Why Hay Is Essential for Guinea Pigs
Hay is the cornerstone of a guinea pig's diet. It provides necessary fiber for digestive health, helps wear down continuously growing teeth, and prevents obesity and gastrointestinal issues. Timothy hay, orchard grass, and meadow hay are excellent choices. Alfalfa hay is too high in calcium and protein for adult guinea pigs but suitable for pregnant or nursing sows and young pups under 6 months.
Recommended Diet Types
A balanced guinea pig diet consists of three main components: unlimited grass hay, a small portion of high-quality pellets, and fresh vegetables. Hay should be available 24/7 and make up about 80% of the diet. Pellets should be plain, timothy-based, and free of seeds, nuts, or dried fruit. Vegetables provide vitamin C, which guinea pigs cannot synthesize. Avoid commercial treats with added sugars or grains.
Hay Types and Benefits
- Timothy hay: Best for adults, low calcium and protein.
- Orchard grass: Similar to timothy, softer texture.
- Meadow hay: Variety of grasses, good for enrichment.
- Oat hay: Higher in fiber, suitable in small amounts.
- Alfalfa hay: For young, pregnant, or underweight guinea pigs only.
Portion Sizes and Daily Caloric Needs
Guinea pigs require approximately 50-60 calories per kg of body weight per day. An adult guinea pig (0.9-1.2 kg) needs about 45-70 calories daily. Hay provides few calories, so the main energy source is pellets and vegetables. Below is a general guide.
| Life Stage | Hay (unlimited) | Pellets (per day) | Vegetables (per day) | Calories (approx.) |
|---|---|---|---|---|
| Young (under 6 mo) | Alfalfa + grass hay | 1/8 cup | 1/4 cup | 40-60 |
| Adult (6 mo - 5 yrs) | Grass hay only | 1/8 cup | 1 cup | 50-70 |
| Senior (over 5 yrs) | Grass hay | 1/8 cup or less | 1 cup | 40-60 |
Adjust portions based on activity level. Sedentary or overweight pigs need fewer pellets; active pigs may need slightly more vegetables.
Feeding Frequency and Schedule
Hay should be available at all times. Pellets are typically given once daily. Vegetables should be offered twice daily in the morning and evening. Remove uneaten fresh food after a few hours to prevent spoilage. Fresh water must always be available, preferably from a water bottle changed daily.
Essential Nutrients
Guinea pigs have specific nutritional requirements:
- Fiber: 15-20% of diet (from hay).
- Protein: 12-18% for growth; 14-16% for maintenance.
- Fat: 2-4% (low-fat diet).
- Vitamin C: 10-30 mg per kg body weight daily. Must be provided through vegetables (bell peppers, kale, parsley) or supplements.
- Calcium: 0.6-1.2% for adults; higher for young and lactating. Over-supplementation causes bladder stones.
- Phosphorus: Balanced with calcium.
Safe Vegetables for Vitamin C
- Bell peppers (red, yellow, green)
- Kale
- Parsley
- Cilantro
- Romaine lettuce
- Broccoli leaves
Toxic and Harmful Foods
Avoid these foods entirely:
- Chocolate, candy, or any human junk food.
- Avocado (toxic).
- Onions, garlic, leeks, chives.
- Potatoes and potato skins.
- Rhubarb.
- Dairy products.
- Meat or animal products.
- Seeds, nuts, grains (except oats in small amounts).
- Iceberg lettuce (low nutrients, can cause diarrhea).
- Sugary fruits like grapes, bananas (feed sparingly, 1-2 times a week).
Water Intake
Guinea pigs drink about 50-100 ml per kg body weight daily. A healthy adult drinks 100-200 ml per day. Use a water bottle with a sipper tube, cleaned weekly. Ensure fresh water daily, especially in warm weather.
Nutritional Supplements
Vitamin C is the most important supplement. Provide 30-50 mg per day for adults. Use liquid vitamin C in water (made for guinea pigs) or chewable tablets. Avoid adding to water as it degrades quickly. Other supplements are usually unnecessary if diet is balanced. Oxbow Natural Science Vitamin C tablets are a popular choice.
Beneficial Supplements
- Probiotics (after antibiotic treatment or diarrhea).
- Digestive enzymes (for senior or ill pigs).
- Omega-3 fatty acids (small amount of flaxseed oil).
Age-Specific Feeding Differences
Young Guinea Pigs (under 6 months)
Feed alfalfa hay for extra calcium and protein. Pellets should be alfalfa-based for growth. Introduce vegetables gradually at 3-4 weeks. Ensure mother's milk if nursing.
Adult Guinea Pigs (6 months to 5 years)
Transition to grass hay only. Limit pellets to 1/8 cup daily. Provide a variety of vegetables for Vitamin C. Avoid overfeeding calcium-rich vegetables like spinach or kale in large amounts.
Senior Guinea Pigs (over 5 years)
May require softer hay if dental issues exist. Monitor weight; reduce pellets if overweight. Increase vegetables to maintain hydration. Consider adding a Vitamin C supplement. Watch for signs of arthritis or dental disease.
Signs of a Healthy vs. Poor Diet
Healthy Diet Indicators
- Bright, alert eyes and nose.
- Shiny, smooth coat.
- Consistent, well-formed droppings (oval, firm).
- Regular appetite and drinking.
- Normal weight (no sudden loss or gain).
- Active and playful behavior.
Poor Diet Indicators
- Lethargy or weakness.
- Diarrhea or soft stools.
- Dull, patchy fur or hair loss.
- Overgrown teeth or drooling.
- Weight loss or obesity.
- Urinary tract issues (blood in urine, straining).
- Eye discharge or skin problems.
If any signs appear, consult a veterinarian experienced with guinea pigs. Adjust diet gradually and avoid abrupt changes.