
Parvovirus creates fear in even the most seasoned dog owners and veterinarians. Hearing the word parvo brings images of dying puppies to mind. It can break your heart instantly.
Parvo is a very serious illness and I'm going to tell you all you need to know about it.
But this post isn't to scare you. I want you to feel confident and calm when your vet mentions parvovirus at your puppy's first visit.
Let’s dive deeper into what parvovirus is ... so you have a better understanding of how it can affect your dog. I'll also tell you how to prevent it naturally and how you can naturally manage parvovirus at home.
But If your puppy already has parvovirus ... don't waste time. Jump straight to Home Care For Your Parvovirus Puppy.
What Is Parvovirus?
Parvovirus (CPV) is a viral infection that spreads by contact with infected dogs. Dogs can also pick up the virus through contact with infected feces (which you can bring home on your shoes).
Parvovirus can live in soil for months, depending on the temperature. It quickly attacks the rapidly dividing cells in the lining of the digestive tract. But it can also attack young immune cells.
Puppies are more severely affected than adults. The hallmark of parvo is blood-stained feces. The feces often have a yellowish tinge and a very distinct and unpleasant smell.

What Are The Symptoms Of Parvovirus?
Parvo itself rarely kills dogs. It's the associated dehydration and secondary infection that can be deadly.
Some breeds of dog seem to be more susceptible to parvo. The black and tan breeds are more vulnerable. Keep this in mind if your puppy is a Rottweiler or Doberman Pinscher. You'll want to know the signs and symptoms so you can act fast.
The symptoms of parvovirus include:
How Is Parvovirus Diagnosed?
Fortunately, parvovirus is easy for vets to diagnose. Your veterinarian can analyze a stool sample for the parvovirus antigen with a SNAP test. This test accurately detects parvovirus antigen in the stool in about 10 minutes.
Your vet will also run bloodwork while you wait. This is to check your puppy's immune cells and hydration. It'll show how badly the virus is attacking his cells.
NOTE: If your puppy has been recently vaccinated, the SNAP test will not detect the vaccine strain of parvovirus (CPV-2)

A Closer Look At Conventional Prevention With The Parvovirus Vaccine
One reason vets advocate vaccination for parvovirus is that the cost of treating the illness can be high. Vet bills totalling in the thousands are not unusual.
Most puppy owners are willing to pay these large bills to save their puppies ... but not everyone can afford it.
At first glance, it makes sense. Vaccinate your puppy to avoid costly vet bills or loss of life in the future. But here’s what they don’t tell you (and it’s pretty important).
Your puppy can beat parvo naturally. Yes, this deadly virus can be beat if you're up for the challenge.
When you look at the facts, the fear hype won't alarm you so much. You can then start making more intelligent vaccination decisions.
Base those decisions on science instead of fear. Once you do, you may find that what first seems like a simple vaccine is decidedly complicated.
So let’s review what you need to consider when you make vaccination decisions for your puppy.
#1 Is The Disease Dangerous?
Despite the media scares and dire veterinary warnings, parvo has a survival rate of about 85%. This doesn’t mean 15% of puppies die from parvo.
It means that 15% of puppies who are exposed to it and actually catch it will die. But the survival rate is greatly influenced by the treatment options. We’ll get into this a bit later.
#2 Is The Parvovirus Vaccine Safe?
It's difficult to determine the rate of adverse reactions for vaccines. That’s because they’re rarely reported back to vets and manufacturers.
Most adverse cases you hear about are extreme cases. These include puppies who develop hives or hydrocephalus within 24 hours. But few people recognize the chronic diseases that vaccines create. Chronic illness can take days, weeks, months or years to develop after vaccination. That means people (and vets) often don't make the connection.
Remember this when your dog develops a chronic health issue after any vaccine.
So let’s review in more detail some of the safety concerns with the parvo vaccine.

The Risk Of Toxin Exposure
When you vaccinate your puppy, the maternal antibodies will often block the vaccine. The immune system your puppy gets from his mother responds as it would to a real virus. So vets repeat the vaccinations, hoping the maternal antibodies wear off so the vaccine can work.
I’ll share more about maternal antibodies in a bit.
But there's something maternal antibodies can’t do. They can't protect your puppy against the chemical soup of adjuvants in vaccines.
These chemicals can include:
So … by giving your puppy a series of vaccinations, you inject him with more and more toxins. This weakens his immune system and increases his risk of illness later.
The purpose of the toxins in vaccines is to stimulate an exaggerated immune response. This helps the body respond to the small amount of virus in the vaccine.
