Guinea pig bladder stones cause painful urination, blood-tinged urine, and constant straining. They are very common — calcium-based stones form from a high-calcium diet plus low water intake. Surgery is usually needed because guinea pig stones do not dissolve medically. Diet changes after surgery reduce recurrence.
Last reviewed: May 2026
Symptoms of Bladder Stones
Guinea pigs with bladder stones typically squeak, vocalize, or hunch while urinating. Urine often contains visible blood (pink or red urine), though some stones cause only thick gritty discharge. Many affected pigs assume the urination posture frequently with little or no urine produced. Appetite drops, the pig hides, and weight loss follows. Calcium carbonate is the most common stone composition in guinea pigs, accounting for about 90 percent of cases (Hawkins et al., 2009, JAVMA). Around 8 to 10 percent of pet guinea pigs develop urolithiasis at some point (AEMV Pet Care Guides, 2024).
Why Guinea Pigs Get Stones
Guinea pigs absorb most dietary calcium passively rather than regulating it tightly. High-calcium diets (alfalfa hay or pellets in adults, generous amounts of high-calcium greens), low water intake, obesity, and chronic urinary tract inflammation all contribute. Some pigs have a genetic tendency. Older females have higher rates than males. Bladder stones cause pain and predispose to recurrent infection, as described in Quesenberry & Carpenter's Ferrets, Rabbits & Rodents.
Diagnosis and Treatment
Diagnosis is by abdominal palpation (a skilled vet can feel a large stone), urinalysis (showing crystals, blood, and sometimes infection), and radiographs, which detect almost all calcium-based stones. Ultrasound is added if a small stone or sludge is suspected. Treatment is surgical removal (cystotomy) under general anesthesia. Stones cannot be dissolved with diet alone, unlike some cat and dog stones. Surgery costs significantly more in guinea pigs because of the anesthesia risk and the need for an exotics surgeon. Antibiotics and pain medication are continued for 7 to 14 days post-operation.
Preventing Recurrence
Around 30 to 50 percent of guinea pigs that have one stone develop another within 1 to 2 years without diet change. Switch adult guinea pigs (over 6 months) to timothy or orchard grass hay and timothy-based pellets — never alfalfa as the main hay. Limit high-calcium greens like spinach, parsley, and kale to small portions. Offer unlimited fresh water in both a bowl and a bottle to maximize intake. Increase moisture with daily vegetables. Recheck radiographs every 6 to 12 months in prone animals.
When to See a Vet
Not every symptom is a midnight emergency, but some warrant same-day attention and a few are true ERs. Use the lists below to sort which bucket you're in.
Call your vet today if:
- Pink, red, or visibly bloody urine
- Squeaking or vocalizing while urinating
- Frequent posturing to urinate with little output
- Reduced appetite or weight loss
- Urine smell stronger or different than usual
Go to the ER immediately if:
- Complete inability to urinate for 4+ hours
- Severe pain — constant vocalizing, won't move, hunched
- Bloated belly with straining and crying
- Collapse or extreme weakness
- Refusal of all food and water for 6+ hours
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Frequently Asked Questions
Can guinea pig bladder stones pass on their own?
Very small stones occasionally pass spontaneously, but most are too large by the time signs appear. Surgical removal is the standard of care. Trying to wait causes prolonged pain and risk of urinary obstruction, which is a life-threatening emergency in guinea pigs.
How much does guinea pig bladder stone surgery cost?
Initial exotics-vet exam runs $80–200 and radiographs are $200–400. Pre-surgery bloodwork adds $150–300. Cystotomy surgery at an exotics specialty hospital ranges $1,500–3,500. Hospitalization for 1 to 3 days post-operation costs $400–800 per day. Pain medication and antibiotics for 2 weeks add $60–150. Total cost typically lands $2,000–4,500. Exotic vets charge about 1.5 to 2 times standard small-animal rates.
Will my guinea pig get more bladder stones?
Without dietary changes, about 30 to 50 percent of guinea pigs that have one stone develop another within 1 to 2 years. With aggressive prevention — timothy hay, limited high-calcium greens, increased water intake, weight control — recurrence drops to roughly 15 to 25 percent.
What greens are safe for stone-prone guinea pigs?
Lower-calcium options include red and green leaf lettuce, romaine, bell peppers, cucumber, cilantro, and small portions of carrot tops. Limit (but do not eliminate) higher-calcium greens like parsley, kale, and dandelion greens — they are still nutritious in small amounts. Avoid spinach and Swiss chard as daily staples in stone-prone pigs.
Still Not Sure if Your Guinea Pig Needs a Vet?
When you're not sure if this is wait-and-see or call-tonight, Voyage AI Vet triages in under 2 minutes. Describe what you're seeing in chat, share photos of your guinea pig's urine spots in the cage, any straining, or the food bowl, or hop on a live video call if you want a second pair of eyes. Every answer comes with citations to the actual veterinary literature it's pulling from — so you see exactly where the guidance comes from, not just a chatbot's word.