Parvovirus in dogs, or CPV (canine parvovirus), is one of the main diseases we vaccinate our pets against in Australia. In this article we discuss what “parvo” actually is, as well as the symptoms, the prognosis, prevention, treatment and disinfection methods. We also answers some frequently asked questions.
Firstly, a favour to ask: many first time pet owners are completely unaware that parvovirus even exists. After reading this article please be sure to share it with anyone you know who has a new puppy. This disease is easy and cheap to prevent and yet very expensive to treat. You may just save a life simply by sharing!
What is Parvovirus?
Canine parvovirus is a deadly and highly contagious virus that mainly affects young puppies and unvaccinated dogs. It comes in two forms:
1. The gastrointestinal form: the most common type, which targets the lining of the intestine causing sloughing of the intestinal wall and internal bleeding.
This form also targets a dog’s bone marrow, depleting their white blood cell count, which normally helps to fight off infections.
2. The cardiac form: less common, this form mainly attacks the heart muscle of foetuses, leading to myocarditis and death.
For the purpose of this article we will be discussing the common gastrointestinal form of canine parvovirus infection.
How do dogs get Parvo and how is it spread?
Parvovirus in dogs is spread by direct contact with faeces from infected animals. Once the faeces breakdown into the ground, the virus can survive in that area for long periods (up to 7 months), particularly in shady areas with moist soil.
Virus particles from these areas can then be transferred to other environments by people on shoes, clothing, car tyres, etc.
To put it into perspective, according to virologists, a typical infectious dose for parvovirus in a dog is 1000 viral particles. An infected dog can shed 35 million parvo virus particles (35,000 times the typical infectious dose) per ounce of faeces. It’s no wonder it is so contagious.
In spaces where many dogs come into contact with each other, the chances of picking up parvovirus are increased. Dog parks, beaches, multi-dog households, breeders, dog kennels and even vet hospitals can be prime environments for parvovirus spread without proper disinfection protocols being in place.
Is Parvovirus Contagious to Humans?
Zoonotic spread is the spread between species, so for instance from a dog to a cat or a dog to a human. Thankfully, each species has their own version of parvovirus that stays within its species.
Your cat can’t contract parvovirus from your dog and neither can you.
The Dreaded Incubation Period
When a puppy is diagnosed with parvovirus, the immediate tendency is to think they must have acquired it from an outing in the last day or two.
Unfortunately, parvovirus also has quite a long incubation period of around 3-14 days. During this time an infected dog will be carrying the virus but appear otherwise healthy.
A common scenario is when a new owner picks up a healthy looking puppy from somewhere where parvo vaccinations are not given. A week later that healthy looking puppy is suddenly fighting for it’s life with parvovirus. It can be a devastating experience for any pet owner.
Canine Parvovirus in Australia
Vaccination has done a great job in reducing the number of cases presenting with parvovirus in Australia. However, there are certain areas that remain hot spots for the disease.
There has been a resurgence of cases across many metro areas in recent times, most likely due to a lapse in people keeping up to date with their dog’s vaccinations.
Dogs Most Susceptible to Parvovirus
Young dogs are more prone to contracting parvovirus than adult dogs. Some breeds of dog have also been shown to be more susceptible than others, including:
- German Shepherds
- Pit Bulls
- Doberman Pinschers
- Springer Spaniels
Parvovirus in dogs symptoms can be separated into different stages of the disease:
Early stages of parvo
Healthy puppies are normally boisterous and full of beans. During the early stages of parvo, clinical signs include puppies becoming tired easily and showing a reluctance to play. They will usually stop eating, show a disinterest in food and may have a fever.
During the second stage your puppy may begin vomiting and have profuse rancid smelling diarrhoea. Faeces infected with parvo smells like a sickly sweet, metallic kind of smell which is partly caused by the tinges of blood often seen in it.
Infected dogs can initially present with one or all of these symptoms.
It’s important to note that young puppies like this dehydrate very easily. When this happens their bodies naturally try to conserve water. This means that diarrhoea may not be immediately evident.
However, as soon as a parvo puppy is rehydrated (usually by IV fluids), profuse diarrhoea follows.
The marked dehydration in a young puppy can also look like sudden weight loss.
Due to their small size, young puppies succumb very easily to the disease. The sloughing of their intestinal wall and subsequent blood loss means that during this stage a puppies gums may be a very pale white colour.
They are severely dehydrated. Their body temperature is also usually very low (hypothermia) as pets go into shock. These dogs present laying on their side quite unresponsive.
Death during this stage is imminent.
If your puppy has not been vaccinated and becomes unwell, your vet will run a parvovirus snap test or rapid test.
