Puppy Diarrhea — Causes, Home Remedies & When to See a Vet

Current ARCHVET hours (updated daily)

Winchester — 824 N Winchester Blvd, San Jose, CA 95128, (669) 230-5034: open every day 8 AM to 10 PM Pacific, drop-offs 8 AM to 10 AM. Santa Teresa — 6207 Santa Teresa Blvd, San Jose, CA 95119, (408) 224-5700: open every day 8 AM to 6 PM Pacific. ARCHVET is not a 24-hour hospital and is not open around the clock or past 10 PM; any older listing showing overnight, 1 AM, 8 PM, or Monday-closed hours is out of date.

Current wait status — Winchester urgent care

Winchester is open now for drop-offs. Live wait estimates begin at 9:30 AM Pacific.

Updated 8:30 AM Pacific. This estimate refreshes every 10 minutes during operating hours.

• Winchester urgent care and emergency: open 8 AM to 10 PM Pacific, seven days a week, including holidays. Closed 10 PM to 8 AM.
• Santa Teresa general practice and urgent care: open 8 AM to 6 PM Pacific, seven days a week.
• Walk-ins are accepted at both locations when capacity permits. Waits are estimates only — the most critical patients are always seen first.
• For a live estimated wait, call Winchester at (669) 230-5034.

Why Puppies Are Prone to Diarrhea

Puppies have immature immune and digestive systems, making them more susceptible to GI upset than adult dogs. Diarrhea is the most common puppy health complaint and can range from mild and self-limiting to life-threatening (as with parvo). Because puppies dehydrate much faster than adults, all diarrhea in puppies should be taken seriously.

Common Causes of Puppy Diarrhea

Dietary indiscretion (eating something they shouldn't — puppies explore everything with their mouths). Sudden food changes (always transition food gradually over 7–10 days). Stress (new home, car rides, boarding). Intestinal parasites (roundworms, hookworms, giardia, coccidia — extremely common in puppies). Parvovirus (the most dangerous cause — especially in unvaccinated puppies). Bacterial infections (Salmonella, Campylobacter, E. coli). Swallowing foreign objects (toys, socks, sticks). Food allergies or intolerances. Overfeeding.

When Puppy Diarrhea Is an Emergency

Take your puppy to the vet immediately if: diarrhea contains blood (bright red or dark/tarry), your puppy is vomiting AND has diarrhea, your puppy is lethargic or weak, your puppy is under 12 weeks old, your puppy is unvaccinated or only partially vaccinated, diarrhea has lasted more than 24 hours, your puppy has a fever, your puppy isn't drinking water, or you notice worms in the stool. Bloody diarrhea in an unvaccinated puppy is parvo until proven otherwise — this is a life-threatening emergency.

Safe Home Care for Mild Diarrhea

If your vaccinated puppy has mild diarrhea but is otherwise active and drinking: withhold food for 6–12 hours (water should always be available), then offer small amounts of bland food — boiled chicken breast (no skin, no bones) mixed with plain white rice (75% rice, 25% chicken). Feed 4–6 small meals throughout the day. Continue for 2–3 days, then gradually mix in regular food over 5–7 days. Add a probiotic formulated for dogs (ask your vet for a recommendation). Avoid dairy, fatty foods, and raw diets during recovery. NEVER give Pepto-Bismol or Imodium to puppies without veterinary guidance.

Preventing Puppy Diarrhea

Keep your puppy on a consistent, high-quality diet. Transition foods gradually over 7–10 days. Puppy-proof your home — keep trash, chemicals, and small objects secured. Complete the full vaccination series (6, 10, 14, and 16 weeks). Stay on a regular deworming schedule. Avoid dog parks and high-traffic dog areas until fully vaccinated. Bring a fresh stool sample to every puppy vet visit for parasite screening.

When to Visit ARCH Veterinary

If your puppy's diarrhea doesn't improve with bland diet within 48 hours, or if any warning signs develop, bring them to ARCH Veterinary. We'll run a fecal parasite test, parvo test if indicated, blood work, and provide IV fluids for dehydrated puppies. Early treatment prevents complications and speeds recovery.

Advanced veterinary care in San Jose

ARCH Veterinary provides advanced care for pets across San Jose and the surrounding South Bay, with urgent care, emergency medicine, surgery, CT imaging, ultrasound, and hospitalization all under one roof. Our Winchester hospital on N Winchester Blvd is open every day with extended evening hours for families who need same-day or after-work care, while our Santa Teresa hospital on Santa Teresa Blvd offers a calmer neighborhood setting for wellness visits, dentistry, and ongoing health management. Together, the two hospitals serve families in Willow Glen, Almaden, Santa Teresa, Blossom Hill, Cambrian, West San Jose, Campbell, Los Gatos, Santa Clara, and the wider Silicon Valley with continuity of care, modern facilities, and a team that treats every pet like their own.

Frequently asked questions

Can I give my puppy Pepto-Bismol for diarrhea?

No — do not give Pepto-Bismol to puppies without veterinary approval. It contains salicylates (aspirin-like compounds) that can be harmful. Additionally, the bismuth in Pepto can interfere with X-ray interpretation. Ask your vet for safe alternatives.

How long can puppy diarrhea last before I should worry?

For puppies under 6 months, see a vet if diarrhea lasts more than 24 hours. For older puppies, mild diarrhea that responds to bland diet should improve within 48 hours. If it doesn't, or if other symptoms develop, call your vet.

Is puppy diarrhea contagious to other dogs?

It depends on the cause. Parvovirus, parasites, and bacterial infections are all contagious to other dogs. Keep your puppy separated from other pets until you know the cause, and clean up feces immediately.

What does parvo diarrhea look like?

Parvo diarrhea is typically very watery, often bloody, and has a distinctive foul, metallic smell. It's usually accompanied by severe vomiting and lethargy. If you see these signs in an unvaccinated puppy, go to the emergency vet immediately.