Unfortunately, this heightened reaction can also cause chronic disease, including autoimmune problems.
A Risk Of Autoimmune Disease
The Purdue studies (in the 1990s) revealed how vaccination can cause chronic disease. Although labeled as inconclusive at the time, they provided some important information.
They found vaccinated dogs developed autoantibodies to many of their own biochemicals, including:
This should have sounded some pretty serious alarms!
Instead, the researchers found good homes for the dogs. They decided long-term follow-up wasn’t necessary. They felt they needed more research before taking any action.
A Link To Cancer
The AVMA Vaccine-Associated Feline Sarcoma Task Force also initiated several studies in the 1990s. They wanted to find out why 160,000 US cats a year were getting terminal cancer at their vaccine sites.
These studies acknowledged that vaccine-induced cancer exists. But the Task Force decided the best plan was to continue vaccinating. The focus shifted to figuring out which cats were most likely to die.
They also suggested vaccinating cats in their tails. That makes it easy to lop them off if they develop cancer from the vaccines.
Dogs are not immune to this risk.
The Journal of Veterinary Medicine shared a study on vaccine-induced cancers in dogs. This article also noted that cancers were found at vaccine injection sites.
It can happen in humans too. The Salk Polio vaccine was shown to carry a monkey retrovirus ... because they cultivated it on monkey organs. The monkey virus SV40 produces inheritable cancer and turns up in human cancer sites.
A Risk To The Heart
Dr Larry Glickman, who spearheaded the Purdue studies, said:
“Our ongoing studies of dogs show that following routine vaccination, there is a significant rise in the level of antibodies dogs produce against their own tissues.
"Some of these antibodies have been shown to target the thyroid gland, connective tissue… red blood cells, DNA, etc. I do believe that the heart conditions in Cavalier King Charles Spaniels could be the end result of repeated immunizations by vaccines containing tissue culture contaminants that cause a progressive immune response directed at connective tissue in the heart valves.”
The heart disease Glickman is talking about is cardiomyopathy. Cardiomyopathy in dogs used to be very rare.
But, since the parvo pandemic of 1978, cardiomyopathy has become more prevalent. Many breeds now get it. So breeders screen their dogs for this fatal disease.
Vaccination is likely the cause of most cases of cardiomyopathy. Prior cases of the condition were not associated with parvo.
Parvovirus Vaccination Can Lead To More Parvo
A final safety concern is that vaccinated dogs are virally active. This means for 21 days after vaccination, they shed the virus every time they ...
So … when you weigh the safety concerns of the parvo vaccine, there’s a lot to consider.
Now, let's review how effective the vaccine actually is against parvo.
# 3 Is The Parvovirus Vaccine Effective?
Many vets and pet owners used to believe more is better on the question of vaccines. But we now know there are real dangers associated with vaccinations and over-vaccination.
I said I’d get back to maternal antibodies. Here's more explanation.
The goal of the repetitive, conventional puppy vaccine schedule is to catch the window when maternal antibodies are low. This can prevent maternal antibodies from blocking the vaccine.
The mother’s first milk, called colostrum, protects puppies. Colostrum contains maternal antibodies against diseases.
Your puppy’s immune system doesn't mature until around six months of age. So he depends on this passive immunity against disease.
His maternal antibodies will weaken over time ... but that time varies among dogs and even breeds.
So the decline rate of maternal antibodies for parvo is unpredictable. Some can last as long as 26 weeks. So that's the reason the parvo vaccine often won’t protect your puppy when you give it early...
... And why veterinarians vaccinate puppies on a repeating schedule. They often start at 6 to 8 weeks old, vaccinating every 2 to 4 weeks until 16 weeks. Some vets say the first vaccine primes the immune system and the second one creates immunity …
…But that's not true.
One vaccination, given when the maternal antibodies are low, will protect your puppy. This fact has been common knowledge for more than 30 years.
Let’s look at what one company found when they tested the efficacy and maternal antibodies.
Zoetis Testing For Parvovirus Vaccine Efficacy
The good news is, manufacturers need to show that these vaccines protect puppies. Most can prove protection if they give them at 12 weeks of age.
The bad news is, they do this with high titer/low passage vaccines. High titer/low passage is a fancy way of saying there is a lot more antigen (parvo).
Some even contain up to 65 times more! This also means a vaccinated puppy will shed more virus into the environment.