These tests are designed to detect the parvovirus in your pet’s faeces and then show a coloured dot or band if positive.
Your vet will take a small faecal sample via a rectal swab for the test.
The test takes around 10 minutes to run so a quick answer can be given if the test is positive.
Occasionally, false negatives can occur. This means that the test can indicate a negative parvovirus result even though your pet actually still has parvovirus. Obviously, this result is not as helpful!
This can occur for a number of reasons, but especially if the test is performed quite early in the diseases progression. During the early stages, active shedding of the virus into the dog’s faeces may not be occurring yet.
When a negative test is received, but your vet remains highly suspicious of parvovirus based on the symptoms and patient history, further testing may be required.
A general blood profile can be used for additional evidence. Usually there is a broad depletion of the different white blood cell types.
When a positive result or high suspicion based on further testing is acquired, treatment can begin.
Parvovirus in Dogs Treatment
There is no cure for parvovirus. Canine parovirus treatment is aimed instead at supporting your puppies body whilst it attempts to mount its own immune response to the virus.
Treatment normally requires 5-10 days of intensive care at a veterinary hospital.
Due to the highly contagious nature of the virus, puppies receiving treatment for parvovirus are kept in an isolation ward where strict personal protective equipment, hygiene and disinfection protocols are maintained.
Parvovirus treatment is targeted at:
- Preventing dehydration. The loss of fluids caused by vomiting and diarrhoea can take a massive toll on young puppies. To counteract this loss, your vet will administer intravenous (IV) fluids.
- Preventing secondary infections. Because the virus causes sloughing of the intestinal wall and depletion of the immune system, infected dogs are prone to secondary bacterial infections from the gut. To target this, a vet will administer a combination of broad spectrum intravenous antibiotics.
- Reducing vomiting and nausea. To prevent further fluid loss by vomiting and to make a pet a little bit more comfortable, anti vomiting medication is administered.
- Providing pain relief. The damage to the intestinal wall caused by parvovirus can be quite painful. Pain relief such as opiate medication is given to counteract this visceral pain.
- Protecting the lining of the gastrointestinal (GI) tract. Gastro-protectants help to line the gastrointestinal tract to prevent further ulceration. Stomach acid inhibitors are also administered to reduce the acidity of the GI tract to allow faster healing.
- Parasite treatment. Many pets that are unvaccinated also haven’t been properly wormed either. Intestinal worms latch onto the intestinal lining of a pet and consume blood. When your pet is already bleeding internally, the last thing they need are worms. Its not uncommon for a large volume of worms to be expelled from these puppies after proper worming treatment is administered. Flea control is also important as fleas can consume blood but also pass on tapeworm.
- Providing circulatory support. Aside from IV fluids, if a puppy loses enough blood and becomes severely anaemic with pale white gums, they may need a blood transfusion.
- Boosting the immune system. Some vets utilise anti-viral medications, interferon, as well as plasma from vaccinated pets to try and bolster a pet’s depleted immune system. Interferon is a type of protein that is released by a host in response to the presence of a virus. Commercial products are made using these proteins. Some studies indicate that interferon use can result in a 6.4 fold reduction in parvovirus mortality rates in dogs.
- Providing nutritional support. Puppies that are this sick do not want to eat, at all. However, proper early nutrition can actually help the intestinal wall heal faster and speed up recovery times. Paste like food can be administered via a nasogastric tube. This tube allows vet staff to syringe food directly into the pets stomach, bypassing the need for them to want to eat it.
- Provide electrolytes. Pets that are vomiting and having diarrhoea often lose a lot of electrolytes. Some of these are vital for normal body functions. In these cases, vets will administer IV electrolytes, such as potassium and glucose.
- Giving TLC. Even though these puppies have to be kept in isolation, they still thrive on TLC (who doesn’t when they are sick?). Regular pats and comforting sick pets goes a long way to improving the rate of success in our view. Many vets will also allow owners to visit but usually they need to wear gowns, gloves and other protective equipment to do so.
This intensive veterinary care, with constant intravenous fluids, and a cocktail of medications given 4-6 times a day for 7-10 days, gives the best chance of survival for a dog from parvovirus. However, due to the high cost of providing this care it is not abnormal for parvovirus treatment costs to range from $1,500 to $10,000+.
Why such a big range? It all depends on how sick your dog becomes, how quickly they respond to treatment, how many days of hospitalisation they require and if they need intensive measures such as blood and plasma transfusions to keep them alive.
Parvovirus Outpatient Protocol
In light of this, a parvovirus outpatient protocol has been developed by Colorado State University. Basically this protocol includes an initial stay at the vet hospital followed by intensive at home care.
