Canine Parvovirus - "Parvo"
Education and Prevention Procedures.

* Parvo Virus is considered “ubiquitous” (existing or being everywhere at the same time: constantly encountered: widespread) and can infect a dog or puppy in any environment. Incubation time can be as quick as 3 days, or as long as 14 days.

So, according to what we have learned about Parvo is that the best you can do is to knock the volume of parvo down in your environment, but, you will never completely kill it. The severity of infection in a puppy is a direct reflection of the amount of parvo virus it has encountered.

A parvoviral infection can be picked up ANYWHERE though it is easier to pick up an infection in an area where an infected dog has been present simply because of the larger amounts of virus present in a contaminated area.

Whether an individual dog gets infected or not depends on the number of viral particles the dog experiences, what kind of immune experience the dog has had with the virus before (vaccinated? previously infected? how much past exposure?), and how strong the individual dog is (stress factors, diet, etc.)

A typical/average infectious dose for an unvaccinated dog is 1000 viral particles. For some dogs far less is needed. For other dogs, far more is needed. An infected dog sheds 35 million viral particles (35,000 TIMES the typical infectious dose) per OUNCE of stool.

Parvovirus

The original Parvo crossed from cat Panleukopenia (a Parvo virus) and affected the gut of dogs. We had Parvo in dogs that caused little issues so this new diarrhea Parvo was named Parvo 2, affecting only dogs. The newer strains of Parvo, including 2A & B, reproduced in wildlife and cats, but still preferred canines. 2c Parvo will readily go back and forth to wildlife and cats where it reproduces and spreads. That gives the new strains a competitive advantage and keeps the wild virus in the environment.

Parvovirus is a highly contagious virus which causes vomiting and diarrhea, and often leads to death in susceptible dogs. Parvovirus is a very durable virus, and can remain in the environment for many months. Parvovirus is primarily spread to other dogs by the fecal-oral route,

however it can be spread on hands, feet, clothing, tools, rodents and flies traveling from location to location. Dogs may carry the virus on their fur and feet even if they themselves do not get ill.

Vaccination will greatly reduce the risk of dogs becoming ill with parvovirus, however no vaccine will protect 100% of animals. In puppies, maternal antibodies interfere with the ability of the vaccine to provide a long-term effect. If the bitch was vaccinated for parvovirus in the past, she will give antibodies to her puppies, via her milk (colostrum). Maternal antibodies gradually wear off, and become ineffective in most puppies between four and sixteen weeks.

In young puppies, maternal antibodies protect them against disease; however vaccinations will NOT WORK while maternal antibodies are present. The picture below was adapted from Greene’s Infectious Diseases of the Dog and Cat.

The picture demonstrates how maternal antibodies (‘mean antibody titer’) decrease over time, and how vaccinating while maternal antibodies are higher than the ‘minimum titer to block vaccine’ will not protect puppies. Because of this risk, we recommend vaccinating puppies every three weeks until they are 16 weeks old, in an effort to make the ‘window of susceptibility’ as small as possible and to increase the likelihood that our vaccine protocol will protect our puppies from parvovirus. Vaccinating more often that every three weeks is not effective. Once maternal antibodies are no longer a factor, the vaccine protects the puppy against parvoviral infection within 2 to 7 days; one vaccine will protect the puppy against disease in this situation. (No “booster” per se is needed with this vaccine.) This may occur at any time from the first vaccine to the last, depending on the amount of maternal antibody the puppy received.

If you would like to know for sure if your puppy has resistance or titer against Parvo, you can request a blood titer test from your veterinarian.

Here is our protocol for treatments and vaccinations:

Before your new puppy comes home with decontamination procedures completed, AND for the first three weeks AFTER you bring your puppy home:

2.) Make sure your dog is properly vaccinated. Puppies should receive their first vaccines at 6-8 weeks of age; boosters should be administered at three-week intervals until the puppy is 16 weeks of age, and then again at one year of age. Previously vaccinated adult dogs need boosters every year.

3.) Limit your puppy’s exposure to other dogs and animals that leave and reenter the home (they can be carriers, even if they are not ill) until he’s had his first three vaccinations.

4.) Avoid walking yourself or taking your puppy to places where your puppy could be exposed to parvovirus from unvaccinated dogs. HIGH RISK AREAS: I-5 or Highway rest areas, dog parks, pet stores, play groups, and other public high risk areas should be avoided by you and your puppy until your puppy is fully vaccinated.

5.) When visiting your vet for wellness check-ups and vaccinations, carry your puppy in your arms outside and leave him on your lap, or wait in your car while waiting for your appointment. Walking where other dogs have walked and gone to the bathroom, or allowing anyone other than the veterinarian touch your puppy will increase your puppy’s risk of contracting disease.

THE VIRUS IN THE ENVIRONMENT

Parvovirus is very difficult to kill and can live in the environment for many months to over a year.

Because the canine parvovirus is not enveloped in fat the way the distemper virus is, canine parvovirus is especially hardy in the environment. It is readily carried on shoes or clothing to new areas (which accounts for its rapid worldwide spread shortly after its original appearance). It is able to overwinter freezing temperatures in the ground outdoors.

Regular soaps and disinfectants DO NOT kill parvovirus. Areas that cannot be cleaned with bleach or Trifectant / Virkon may remain contaminated. Remember, the virus can survive on a variety of objects, including food bowls, shoes, clothes, carpet and floors.

