What you need to know about Parvo in Dogs

I think most dog owners have a general idea about parvovirus prior to getting a new puppy, they may have heard stories of puppies having the condition, or maybe had a friend of a friend who experienced a loss due to the disease.

In the veterinary profession we see many puppies every year that have Parvo – and though survival rates are better than they used to be, it is still a very serious disease. Over the years as a Registered Veterinary Technician I have monitored and assisted in providing care for many Parvo puppies, and I don’t know how many sleepless nights I have had in my career waiting to know if a pet will make it through the night.

What I hope is that this breakdown of parvo in dogs will help you recognize possible areas where your pup might get the disease, what the signs of parvo are in dogs so you can get help right away for your pup, what preventatives we currently have available, and what treatment options there are, along with some emerging therapies.

I firmly believe that the more informed a pet owner is, the better decisions they can make for their pup, and the more proactive they can be about their pup’s health. Because if we don’t know, we can’t do anything. So let’s start with the basics…

What is Parvo in Dogs?

Parvo, or the canine parvovirus is a viral infection that primarily attacks the intestinal lining and the bone marrow – causing inflammation to the gastrointestinal tract, and a decreased immune response. This combination makes infected dogs have trouble absorbing nutrients and maintaining their hydration, while also being more prone to secondary infections.

How do dogs get Parvo?

Canine Pavovirus Fact Sheet - type of disease, how it's spread, where it attacks, incubation period, age of onset.

Puppies and dogs get parvo by exposure to infected particles of the stool of another animal – either via inhalation or ingestion. Since Parvo lives for over a year in soil – it can easily be acquired by puppies while walking in grassy/dirt areas. Often a dog will walk or run through an area, and either stir-up the dirt then they will later groom themselves ingesting the infection. Wild animals can get parvovirus as well – coyotes, wolves, raccoons, and foxes – being the most common wild populations in the USA that can get the disease.

Once the virus enters the body it travels to the nearest lymph nodes (usually in the throat) and takes up resistance. This period is known as the incubation period – and it can last between 3-7 days. After that the infection travels through the bloodstream and focuses its attention on the rapidly dividing cells of the bone marrow and the intestines.

Some breeds such as Rottweilers, Doberman Pinschers, Staffordshire Terriers, Springer Spaniels, German Shepherds and Labradors that are more likely to get parvovirus than other breeds, however all breeds are susceptible to the infection.

Puppies are more susceptible than adult dogs to parvovirus. The most common age that dogs get parvo is between 6 to 20 wks of age. Older dogs that get parvovirus tend to show less severe symptoms.

What are the clinical signs of Parvo in Dogs?

Typically early clinical signs of parvovirus are gastrointestinal in nature, but then can progress to affecting other systems due to septicemia and shock.

  • Lethargy
  • Loss of Appetite
  • Vomiting
  • Low or High body temperature
  • Abdominal Pain / Bloating
  • Very loose watery stools with, or without blood

How do we diagnose Parvo in Dogs?

Example of fecal swab for Parvovirus diagnosis in dogs.

After an examination with your veterinarian, if they suspect that your pup might have parvovirus they will probably recommend doing what is called a Fecal Parvovirus ELISA test (or SNAP test). Basically what they do is they collect a very small amount of stool (about a gram), then using a ELISA test kit – add a solution that will let us see if the antibodies for parvovirus are present in the stool. A positive test means that your pup has parvovirus, and will need further supportive therapies.

Depending upon your veterinarian, they may have the test on site, or this might be something they have to send out to a lab overnight.

If you suspect your puppy has parvovirus – please call your veterinarian and discuss your options prior to arrival. Some smaller hospitals may refer you directly to a 24/7 facility because they do not offer overnight hospitalized boarding, and some smaller hospitals also might not have testing kits of Parvo on site. 

If your hospital does offer both of those services calling beforehand is still ideal in order to limit possible contamination of the facility (and other pets coming to the hospital!). Often larger veterinary hospitals will have you come in a special door into an isolation room if they suspect your puppy has parvovirus.

How do we treat Parvo in dogs?

What does supportive care for dogs look like in Parvovirus Treatment - IV fluids, Nutritional Therapy, Medications.

Treatment for parvovirus is supportive care – there is no drug currently on the market that “kills” parvovirus. Depending upon the individual dog’s condition, and how their immune system responds to fight off the disease will largely tell your veterinarian what they need to do in order to help your pup. Most treatment plans for parvo include…

  • Intravenous fluids to maintain hydration, and electrolyte balance
  • Nutritional therapy – this may come in the form of highly palatable canned diets, or syringe feeding. Nutrition’s primary goal during hospitalization is to feed the intestinal cells which will aide in recovery later. Meaning that only very small amount of food is given. Too much can make other symptoms (like vomiting and diarrhea) worse.
  • Medications to control clinical signs – such as anti-diarrheals and anti-vomiting medications.
  • Medications to help with secondary infections (or infections that take hold due to the puppy’s poor immune health while fighting the disease) – such as certain types of antibiotics

Typically treatment for parvovirus will last from one to two weeks – and will require 24/hr hospitalization for at least the first 5-7 days. According to the American Veterinary Medical Association survival rate is between 68 to 92% – different strains of parvovirus have different survival rates, and the later treatment is started, the lower the survival rate – so early recognition is important.

