Canine parvovirus is a contagious virus that can infect any dog at any age, but is usually found in puppies less than 6 months old.

A dog infected with parvo is contagious for about a month after you first notice signs.  The dog will pass a large amount of the virus in its stool during the first two weeks after infection. The virus can survive for a long time, in almost any environment.


Parvo is a viral infection. It is transmitted through:

  • Contact with feces from an infected dog
  • Contact with every day objects that are infected: clothing, shoes, equipment etc.
  • Infected rodents and insects

Parvo is common in places with overcrowding and poor sanitary conditions.


There are two forms of parvovirus. If your dog has one form, it will not necessarily have the other form.

Intestinal form:

  • Vomiting liquid
  • Dry mouth
  • Lack of appetite
  • Depression
  • Bloody diarrhea with a horrible odor
  • Low body temperature or fever over 103 degrees

Cardiac form (usually occurs in puppies less than 16 weeks old):

  • Crying or can’t seem to breathe normally (gasping for air)
  • Weakness and inability to play
  • Puppy doesn’t want to nurse
  • An irregular heartbeat

Not all infected dogs have every symptom and these signs can often be caused by other diseases.

If you notice any of the above symptoms, go to your veterinarian immediately. Parvo can be fatal if left untreated.


The most effective way to test for parvo is an ELISA test. Your veterinarian will perform a rectal swab and test it for parvovirus antigens in your dog’s feces.

Your veterinarian may also complete the following to confirm diagnosis of parvo:

  • Urine and blood tests
  • Tests for intestinal parasites
  • Abdominal x-rays and ultrasounds: checks for blockages in the intestines


Your veterinarian will recommend the best treatment for your dog based on its medical history, age, condition, etc., and may include:

  • IV Fluid therapy: for rehydration and nourishment
  • Medication: to prevent secondary infection and control vomiting and diarrhea Hospitalization (2-4 days): to monitor white blood cell count and fluid levels

To help your dog recover, you will need to provide the following:

  • Rest: your dog may try to play once it feels better; don’t encourage that
  • Isolation: avoid the outdoors and other animals until fully recovered
  • Medication: give prescription in full; let your veterinarian know if your dog refuses
  • Special diet: small portions of bland food when your dog can eat solid food again

Your dog is recovering from intestinal tract damage and may have a loose stool or no stool at all for the first few days.


The best prevention for parvovirus is to follow the vaccine schedule that your veterinarian recommends. The standard schedule includes a series of parvovirus vaccines. Keep your newly vaccinated puppy away from other dogs for 2 weeks after the last shot.


Left untreated, parvo can be fatal.  (It is rarely fatal by itself.  Death is usually the result of shedding intestines, blood and nutrition loss, secondary infections or dehydration caused by the vomiting and diarrhea.)

Caught early enough and properly treated, many dogs will recover completely and return to normal within a month, with no permanent effects.

It is important to realize that because the canine parvovirus is so hardy in the environment,

it is considered to be ubiquitous. 

This means that NO ENVIRONMENT is free from this virus unless it is regularly disinfected.


A parvoviral infection can be picked up ANYWHERE!  Whether an individual gets infected or not depends on the number of viral particles the dog is exposed to, what kind of immune experience the dog has had with the virus before (vaccinated? previously infected? mother’s colostrum? past exposure?), and how strong the individual dog is (stress factors, diet, etc).


Indoor Decontamination

Indoors the virus can be active for a long time.  This means it should be safe to introduce a new puppy that is vaccinated against parvo  INDOORS no earlier than 6 months after the previous pet has fully recovered.


Outdoor Decontamination

Freezing is completely protective to the virus.  Therefore outdoor decontamination cannot begin until AFTER THE GROUND HAS THOROUGHLY THAWED.

  • Shaded areas should be considered contaminated for at least 7 months
  • Areas with good sunlight exposure should be considered contaminated for at least 5 months.



Parvovirus remains virtually impossible to completely remove from the environment.  The goal of decontamination/disinfection is to reduce the number of virus particles to an acceptable level.  The best and most effective disinfectant against viruses (including parvovirus) is BLEACH. 

 One part bleach is mixed with 30 parts water (aka 1/8 cup bleach to 3 ¾ cup water) and is applied to bowls, floors, surfaces, toys, bedding, and anything contaminated that is colorfast or for which color changes are not important.  At least 10 minutes of contact time with the bleach solution is needed to kill the virus.  Steam cleaning is also able to kill the virus.


Disinfection becomes problematic for non-bleachable surfaces such as carpet or lawn.  Outdoors, if good drainage is available, thorough watering down of the area may dilute any virus present.  Since carpet is indoors, it may be best to simply wait a good 6 months or so for the virus to die off before allowing vaccinated puppies access to the area. Unvaccinated puppies are more at risk of contracting the disease, and should not be allowed in the environment that has had exposure to parvo virus.