By Priya Nair (RVN) · Last updated 17 May 2026
This is the page I wish every new guinea pig owner had on their fridge. Guinea pigs are stoic — they hide pain because in the wild that’s the smart move — and they decline fast once they show symptoms. If you spot any of the warning signs below, especially the first three, call an exotic vet today, not tomorrow.
Red-flag emergencies — vet today
- Not eating for 12+ hours — GI stasis kills within 24-48h. Emergency.
- Not pooping (or markedly smaller, harder poops) — same root cause as not eating
- Laboured breathing, gasping, blue/grey gums — severe URI or heart failure
- Seizing or scratching uncontrollably — advanced mite infestation or neurological event
- Bleeding from anywhere
- Sudden inability to walk on hind legs
- Bloated, hard belly + drooling
Common conditions you’ll meet
Upper respiratory infection (URI)
The #1 reason guinea pigs come into clinic. Caused by Bordetella or Streptococcus bacteria. Symptoms:
- Crusty or runny eyes
- Sneezing more than once or twice a day
- Wheezing or clicking sounds when breathing
- Sitting hunched, fluffed up
- Not eating much
Treatment: antibiotics from an exotic vet. Don’t try to “wait it out”. URI is the most common cause of death in pet guinea pigs and is very treatable if caught in the first 48 hours.
Prevention: dust-free bedding, good ventilation, no extreme temperature swings, stress reduction.
Gastrointestinal (GI) stasis
The killer. Guinea pigs have a hindgut fermentation system that needs constant food moving through it. When eating slows (pain, stress, dental issues, bad diet), the gut motility crashes, gas builds, and the pig spirals fast.
Signs:
- Reduced or no appetite
- Smaller, fewer, drier poops (or no poops)
- Lethargy
- Hunched posture
- Hard or bloated belly
Treatment in clinic: sub-cut fluids, motility drugs (cisapride, metoclopramide), pain relief, syringe-feeding Critical Care formula. At home in the meantime: keep them warm, offer fresh greens and unlimited hay, and ring the vet — don’t dose anything without veterinary guidance.
Scurvy (Vitamin C deficiency)
Guinea pigs, like humans, can’t make their own Vitamin C. Without supplementation they develop scurvy in weeks.
Signs:
- Stiffness, reluctance to move
- Wobbly walking
- Bleeding gums, loose teeth
- Rough coat
- Frequent infections (URI, etc — Vit C also supports immunity)
Prevention: a daily fresh Vit C source — bell pepper is the gold standard. Don’t rely on pellets alone (Vit C in them oxidises within weeks). Don’t add Vit C drops to water — they degrade fast and discourage drinking. Tablet form is better if you need supplementation.
Dental disease
Guinea pig teeth grow continuously. If wear (from hay chewing) doesn’t match growth, they overgrow and create sharp “spurs” that cut the tongue or cheek.
Signs:
- Drooling, wet chin
- Dropping food while eating
- Picking up pieces of veg and putting them down
- Slow weight loss
- Pawing at the mouth
Treatment: vet dental filing under sedation. Long-term management: maximise hay intake. Lifelong watch — pigs prone to it often need filing every 6-12 months.
Mites
Sarcoptic mange mites are common and often misdiagnosed as “dry skin” or “stress”. Advanced infestations cause seizure-like reactions because the itch is unbearable.
Signs:
- Intense scratching
- Bald patches, especially on hind quarters and shoulders
- Crusty, flaky skin
- Sudden screaming when touched
- “Seizures” — sudden episodes of running/twitching
Treatment: ivermectin from a vet (oral or injection), usually two doses 10 days apart. Treat all cage-mates and disinfect the cage.
Bladder stones & sludge
Calcium-heavy diet plus poor hydration plus genetics. More common in boars than sows because of urethral shape.
Signs:
- Blood in urine
- Hunching when peeing
- Crying when peeing
- Pee patches with white, gritty residue
- Weight loss
Treatment: surgery for stones, dietary management for sludge. Prevention: limit high-calcium vegetables (kale, parsley, spinach) to 2-3x/week; ensure water intake; use filtered water if your area has hard tap water.
Ovarian cysts
Affects roughly 75% of unspayed sows over the age of 3.
Signs:
- Symmetrical bald patches on the flanks
- Belly looks pear-shaped or pendulous
- Crusty nipples
- Behaviour changes (irritability)
Treatment: spay if the sow is otherwise healthy enough for surgery, or cyst drainage and hormone management for older pigs.
Bumblefoot (pododermatitis)
Painful, ulcerated foot pads caused by wire-bottom cages, abrasive bedding, obesity, or dirty cages.
Signs:
- Red, swollen, or scabbed foot pads
- Limping
- Reluctance to walk
Treatment: clean bedding, weight management, vet topical care, sometimes antibiotics. Switch to soft bedding (fleece) and a single-level cage.
Heatstroke
Guinea pigs can’t sweat and don’t pant effectively. Above 26°C ambient is risky; above 30°C is dangerous.