Given that this is such a tough virus to destroy, many people want to know exactly what they must do to disinfect an area that has contained an infected dog or how long they must wait before safely introducing a new dog to a previously contaminated area.

Here is what we know about how contaminated an environment is likely to be:

Infected dogs shed virus (in their stool) in gigantic amounts during the 2 weeks following exposure. Because such enormous amounts of virus are shed, there is a HUGE potential for environmental contamination when a infected dog has been there.

It is important to realize that because the canine parvovirus is so hardy in the environment, it is considered "ubiquitous." This means that NO ENVIRONMENT is free from this virus unless it is regularly disinfected.

A parvoviral infection can be picked up ANYWHERE though it is easier to pick up an infection in an area where an infected dog has been present simply because of the larger amounts of virus present in a contaminated area.

ENVIRONMENTAL DECONTAMINATION

In most households, owners want to know how to disinfect their homes to create a safer environment for the other dogs there or to create a safe environment for a new puppy.

Despite decontamination procedures, parvovirus remains virtually impossible to completely remove from an environment. The goal of decontamination is to reduce the number of viral particles to an acceptable level.

Indoor decontamination:

Indoors, virus loses its infectivity within one month; therefore, it should be safe to introduce a new puppy indoors one month after decontamination procedures are implemented:

1.) We recommend steam cleaning to kill any virus particles present. Steam clean carpets, floors and furniture the puppy will have access to.

2.) The best and most effective disinfectant against viruses (including parvoviruses) is BLEACH. (1/2 cup bleach in a gallon of 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 (1/2 cup bleach in a gallon of water) is needed to kill the virus.

3.) Trifectant / Virkon: These are highly effective, broad-spectrum disinfectants that can kill 99.99% of major bacteria and viruses within minutes. Proven to kill bacteria and fungi in less than five minutes and Parvovirus in less than ten minutes. These are penetrating disinfectants. They are safe around young puppies. Can be used indoors or outdoors. They penetrate organic matter and get the virus. This is the one we use to spray our gravel runs. Use the Tabs for smaller jobs and the Powder for large jobs. Virkon® S Disinfectant and Virucide dilutes easily in water for effective manual or machine operation.(sprayers). Solutions are stable for 7 days. One gallon is sufficient to treat 135 sq. feet. 10 minutes is the maximum necessary contact time.

Outdoor decontamination:

Disinfection becomes problematic for non-bleachable surfaces such as lawn. Outdoors, if good drainage is available, thorough watering down of the area may dilute any virus present.

Freezing is completely protective to the virus. If the outdoors is contaminated and is frozen, one must wait for it to thaw out before safely introducing a new puppy.

Shaded areas should be considered contaminated for seven months. (with no decontamination procedures implemented)

Areas with good sunlight exposure should be considered contaminated for five months. (with no decontamination procedures implemented).

WE RECOMMEND TREATMENT WITH: Trifectant / Virkon: These are highly effective, broad-spectrum disinfectants that can kill 99.99% of major bacteria and viruses within minutes. Proven to kill bacteria and fungi in less than five minutes and Parvovirus in less than ten minutes. These are penetrating disinfectants. They are safe around young puppies. Can be used indoors or outdoors. They penetrate organic matter and get the virus. This is the one we use to spray our gravel runs. Use the Tabs for smaller jobs and the Powder for large jobs. Virkon® S Disinfectant and Virucide dilutes easily in water for effective manual or machine operation.(sprayers). Solutions are stable for 7 days. One gallon is sufficient to treat 135 sq. feet. 10 minutes is the maximum necessary contact time.

Behavior/Socialization

The primary socialization period of puppies is between 3 and 13 weeks. This period is critical for development of primary social relationships with humans and other animals. Puppies that are confined during this period are significantly more likely to develop behavioral problems (primarily fear and aggression) than puppies that are provided a socialization program. Puppies isolated from conspecifics (other puppies) until 16 weeks of age, were significantly more likely to display fearful behavior and be aggressed upon by other pups. They were unable to develop a positive relationship with other dogs Puppies raised in isolation until 16 weeks lose the capacity to exhibit playful behavior toward strangers. Previous research demonstrates that socialization is a critical step in the development of behaviorally healthy dogs.

Puppies with parvovirus die within a few weeks of contacting the virus; puppies with behavior problems die within a few years. Because of the temporal disconnect between acquiring the disease (behavior or parvovirus) and mortality, the need to develop comprehensive socialization programs in puppies is often underestimated. A recent study demonstrated that puppies who attended socialization classes were more likely to be retained in their homes than those that did not.

Behavioral problems are the primary cause of relinquishment of dogs to shelters. Thus, they are also the leading primary cause of mortality of dogs in animal shelters.Because of this, it is important to implement socialization activities for puppies which maximize socialization AND protect them from infectious diseases.

Here are links to some of the research we have consulted in regards to parvo and parvo prevention:

Please follow the guidelines here to decontaminate your own environments and keep your new puppies as safe as possible while they complete their puppy series of vaccinations. Prior to your pup going home with you we are sending all of you a gallons worth of powdered disinfectant called Virkon aka Trifectant. this will now be part of our normal preparation for all of our puppy families.

Here is more info on this product and where to purchase more if needed: