Parvovirus in dogs: symptoms, spread and prevention

This guide is general information, not veterinary advice. If you're worried about your dog, speak to your vet.

Parvovirus, or parvo, is a highly contagious virus that can kill dogs. It damages the lining of the gut and weakens the immune system (PDSA). Puppies and unvaccinated dogs are most at risk, and vaccination is the best protection (Blue Cross; PDSA).

Symptoms to look out for

Symptoms usually appear three to seven days after a dog is exposed (PDSA; Dogs Trust). Look out for:

• Severe diarrhoea that's foul-smelling, watery and often bloody (PDSA; Dogs Trust; Blue Cross)
• Vomiting (PDSA; Blue Cross)
• Very low energy (lethargy) or seeming depressed (PDSA; Blue Cross)
• Loss of appetite (Dogs Trust; Blue Cross)
• A very high or very low temperature (PDSA)
• Pale gums (PDSA)
• Tummy pain (PDSA)
• Collapse (Blue Cross)

If your dog has simply been in contact with parvo but has no symptoms, PDSA says there's no need to call. Watch them closely and ring for advice if you're concerned (PDSA).

How parvo spreads

Most dogs catch parvo while out exploring (PDSA). It spreads in the poo and vomit of infected dogs (Blue Cross), and dogs can catch it just by sniffing another dog's poo (Blue Cross).

• Before and after illness: infected dogs shed the virus in their poo even before they show symptoms (Dogs Trust). PDSA says shedding starts three to four days after infection and carries on for a couple of weeks after symptoms clear (PDSA).
• In the environment: sources agree the virus is long-lasting, though they put it differently. PDSA says it can survive for months to years (PDSA). Blue Cross says it can survive in the grass at a park for at least six months, and possibly much longer (Blue Cross).
• On objects: it can travel on shoes, leads, collars, bowls, clothes, toys and bedding, and even on human hands (PDSA; Blue Cross; Dogs Trust).
• Places: it can be found almost anywhere dogs go, such as gardens, parks and fields (PDSA), as well as pavements and floors (Dogs Trust).

Who is most at risk?

Parvo is especially serious in unvaccinated dogs and in puppies under six months old, whose immune systems are less able to fight it (PDSA). Blue Cross says puppies aged six weeks to six months and unvaccinated dogs are most at risk (Blue Cross). It also notes that outbreaks are most often seen in towns and cities with a large population of unvaccinated dogs (Blue Cross).

Treatment and recovery

There's no cure for parvo. Dogs need intensive care to control their symptoms while their body fights the virus (PDSA; Dogs Trust). That usually means a fluid drip, anti-sickness medication, careful feeding and isolation from other pets. Antibiotics don't kill the virus but may be used for other infections (PDSA; Dogs Trust). Blue Cross says the average hospital stay is five to seven days (Blue Cross).

A dog's chance of survival is much higher if they reach the vet quickly. Parvo is nearly always fatal without treatment, and sadly some dogs die even with it (PDSA). Treatment can cost hundreds or even thousands of pounds, so speak openly to your vet about costs (PDSA).

After your dog comes home

• Your dog can still be infectious for two to four weeks after recovering, so keep them away from other dogs and public spaces for that time (PDSA).
• Keep any unvaccinated pets completely separate for at least a month after recovery, and get them vaccinated straight away (PDSA).
• The virus can stay in your home and garden for months to years. If you've lost a dog to parvo, PDSA advises waiting until a new puppy is fully vaccinated before bringing them home (PDSA).

How to prevent parvo

• Vaccinate. Vaccination is the best and only way to prevent parvo. Puppies need two to three parvo vaccines, then regular boosters for life (PDSA). Even after the puppy course, a dog without regular boosters is still at risk (Dogs Trust). See our vaccinations guide and puppy vaccination timeline.
• Keep puppies off the ground in public until your vet says they're protected. Carry them instead (PDSA).
• Buy or rehome responsibly. See the puppy with their mum where they were raised, more than once. Mum should be up to date with her vaccines (PDSA).
• Wash your hands after handling a dog that might be infected, so you don't carry the virus to other dogs (Dogs Trust).

No vaccine is 100% guaranteed, so a vaccinated dog can occasionally still catch parvo. Vaccination is still by far the best way to cut the risk (PDSA).

Can people catch parvo?

No. People can't catch parvovirus from dogs, and the human parvovirus is a different strain (Blue Cross; Dogs Trust). People can, though, carry the dog virus from one dog to another on their clothes, shoes or hands (Blue Cross).

Finding a vet in Liverpool

If you're worried, ring your vet first. Browse our Liverpool vets directory to find a practice near you, and check who covers out-of-hours emergencies.

Out-of-hours emergencies in Liverpool: Medivet 24 Hour Alder, 410 Eaton Road, West Derby, L12 3HG, says it is open 24 hours a day, 365 days a year. Call 0151 220 4668 (Medivet, checked 18 Oct 2026). Vets Now Liverpool, based in the PDSA Pet Hospital on Woolfall Heath Avenue, Huyton, L36 3YD, opens from 6pm on weeknights, from noon on Saturdays, and all day on Sundays and bank holidays. Call 0151 271 5727 (Vets Now, checked 18 Oct 2026). Always ring before you set off, and ask your own vet which service covers their out-of-hours calls.

More in our dog health series

• How dog illnesses spread
• Dog vaccinations explained
• Puppy vaccination timeline
• Kennel cough
• Lungworm in dogs
• Leptospirosis in dogs

See all our dog health and first aid guides

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