Emerging Therapies for Parvovirus Treatment:

Fecal Transplant, an emerging therapy for dogs with parvovirus.

Since parvovirus is such a serious condition there is still ongoing research happening to find new supportive therapies and treatments for puppies dealing with this condition.

  • Fecal Transplant: the gut contents or fecal matter from a healthy pet are transplanted into the sick puppy. The use of this treatment has been shown to significantly helping with loose stools associated with parvovirus – which can help with nutrient absorption and fluid loss (which is one of the major killers of pups who get this disease).
  • Tamiflu® (Oseltamivir): though Tamiflu doesn’t not directly help with parvovirus infection it does actually help with secondary infections within the intestinal tract which can exacerbate the disease.
  • Plasma Transfusions: donated plasma from other dogs may contain anti-bodies and immunity from another dog, along with proteins, albumin, and other elements to help pet’s repair cells and recover from the disease.
  • Septi-Serum: has been used regulatory at Auburn University Teaching Hospital, however remains largely controversial. It contains antibodies that are extracted from horses that can bind with GI invading bacteria. However since the product is horse and not dog in origin it can cause immunological issues if given more than once.
  • Neupogen: contains a genetically engineered hormone that works to stimulate bone marrow function in dogs, potentially helping bone marrow and immune system recovery. However studies have not shown a significant change to survival rates with the addition of this product.

How to disinfect your home when your puppy has parvovirus:

I know every pet owner doesn’t want to think about this – however if the situation DOES happen to you, you will want to know how to disinfect your home in order to limit exposure to your pup and other dogs.

The best household cleaner to kill parvovirus within your home will be bleach – you can use it at 1 part disinfecting bleach to 30 parts water. You spray the solution onto the area and leave it for about 15 seconds prior to rinsing away. If using bleach on fabric or furniture – test on a small area prior using. All bedding, toys, and other items should be cleaned with diluted bleach or replaced. Steam cleaning at 120-130 degrees fahrenheit can also be effective for carpets. However there is no way to adequately clean soil or other natural surfaces. 

Your yard should be considered “contaminated” for 1 year after treatment.

Meaning that you should not have any un-vaccinated puppies in your home or yard until after that period of time.

How do we prevent Parvo in dogs, and how effective is the Parvo Vaccine?

Dog parks are not good options for socialization of puppies under 20 wks old.

Puppies who have not been fully vaccinated should avoid areas where a potentially high population of dogs are – such as dog parks – where a puppy may come into contact with a dog who is unknowingly shedding the disease.

About 80% of adult dogs that get parvovirus actually do not display ANY clinical signs – thus an owner may not even realize they are sick.

Does this mean your puppy should avoid ALL types of socialization until two weeks after the last vaccination (around 20 wks of age) – NO! There are ways to both socialize your pup and mitigate risk. Try puppy classes where vaccinations and parasite screenings are required, and classes that are held on easily disinfected surfaces. You can also visit friends with gentle and well mannered older dogs that are vaccinated. Walks in low-traffic areas on hard surfaces are also relatively safe.

And of course practice socialization at home to different sights, objections, sounds, textures, restraints etc. Remember 80% of socialization actually has more to do with the environment than actual dog to dog interaction. You will have plenty of places and things to explore while avoiding those high risk areas.

The good thing about parvovirus is that it is largely preventable with vaccination. What you need to understand is vaccines work in two ways – the first is providing immunity to the individual, and the second is providing what is called “herd immunity” to the community. These two factors help to prevent the spread of parvovirus within a community/area.

So how does the vaccination work?

Puppies drinking milk from momma to get immunity from pavrovirus.

What you need to understand is that if the mom already has been vaccinated and/or has immunity to parvovirus – in the first couple of days while the puppies are nursing on mother’s milk (getting the colostrum) – they receive immunity from mom. This immunity will vary widely depending upon the levels within the mom – moms vaccinated near when they were bred will have the highest immunity. After getting the colostrum the immunity in the puppies will half every 10 days. 

Now the problem with the vaccination is that they will compete with the mother’s own immunity given to the puppies. So if you vaccinate too soon when the puppies have momma’s immunity, the vaccine cannot take hold, and may potentially compete with or weaken the immunity given by the mother. And if you vaccinate too late, there may be a time where a puppy is not covered by any immunity at all – making them more susceptible to parvovirus.

Lots of research has been done looking at the statistically best time to give vaccinations to puppies, while also looking at the risks associated with disease transmission during this peak infection time. However you can actually CALCULATE when the best time to give vaccinations is by testing the immunity within the mother, then calculating the half-life. But this type of testing is usually only done during scientific studies at university, and rarely if ever done in practice.