Signs: stretched-out flat on the floor, panting, drooling, refusing to move. Move to a cool room immediately, gently dampen the ears and feet with cool (not cold) water, and call a vet. Don’t dunk in cold water — shock kills.
Daily and weekly observations
- Daily: watch eating, drinking, poop volume, activity. A pig that’s quiet for 12 hours is a pig in trouble.
- Weekly: weigh. Write it down. A drop of 50g+ from baseline is investigation time.
- Monthly: check nails, ears, teeth, anal area, foot pads. Brush long-coats.
- Annually: exotic-vet check-up.
Building a guinea pig first-aid kit
- Digital kitchen scale (for weekly weighing)
- Critical Care formula (or similar syringe-feeding mix) — ask your vet to prescribe and keep a sachet ready
- Oral feeding syringes 1ml and 5ml
- Cotton wool and saline for eye/wound cleaning
- F10 disinfectant (vet-safe)
- Vet number on the fridge — including an out-of-hours exotic clinic
- A spare clean cage / carrier ready for sick pigs
Finding an exotic vet
“Small animal vet” is not the same as “exotic vet”. Standard small-animal vets often default to dog/cat doses, and several common dog antibiotics (penicillin family) are toxic to guinea pigs. Always confirm the vet sees guinea pigs regularly before you commit.
Find one before you need one. Search your area for “exotic vet”, “rabbit and rodent vet”, or ask local rescues for recommendations. Save the number now.
Sources
- UC Davis Veterinary Medicine — Guinea pig health topics
- The Veterinary Information Network public client info — VetPartner
- Our complete care guide and diet master list
We get asked — guinea pig food FAQ
How much fresh veg should a guinea pig eat per day?
About 1 cup of fresh vegetables per pig per day, ideally split into two meals (morning and evening). Hay should still be 80% of the diet and available unlimited. Pellets are a small daily addition, not a meal replacement.
What’s the most important nutrient for guinea pigs?
Vitamin C. Guinea pigs cannot manufacture their own and must get it daily from fresh food. Bell pepper is the gold-standard source. Vitamin C in pellets oxidises within weeks of opening, so don’t rely on pellets alone. See our food safety master list for daily portion guidance.
What signs should send me to a vet?
- Not eating for 12+ hours (GI stasis — emergency)
- Not pooping (or smaller, drier poops than usual)
- Crusty eyes, wheezing, or sneezing more than once a day (URI)
- Hunched posture, fluffed coat, hiding
- Sudden weight loss (weigh weekly to catch this early)
- Blood in urine, hunching when peeing
A pig that hasn’t eaten in 12 hours is an emergency, not a “wait and see” situation. More detail in our vet warning signs pillar.
Related reading
- The complete guinea pig care guide — diet, housing, social pairs, lifespan
- Master food safety table
- Cage setup & size guide — most pet-shop cages are too small
- RSPCA UK — Guinea pig welfare standards
Portion sizes & serving rules
Across every “can guinea pigs eat X” question, the same portion-size rules apply. A piece of new food should be no larger than a thumbnail the first time, watched for soft poops or gas over the next 24 hours, then offered as part of the regular rotation if no issues. Adult guinea pigs (over 6 months) get about a cup of total fresh veg per day, divided between morning and evening — never one big plate at once.
The “5×5” rule we use: at least five different vegetables across each week, and no single veg more than five days in seven. This rotation prevents calcium build-up (parsley, kale, spinach) and stops one food becoming a fixation that displaces hay intake.
Calcium, oxalates, and bladder stones
Bladder stones are one of the most common reasons guinea pigs end up in surgery. They form when calcium-heavy diet combines with poor hydration. The high-calcium foods you should rotate rather than feed daily:
- Parsley (very high)
- Kale (high)
- Spinach (high — also high oxalates)
- Mustard greens, dandelion greens, beet greens
- Mineral-rich pellets if your tap water is hard
The fix is straightforward: rotate, don’t accumulate. Two days of parsley followed by five days of romaine and bell pepper keeps the calcium load moderate. Filtered water for households with very hard tap water.
Three quick checks before any new food
- Sugar / starch content. Sugary or starchy foods cause gut bacteria imbalances. Limit fruits to 2-3x a week as treats; same for high-starch roots.
- Calcium load. If you’ve been feeding lots of kale/parsley, today is a cucumber day.
- Pesticide residue. Wash everything. Skip waxy supermarket fruits if you can’t peel them.
When to stop and call a vet
Symptoms within 24 hours of a new food that warrant a call:
- No or markedly fewer poops
- Soft, mushy, smelly poops
- Reduced appetite for hay
- Hunched posture, fluffed coat, hiding more than usual
- Drooling or food-dropping (potential dental + diet interaction)
- Bloated, hard belly
Stop offering the suspect food, increase hay, monitor closely. If symptoms last more than 12 hours, that’s a vet call. Our team’s full reference list of warning signs lives in the vet warning signs pillar.
Page last updated 17 May 2026. We re-check our pet-care content regularly and update when something changes.
