How to Tell If a Guinea Pig Is Sick

Introduction

Guinea pigs are prey animals that instinctively hide signs of illness. By the time a guinea pig appears obviously sick, they may already be in serious trouble. Knowing how to tell if a guinea pig is sick — and acting quickly — can save your guinea pig's life. Here's what to watch for.

Know Your Guinea Pig's Normal Baseline

The best way to detect illness early is to know what's normal for your individual guinea pig. Observe daily and track:

• Weight — Weigh weekly with a kitchen scale. A loss of 50g or more in a week warrants a vet visit.
• Appetite — Guinea pigs should eat hay enthusiastically throughout the day
• Droppings — Should be uniform, firm, and oval-shaped; produced consistently
• Vocalizations — Know your guinea pig's normal sounds
• Activity level — Alert and active during morning and evening hours

Warning Signs of Illness

Digestive System

• Not eating hay — Always serious; act within hours
• Reduced or absent droppings — Indicates digestive slowdown
• Diarrhea or very soft droppings — Can indicate infection or dietary issues
• Bloated or hard belly — Dangerous gas buildup; emergency
• Weight loss — Even gradual loss is significant in a small animal

Respiratory System

• Sneezing frequently — Can indicate respiratory infection ("snuffles")
• Nasal discharge — White or yellow discharge indicates infection
• Labored or rapid breathing — Serious; seek vet care promptly
• Clicking or wheezing sounds — Respiratory infection or pneumonia

Behavioral Changes

• Lethargy — A guinea pig that doesn't respond to food or interaction is unwell
• Hunched posture — Indicates pain or discomfort
• Tooth grinding — Pain response
• Hiding more than usual — Sick guinea pigs retreat
• Loss of interest in food, especially favorites — Always a red flag

Physical Signs

• Crusty or watery eyes — Infection or dental problems
• Hair loss or bald patches — Fungal infection (ringworm) or mites
• Scratching excessively — Mites or fungal infection
• Swollen joints or limbs — Injury or arthritis
• Lumps or bumps — Abscesses or tumors
• Wet or soiled bottom — Diarrhea or urinary issues

Vitamin C Deficiency (Scurvy)

Guinea pigs cannot produce their own vitamin C. Signs of deficiency include:

• Rough, dull coat
• Swollen or painful joints
• Reluctance to move
• Slow wound healing
• Dental problems

Prevent scurvy with daily bell pepper, leafy greens, and Oxbow Natural Science Vitamin C Supplement.

Emergency Signs — Act Immediately

• Not eating for 4+ hours
• No droppings for 4+ hours
• Labored or open-mouth breathing
• Seizures or collapse
• Extreme lethargy — cannot be roused
• Temperature below 99°F (check with a pet thermometer)

Monitoring Tools

Keep a kitchen scale for weekly weigh-ins, a digital pet thermometer, and oral syringes for emergency syringe feeding under vet guidance. Find a rabbit-savvy exotic vet who also treats guinea pigs before you need one.

Conclusion

Daily observation and weekly weigh-ins are your most powerful tools for catching guinea pig illness early. When something seems off — especially changes in eating, droppings, or activity — act quickly. Guinea pigs can decline rapidly, but they can also recover well with prompt veterinary treatment.