvy)

🚨 Emergency symptoms:

• Swollen, painful joints
• Dental problems
• Poor wound healing
• Lethargy and weakness
• Rough, dull coat
• Loss of appetite

Common Diet Mistakes

Feeding Errors to Avoid

1. Not enough hay: Leads to dental and digestive problems
2. Too many pellets: Causes selective eating and obesity
3. Insufficient vitamin C: Results in scurvy
4. Wrong pellet type: Rabbit pellets lack necessary nutrients
5. Too much fruit: Causes diarrhea and obesity
6. Sudden diet changes: Can cause digestive upset

Transitioning Foods

When introducing new vegetables:

1. Start with tiny amounts
2. Introduce one new food at a time
3. Watch for soft stools or diarrhea
4. Wait 3-5 days before adding another new food
5. Remove any food that causes digestive upset

Monitoring Your Guinea Pig’s Health

Signs of Good Nutrition

✅ Healthy indicators:

• Regular appetite
• Normal droppings production
• Steady weight
• Bright, alert behavior
• Healthy coat
• Active movement

Warning Signs

🚨 Call vet immediately if:

• No eating for 12+ hours
• No droppings for 12+ hours
• Diarrhea or very soft stools
• Significant weight loss
• Lethargy or hiding
• Swollen joints (scurvy symptoms)

Related Herbivore Diet Guides

If you’re interested in other herbivorous small pets with similar dietary needs:

• Rabbit Diet Basics - Similar hay-based nutrition with different pellet requirements
• Rabbit Care Guide - Complete care information for another popular herbivore

Both guinea pigs and rabbits require unlimited hay and careful attention to their digestive health, making them similar in many dietary aspects.

Remember: Proper nutrition is the foundation of guinea pig health. A diet rich in hay, fortified with vitamin C, and supplemented with fresh vegetables will keep your guinea pig healthy and happy for their 4-8 year lifespan.