Zoetis tested the parvovirus response in their combination high titer vaccine. They vaccinated the 3 groups of puppies at different ages:
- 6 weeks
- 9 weeks
- 12 weeks
They then assessed the puppies' immune response by measuring their titers to parvovirus.
- At 6 weeks, only 52% of the puppies had developed an immune response.
- At 9 weeks, 88% of the puppies responded.
- At 12 weeks, 100% of the puppies responded.
Vaccinating puppies at 6 to 8 weeks is a high-risk, low-value practice. At that age, it's highly likely the maternal antibodies will block the vaccine.
So by vaccinating him while he’s young, you’re potentially exposing your puppy to parvo, by being at the clinic. And you're limiting the chance of vaccine success.
It would be safer to socialize your puppy on the street with healthy dogs. Save the trip to the vet until he’s old enough that the vaccine is likely to work.
NOTE: The Virbac Disease Watchdog reported 28% of puppies and 11% of adults were infected by parvo ... after they had been vaccinated for it. There are a variety of reasons for this but the most common is the presence of maternal antibodies.
Strangely, the public access for the Watchdog report is no longer available. However you can always ask your vet to provide you with the adverse events listed for any vet product. They can obtain this by calling the manufacturer's technical service veterinarian.
The USDA (US Department of Agriculture) also publishes reports of vaccine adverse events. But their system is complex and hard to access for non-veterinarians.
Other Reasons Puppy Vaccinations Can Fail To Protect
As well as vaccinating at the wrong time, there are a couple of other things you need to watch for.
Parvovirus
Previous exposure to the actual virus can play a role in your dog's vaccine response. If your puppy comes into contact with the virus he will develop an immune response. These antibodies can block the vaccine ... much like maternal antibodies.
Vaccinated or not ... don’t expose your puppy to areas where he might catch parvo. These areas include:
A Stressed Immune System
Vaccines also fail when your puppy is sick or stressed at the time of vaccination. When his immune system is compromised, he can’t build an immune response. It also means he’ll be more likely to get the disease he’s being vaccinated for.
Once again, it makes little sense to vaccinate a puppy at 6 to 8 weeks of age when you consider the stress of ...
... In fact, vaccine failure is likely at this age.
Other immune stressors for your puppy include:
NOTE: The Canine Adenovirus-2 (CAV-2) vaccine can suppress the immune system for 10 days. (Phillips et al, Effects of vaccines on the canine immune system. Can J Vet Res 1989). This fact and along with zero cases of Canine Infectious Hepatitis in North America in at least 12 years ... means that the CAV-2 component in vaccines delivers little value at a pretty large cost.
The Type Of Vaccine
Polyvalent vaccines also increase the risk of vaccine failure. These are vaccines that contain more than one disease. And vets use them a lot, often injecting your puppy with 4 or 5 viruses at once.
Modified live vaccines (MLV) replicate in the host over about 10 days. So, while your pup is immune-compromised, the virus can multiply and cause the disease.
Polyvalent vaccines increase this effect. The more antigens in a vaccine, the more viral replication your puppy will experience at once. This makes his immune system more likely to get disease from an antigen. The risk is even greater in small dogs.
"The immune system is a finite resource and can only be stretched so far, so it is safest to avoid giving multiple antigens in one vaccine."
Moore et al JAVMA, 2005
This is likely why there are disease outbreaks in animal shelters. The dogs are stressed, often malnourished, and they get polyvalent vaccines.
Their Immune systems are defenseless … so they get the disease and spread it to others.
Vets and immunologists have stated that MLV shouldn’t create disease in the host.
The problem is, they can’t prove it.
Except for rabies, nobody has checked whether the strain of virus infecting dogs is the vaccine strain.
If they're not tracing the strain of the infectious disease ... how can they claim the disease wasn't caused by a parvo or distemper vaccine?
A human example is the polio vaccination. It’s created several disease outbreaks. The number of children paralyzed by polio doubled from 2008 to 2009. The cause was the mutated oral vaccine.
More troubling was the type 2 strain of polio in the vaccine. It had been eradicated in 1999 by the Global Polio Eradication Initiative. But, with vaccine mutations, it's reappeared in vaccinated populations.

So, will you be vaccinating your puppy for parvovirus?
You need to make your own vaccine decision because, in the end, you're the one who has to deal with the consequences.
What's crucial is that you decide based on science and not on a false belief – or fear.
[Related: Nature Vs The Parvovirus Vaccine: Which Will You Choose?]
The fact is, you can’t eliminate risk for your puppy. You can only choose which risk you can accept.