Parvovirus is one of the most resilient and most fatal puppy diseases. It survives on surfaces for months. It kills by destroying the lining of the intestine, leading to blood loss, dehydration, and overwhelming infection. Vaccination protects against it; nothing else really does.
How a puppy catches it
Through contact with infected faeces or any surface — a leash, a pavement, a shoe — that has been in contact with infected faeces. A vaccinated adult dog can carry parvo on their paws and bring it home. Pet stores, parks, and even vet clinic floors are common exposure points.
Why the vaccine schedule is the way it is
Puppies are born with maternal antibodies from their mother's milk. Those antibodies protect the puppy for about six to ten weeks — but they also block the vaccine from working. The schedule of three or four shots between six and sixteen weeks exists because we don't know exactly when the maternal antibodies drop in any individual puppy. We give shots repeatedly to catch the window the moment the puppy can respond.
Until the series is complete, be paranoid
Don't walk on public ground. Don't allow contact with other dogs whose vaccination status you don't know. Don't take a young puppy to a pet store. Socialisation is critical at this age, but do it in controlled places: a friend's clean garden, your living room with vaccinated dogs, indoor puppy classes that require proof of vaccination.
The symptoms
Severe vomiting, profuse bloody diarrhoea with a characteristic foul smell, lethargy, refusal of food and water. A puppy can go from playing to collapsed in under 24 hours.
What survival looks like
Hospitalisation, IV fluids, anti-nausea drugs, antibiotics for secondary infections, and a feeding tube in severe cases. Treatment costs in India range from ₹15,000 to ₹50,000 depending on length of stay. Survival rates with aggressive treatment are 70 to 90 per cent. Without treatment, parvo is nearly always fatal.
If you're adopting a street puppy
The risk is much higher. Quarantine them from other dogs in the home until they've completed at least two parvo shots. Disinfect everything they've touched with bleach — parvo shrugs off most household cleaners.