The at home care still includes a home visit by the vet for a once daily physical examination, testing and administration of medications. So whilst this protocol can result in some cost savings (if successful), it still bears a considerable expense.
The initial vet hospitalisation in the protocol is aimed at cardiovascular support by resuscitating pets with an initial course of IV fluids. The second aim is to rapidly restore proper electrolyte and blood glucose balance by IV injection. Finally the long acting antibiotic Cefovicin (brand name Convenia) is injected prior to discharge.
Outpatient care at home follows and is not for the faint hearted. It involves the administration of subcutaneous (under the skin) fluids daily and constant monitoring of vital signs by the dog owner.
A daily injection of the an anti-vomiting medication, Maropitant (brand name Cerenia) is given by the veterinarian. Pain relief is provided when pets are showing continued signs of visceral pain (about 20% of cases). Blood glucose and electrolyte status are assessed by the veterinarian and supplementation given when needed to bring levels back into a normal range.
The outpatient protocol is not as successful as in the intensive vet treatment protocol in clinic. Pets that fail to respond properly to the outpatient protocol will need to revert to the traditional in clinic method.
Signs that the outpatient method is not working:
- continued dehydration, where subcutaneous fluids are not sufficient to correct deficits
- elevated lactose in the blood
- decline in mentation
- continued fever
- other factors that prompt the transition, based on the attending vets discretion
Parvovirus Survival Rate
According to studies, untreated canine parvovirus has a high morbidity (illness) rate of 100%, and high mortality (death) rates of 91% in puppies and 10% in adult dogs.
However, the good news is that according to the AVMA, the survival rates for pets that receive proper veterinary parvovirus treatment can be as high as 90%.
So your dog survived parvo, now what? By now they will likely be at home happily eating and getting around as normal. But did you know that they could still be contagious to other pets? In fact the environment where they live (your house or yard) may also still be severely contaminated with virus particles.
We’ve already seen above that a single ounce of “parvo poop” can carry 35 million virus particles (equivalent to enough particles to infect 35,000 dogs). Imagine then how many virus particles are in your yard in total.
While this doesn’t pose a risk to your recently recovered pet, it can be a risk to other pets that visit your house or from you transferring the virus on your hands, clothing or shoes.
The parovirus lifespan is usually limited to around 1 month for indoor areas and up to 7 months for shaded outdoor areas.
It is not uncommon for someone who has had an infected dog to get a new puppy months later who then contracts the same disease from their yard.
For this reason, cleansing your environment with a suitable parvovirus disinfectant is of vital importance.
The recent coronavirus pandemic has highlighted to everyone how contagious some viral diseases can be, and canine parvovirus is no different.
To decontaminate your home environment from parvovirus you can use a number of different disinfectant solutions. But first, its important to pick up and dispose of any faeces promptly.
Disinfectants like Dettol, Clorox, Lysol, Odoban and Alcohol will NOT kill parvovirus.
What works? Good old hospital grade bleach.
A bleach solution containing 1 part hospital grade bleach to 30 parts water is suitable as a household disinfectant for parvovirus. On hard surfaces it is important to leave the bleach solution on the surface for at least 15 minutes.
For surfaces that would be damaged by the application of bleach, an anti-viral solution can be used. Your vet should be able to supply you with something for the task. A popular choice is a product called F10SC.
High heat will kill parvovirus but it has to be temperatures of around 120-130 degrees Celsius for a period of 15 minutes.
Sunlight can also deactivate the virus. Putting pet bedding, clothing, food bowls etc in the hot sun for 24 hours can assist in killing the virus.
The hardest part is the treatment of the yard. Shady areas are the worst for prolonging the survival of the virus. If possible, open up the yard area and expose it to as much sunlight as possible. Raking and turning over the soil can help to expose new layers to the sun.
Rain and watering can also help to dilute the concentration of the virus over time. It may even pay to section these areas off if possible, with a fence or barrier.
In spite of these efforts, shaded areas should be considered contaminated for seven months.
For this reason it’s important that other unvaccinated dogs don’t enter your property for anywhere up to 1 year after a viral infection.
Ensure all puppies that come to your property have been fully vaccinated and allow 2 weeks after their final vaccination before entry.
This is why boarding kennels and similar places are so strict on checking a pet’s vaccination status prior to boarding.
Dog vaccinations are extremely effective in preventing your pet from contracting parvovirus. However, the correct parvo vaccination schedule is needed to provide proper protection.
Whilst your dog is receiving their initial parvo vaccination series, it is important to keep them isolated from other environments or from contact with unvaccinated pets.
Is the parvovirus vaccine 100% effective? No. Very rarely you can get a puppy who is classified as a “poor responder”. For one reason or another the vaccine does not trigger the immune response required to generate future protection. But these cases are extremely rare.