Parvo Vaccination Schedule?

Vaccination Schedule - traditional vs. alternative

In order to mitigate both of these risks – the parvovirus vaccination is typically done in a series after the weaning process (between 6-8wks of age) – at each injection you are trying to catch the right moment when mom’s immunity fades enough for the vaccine immunity to take hold, without having any large gaps in immune coverage.

Traditionally puppies receive the parvovirus vaccination every 3-4 weeks from 6-8 wks of age until 16wks of age. About two weeks after this series is completed a puppy is considered “immunized” by traditional medicine terms, and your puppy will not need another parvovirus vaccination until a year later, then every three years after that. 

An alternative vaccination schedule has been recently suggested for puppies – where a puppy gets two vaccinations – one at 12 wks of age, and another at 16 wks of age – then a titer test is done at 20 wks to check immunity, then yearly thereafter. This puppy vaccination schedule has not been generally accepted by the veterinary community as a whole, and does potentially introduce risk to parvovirus infection – as puppies are most susceptible to the disease between 6 to 16 wks of age.

Info-graphic on herd immunity. HERD IMMUNITY is where a majority of dogs have immunity, either through vaccination or getting the disease, and can protect vulnerable populations.

However, you should know that there is a small portion of dogs that actually NEVER RESPOND to vaccination. Meaning that they got the vaccines on the correct schedule, but their immune system just doesn’t respond. These dogs largely rely on herd immunity in order to not contract the disease – meaning that all the other dogs around them will not get parvo, then the likelihood of them getting it will be very small.

Another subset of puppies and dogs that rely on herd immunity for protection is pups that have severe reactions to vaccinations, or that are immune compromised (like those that autoimmune disease or are undergoing drug therapies – like chemotherapy – that cause decreased immune function). For these pets the vaccination risk may be too high, and vaccination is not necessarily recommended. If you think your pup falls into one of these categories, speak with your veterinary team – they may recommend not vaccinating at all or an alternative vaccination schedule (depending on the situation).

If you have concerns about vaccinations – have an open and honest conversation with your veterinary team. And if for whatever reason you would like to do an alternative vaccination schedule for your puppy – I would ask if your veterinarian offers this option prior to making your first puppy wellness examination. Some veterinarians, due to the potential risk associated with an alternative schedule, will not offer it, and also will not carry titer tests in house. If you are looking to do an alternative vaccination schedule for your puppy it is best to work with an integrative or holistic veterinarian – as they will most likely be more familiar with titer testing.

Speak to your veterinarian about your pup and their medical history at each annual examination to see what vaccinations your pup actually needs – Parvovirus IS considered a core vaccination, however AAHA now generally accepts the use of titering yearly in lou of vaccination after the initial puppy vaccination series. However, keep in mind that some boarding, daycare and grooming facilities may not accept dogs with just titers for liability reasons.

How do you know if your dog has an immune response to the vaccination?

Picture of Parvovirus Titer Test.

You can do a titer test! A titer test looks at the antibodies present within the bloodstream to see if an immune response has occurred due to the vaccination or not. This can tell you if the vaccine worked! Typically titer tests are performed 1 month after vaccination to confirm immune status, and then can be performed yearly there-after to check immune status.

There are two different types of titer tests available – one is a snap test – I basically think of it as a “red light”, “green light” test – you mix the blood with a solution and then use a special testing kit. If you have a dot appear – it means your pup has at least a certain minimum antibody level present. If you don’t see that dot appear, it means the antibodies are not present/active. Which suggests that a pet may need to be re-vaccinated.

The second is a full antibody titer test where the blood is sent to a lab and they actually give you an antibody number – this can often give you more information as to how close you are to the threshold of needing to re-vaccinate. The american animal hospital association has recently accepted the use of titers for parvovirus in the place of vaccination after the initial puppy vaccination series.

What I hope you have come away with is two things – one is that YOU as a pet owner are your pet’s eyes and ears – you are the one they rely on to get them to the veterinarian when they are sick. And in the case of parvo in dogs – recognizing the signs and getting there sooner rather than later can completely change the course of this disease. The other thing I hope you take away from this post is that parvovirus is largely a preventable disease. Vaccinations are very effective against this infection, and though survival rate is high – your pup may have lasting effects of the illness. I know my pup Ash battled with gastrointestinal problems for years after having parvovirus as a puppy – and he still has a rather sensitive GI tract.

So what have you done in the past, or what do you plan to do going forward with your pup regarding parvovirus? Have you done titer testing before? What have been your experiences? I’d love to hear from you! Comment below or join the conversation on Instagram. I know my pups are definitely out of the “high risk” phase associated with parvovirus, so we are considering doing titer testing moving forward, so I’ll be curious to see how their levels look this December!

Stay healthy my Canine Health Nuts!

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