What Is Parvo in Dogs? Symptoms, Treatment and Prevention
Updated: 3 days ago
There's a long list of things to stay on top of when you bring a dog home. Vaccines, food, training, walks and vet checks are all part of it. But one word worries even experienced owners, and that's parvo. Canine parvovirus is one of the most serious illnesses a dog can catch, and it moves fast. It's also largely preventable, which is why every owner should know about it. It's also why I'd carry a young puppy to watch the world, rather than putting them down on the ground, until your vet says they're covered. Here's what parvo is, how it spreads, the signs to watch for, how it's treated and how to protect your puppy.
THE SHORT ANSWER
Parvo, or canine parvovirus, is a highly contagious virus that attacks a dog's gut and immune system. It mainly affects puppies and unvaccinated dogs, but adult dogs can catch it too. It spreads through infected poo and can survive for months on ground, shoes, bowls and bedding. Signs usually show three to seven days after exposure and include severe vomiting, diarrhoea that's often bloody, tiredness, not eating and dehydration. There's no drug that kills the virus, so vets treat the symptoms with fluids and supportive care, and early treatment saves lives. Vaccination is the best protection. Until your puppy's vaccine course is finished, carry them in public places and keep them away from unknown dogs.
IN THIS POST
ā What parvo is
ā Signs of parvo
ā Prevention
ā Can vaccinated dogs get parvo?
ā Recovery
ā FAQs
What parvo is
Canine parvovirus attacks cells that divide quickly, especially the lining of the gut. That causes severe vomiting and diarrhoea and makes it hard for a dog to absorb food and water.
It also weakens the immune system, so the body struggles to fight back. Puppies are hit hardest because they haven't built up immunity yet.
How dogs catch parvo
Parvo spreads through contact with infected poo, either directly or through anything it has touched. That includes grass, pavements, food bowls, leads, hands and the soles of your shoes.
The virus is tough. It can survive in the environment for months and isn't killed by most household cleaners. Your puppy can catch it without ever meeting a sick dog. Some dogs are at higher risk:
puppies between about six weeks and six months old
dogs who haven't had their full vaccine course
dogs from shelters or poor breeding conditions
dogs in busy multi-dog homes
Signs of parvo
Signs usually show three to seven days after a dog is exposed. They can get worse quickly, so acting early matters. Watch out for:
severe, repeated vomiting
diarrhoea, often bloody and with a strong smell
tiredness and weakness
not eating
quick weight loss and dehydration
a high or unusually low temperature
If you see any of these, especially in a puppy or an unvaccinated dog, ring your vet straight away. Tell them you're worried about parvo before you arrive, so they can keep other dogs safe.
Diagnosis and treatment
Your vet will examine your dog and usually run a quick poo test, often with blood tests too. There's no medicine that kills the virus itself, so treatment supports the body while it fights the infection.
That usually means a drip for fluids, medicine for sickness and pain, antibiotics to prevent other infections and careful feeding. Many dogs need several days in a hospital ward. Sadly, not every dog survives, but survival is much more likely with fast, intensive care.
Prevention
Vaccination is the most important protection against parvo. Puppies usually start their vaccines at around six to eight weeks old, with further doses a few weeks apart until around 16 weeks. Your vet will tell you the exact plan, including adult boosters.
Until your puppy's course is complete and your vet says they're protected, don't put them down in public places where unknown dogs may have been. That includes parks, pavements, vet waiting room floors and communal water bowls. You can still carry your puppy out to see the world and train lots at home. Read should you start training before vaccinations are done?
Can vaccinated dogs get parvo?
Vaccines give strong protection, but no vaccine is 100 percent. Occasionally a vaccinated dog still catches parvo, though they usually have milder symptoms and are more likely to recover.
That's why keeping up with vaccines and boosters matters. It protects your own dog and the other dogs around you.
Cleaning up after parvo
A dog who recovers from parvo can still shed the virus for several weeks. Keep them away from other dogs and follow your vet's advice on when it's safe to mix again.
Clean everything your dog touched, including floors, crates, bedding, toys, bowls and outdoor areas. Use a disinfectant your vet recommends as effective against parvovirus, because regular household cleaners won't kill it. Diluted bleach can work on hard surfaces, but always ask your vet for the right strength and keep your dog away until it's rinsed and dry.
Recovery
After parvo, your dog's body needs time to rebuild. Bring food back slowly, keep exercise gentle and let them rest plenty.
You can still do calm training at home while they recover. Short sessions of easy skills, sniffing games and settling on a mat are all gentle on the body. Read puppy socialisation windows.
If your dog had parvo
Watching your dog fight parvo is exhausting and frightening. Many owners feel guilty afterwards, even when they did everything right.
Parvo is a tough virus and it doesn't mean you failed. What matters is that you acted, asked for help and looked after your dog. Lean on your vet for support, and take care of yourself too.
RENEE'S TIP
Put a pair of "outside shoes" by the door while your puppy is waiting for their vaccines. Take them off before you walk into the house, and wash your hands after touching other dogs. It's a small habit, but parvo travels easily on shoes and hands.
QUICK CHECK
ā Parvo is highly contagious and can survive for months on the ground
ā Signs include vomiting, bloody diarrhoea, tiredness and not eating
ā Ring your vet straight away if you're worried
ā Follow your vet's vaccine plan, including boosters
ā Carry your puppy in public places until they're protected
ONE-TO-ONE HELP
Help with your puppy's early training
If your puppy can't go out yet or is recovering from illness, I can help you plan safe training at home in an online Dog Behaviour Consultation from wherever you are.
Online on Teams, wherever you are. 30 or 60 minutes.
FAQs
What is parvo in dogs?
A highly contagious virus that attacks a dog's gut and immune system, causing severe vomiting and diarrhoea.
How do dogs catch parvo?
Through infected poo or anything it has touched, like grass, shoes, bowls and bedding.
What are the first signs of parvo?
Vomiting, diarrhoea that's often bloody, tiredness and not eating. Ring your vet straight away.
Can a vaccinated dog get parvo?
It's rare. Vaccinated dogs who do catch it usually have milder symptoms and recover more often.
When can my puppy go outside safely?
When your vet says their vaccine course is complete. Until then, carry them in public places.
ABOUT THE AUTHOR
Renee Patience Ā· National Dog Trainer of the Year 2025
Founder and head trainer of Paws Academy, with more than 30 years training dogs and a Level 6 Diploma in Applied Canine Behaviour. Renee has competed in agility, obedience and heelwork to music across the UK, including at Crufts and Olympia, has appeared on CBBC, and is the author of the Modern Training Guides and the Modern Breed Handbook series. Pictured with her boxer, Kookie.