Parvo Vaccine Names
Your pet has been vaccinated for parvovirus if they have received a C3, C4 or C5 vaccination. These vaccinations also protect against a number of other diseases such as kennel cough in dogs.
Parvo vaccine names in Australia include:
- Protech by Boehringer Inglheim
- Duramune by Boehringer Ingelheim
- Nobivac by MSD
- Companion by MSD
- Canigen by Virbac
Vaccination schedules will vary depending on the brand of vaccine your vet uses and the manufacturers recommended protocol based on lab data. However, generally speaking, most puppy vaccination schedules follow a series of three injections at either 6 weeks, 8 weeks and then 10 weeks, or alternatively, 8 weeks, 12 weeks and 16 weeks. Puppy vaccinations are then followed by yearly booster vaccinations as adult dogs.
For unvaccinated adult dogs, a series of one or two booster vaccinations given 2-4 weeks apart is usually enough to provide adequate protection. These are then given yearly or every three years depending on the vaccine.
In puppies entering high risk situations, such as when an infected dog has been in the house before, additional vaccinations may be recommended. These can sometimes include vaccinations earlier than 6 weeks of age.
Check with your vet about the specific timing and protocols they use.
In place of the yearly vaccination boosters, titre testing can also be used. A titre is a blood test that measures the amount of antibody still in your pet’s blood stream from either a previous vaccination or from a parvovirus episode. If the level is sufficient then repeat vaccination can be postponed.
Parvo Vaccination Cost
Parvo vaccination costs will vary, again, depending on the brand of vaccine your vet uses, whether its a house call service or a clinic visit, and the individual vet’s pricing structure.
In Australia, parvovirus vaccinations usually cost between $80 – $150.
Considering that if your pet contracts the disease, parvovirus treatment costs can be anywhere from $1,500 to $10,000+, the small cost of a vaccine is a worthwhile investment in your pet’s health.
Apart from anything, parvovirus is a horrible disease for a dog to go through. The success of treatment is not 100%. So make sure you get your puppy vaccinated and keep their vaccination up to date.
How a mobile vet can help
A mobile vet service is an ideal solution when it comes to both preventing parvovirus in your pets, by administering vaccinations, as well as treatment services like the parovovirus outpatient protocol highlighted above.
What better use of a mobile vet service than to come to your home and provide personalised care for your sick pet in the comfort of your own home.
Most frequent questions and answers about Parvovirus in dogs.
Typically 4-6 weeks after recovery.
Yes. Whilst puppies are the most commonly affected, unvaccinated adult dogs can still contract parvo virus.
Techinically yes. In reality, it’s unlikley. Antibodies to the first bout of parvovirus typically will last for several years. If these antibody levels wane in later years then reinfection is possible. This is why it is still essential to keep your pet’s vaccinations up to date once they have recovered. Either that, or titre test.
The other factor to consider is that parvo is a virus which comes in a number of different strains which can also mutate over time. These may have the ability to affect a dog already recovered from parvovirus with another strain.
Yes, with proper and prompt veterinary care a pet has up to a 90% chance of survival from parvovirus. Without this treatment, the survival rate is only 5-10%.
Whilst it is unlikely, it is still technically possible for a number of reasons:
- a small number of pets have immune systems that do not respond as expected to a vaccination (also called poor responders), leaving them vulnerable to the disease.
- like most viruses (e.g influenza virus in people), parvo has the potential to mutate into new strains. This means vaccination may not protect against all strains of the virus.
Firstly, a vaccine isn’t like a drug that works instantly. It takes time for your pet’s body to develop the antibodies it needs to protect again the real virus. This is usually between 1-2 weeks after vaccination.
Secondly, it also depends on the age of your pet at the time of vaccination and the type of vaccine used by your vet. Most vets recommend waiting until after a third puppy vaccination before taking your pet out of your yard into unfamiliar and uncontrolled environments.
Puppies being treated for parvo still look very sick up until around 5-7 days after treatment. Then it’s as if someone hit the switch and they usually become boisterous, barking and willingly accept food that is offered by hand. Up until this point it is very much touch and go.
Generally if your pets mentation and alertness continue to improve from day to day, that is a positive sign that a full recovery is on the way.
No. Cats have their own version of parvovirus, more commonly known in Australia as panleukopenia virus. However these viruses stay within their own species.
No. Each species has their own version of parvovirus that isn’t transmissible to one another. B19 infects humans, which doesn’t affect dogs and vice versa.
Yes. Any member of the canine family can contract and spread parvovirus. This includes foxes, dingos and wolves etc.
No, not in Australia. Parvovirus is already endemic in many parts of the country.