Parvo in Dogs: What To Know About Canine Parvovirus

Canine parvovirus (CPV), commonly called “parvo,” is a severe virus that poses a significant threat to dog health. Since its discovery in the 1970s, it has spread rapidly and remains a serious concern. This virus is difficult to eliminate, survives long in the environment, and spreads easily through contact with infected dogs.

The parvo vaccine has greatly reduced the risk for many, yet the virus is still prevalent among puppies and poorly vaccinated adolescent dogs. Understanding how to protect dogs, recognize symptoms, and respond if a dog falls ill is crucial for all dog owners.

What is Parvo in Dogs?

Canine parvovirus is a contagious DNA virus that often leads to serious illness in young and unvaccinated dogs. It mainly targets cells that divide quickly, such as those in the intestinal tract and bone marrow. In very young puppies, it can also damage heart muscle cells.

Although parvovirus mostly affects puppies and young dogs, it can also infect grown or older dogs, especially if they haven’t been vaccinated.

How Do Dogs Get Parvo?

Parvovirus spreads when dogs come into contact with contaminated faeces. The virus can be present even if the faeces are not visible. Some of the places that can harbour the virus include:

• The ground
• Kennels
• People’s hands
• Objects
• Clothing

Dogs can also carry the virus on their fur or paws if they touch something contaminated. The virus is very contagious and can spread quickly among dogs. It can survive in the environment for months or even years. It is resistant to many disinfectants but can be killed by diluted bleach and some specialised cleaners used in veterinary settings.

Can Humans Get Parvo?

Parvovirus is species-specific, so dogs and humans get different versions of the virus. This means that humans cannot catch parvovirus from dogs, and dogs cannot catch parvovirus from humans.

It is still important to be cautious around infected dogs. Wearing personal protective equipment can help prevent the virus from being spread to other dogs via hands or clothing.

Diagnosing Parvovirus in Dogs and Available Tests

Diagnosing parvovirus in dogs often involves the Fecal SNAP ELISA test, also known as the Parvo SNAP test. This test requires a fecal swab and takes around 10 minutes to complete.

Even though the test is accurate, a negative result does not fully rule out parvovirus if the dog shows symptoms. The dog may not be shedding the virus at the time of testing. More tests might be necessary in such cases.

Predisposed Breeds and Ages

Young puppies, especially those between 6 weeks to 6 months old, are at the highest risk of contracting and suffering from parvovirus. Their immune systems are still developing, making them more vulnerable to the virus.

Certain breeds seem to be more susceptible to parvovirus. These include:

• Rottweilers
• Doberman Pinschers
• American Pit Bull Terriers
• German Shepherds

Unvaccinated dogs and those with weak immune systems are also at higher risk. Proper vaccination and regular vet check-ups are crucial in reducing the likelihood of infection.

Transmission and Risk Factors

Canine parvovirus spreads easily, posing serious risks to dogs, especially puppies. Knowing how the virus transmits and which dogs are more at risk can help in preventing the disease.

Canine parvovirus is mainly transmitted through direct contact with an infected dog or contaminated objects like food bowls, leashes, or even people’s clothing. The virus can also survive in the environment for months, making indirect transmission possible.

Faeces from infected dogs contain large amounts of the virus. When a healthy dog sniffs or consumes infected faeces, the risk of contracting the virus is high. Due to the high dog traffic, community areas like dog parks can be hotspots for transmission.

Phases of Parvo in Dogs

1. Initial Contact

Dogs can contract parvovirus by coming into contact with faecal material from an infected dog. Even if the material isn’t visible, the virus can be spread through contaminated surfaces and objects.

2. Latency Period

The virus has a latency period of three to seven days. During this time, the dog carries the virus but doesn’t show signs. The virus attacks fast-dividing cells like those in the tonsils or lymph nodes first. After spreading to the bloodstream, it targets more rapidly dividing cells, like bone marrow and cells lining the small intestines.

The virus may reach the heart in very young puppies, causing inflammation, poor function, and irregular heartbeats.

3. Symptoms Manifest

When parvovirus reaches the bone marrow, it attacks immature immune cells, reducing the dog’s white blood cells. This weakens their immune system, making it easier for the virus to invade the gastrointestinal (GI) tract. The virus damages the intestinal lining, preventing the dog from:

• Absorbing nutrients
• Keeping fluid from leaking into the stool
• Stopping bacteria from entering the bloodstream

These issues can lead to severe health complications. While not always fatal, dogs that don’t survive typically die from dehydration or shock, along with bacterial infections from the intestines entering the bloodstream.

Diagnosis of Canine Parvovirus

Diagnosing Canine Parvovirus involves specific tests and procedures that identify the virus. It also requires distinguishing parvo from other illnesses with similar symptoms.

Laboratory Tests and Procedures

Veterinarians use several tests to diagnose Canine Parvovirus.

ELISA Test

The Enzyme-Linked Immunosorbent Assay (ELISA) is a common test. A faecal sample detects the virus. Results come within minutes, but false positives or negatives are possible.

PCR Test

The Polymerase Chain Reaction (PCR) test is more accurate. It identifies viral DNA in the faeces and can spot even small amounts of the virus. This test takes longer than ELISA but provides a precise diagnosis.

Blood Tests

Complete Blood Count (CBC) checks for low white blood cell counts, which indicate infection. Low counts are typical in parvo cases. Biochemical panels assess organ function, helping identify dehydration and electrolyte imbalances. Fast and accurate diagnosis is vital to begin treatment promptly.

Differential Diagnosis

Parvo symptoms resemble other diseases, making differential diagnosis essential.

Distemper

Canine distemper causes fever, vomiting, and diarrhoea, similar to parvo. Distemper also affects the respiratory system, which is not typical in parvo.

Giardiasis

This parasitic infection leads to diarrhoea and dehydration like parvo. A faecal test confirms the presence of Giardia cysts instead of the parvovirus.

Intestinal Blockages

Blockages cause vomiting and lethargy. X-rays or ultrasounds help distinguish blockages from parvo.

Salmonella

This bacterial infection causes symptoms such as vomiting and diarrhoea. Culturing the bacteria from a faecal sample can confirm Salmonella infection.

Differential diagnosis ensures the dog receives the right treatment for its specific condition.

Parvo Treatment in Dogs

There is no specific cure for parvovirus in dogs, so treatment focuses on helping the puppy’s body fight the virus. Supportive care usually includes hospitalisation with intravenous fluids and antiemetics to stop vomiting. Nutrition is important and sometimes requires a feeding tube. Electrolyte imbalances or low blood sugar levels may need correction.

Some veterinarians might recommend a canine parvo monoclonal antibody (CPMA) treatment. Puppies showing signs of sepsis, where bacteria from the intestines enter the bloodstream, often need antibiotic therapy. Antibiotics may also be given to puppies with high fever or low white blood cell count.

The highest risk of death occurs 24–72 hours after symptoms appear. With hospitalisation and close monitoring, the survival rate is around 85–90%.

Understanding the Incubation Period of Parvovirus

Dogs exposed to parvovirus generally have an incubation period of three to seven days. During this period, they might start to shed the virus a few days before showing any symptoms.

Treatment for dogs infected with parvo often involves hospitalisation for five to seven days, but they might remain ill for a longer period.

Most dogs are considered recovered and non-infectious about 14 days after the first symptoms appear. In some cases, this period can extend to 21 days.

Additionally, the parvovirus can persist in the environment for months or even years after being shed by an infected dog.

Are There Home Remedies for Parvo?

There are no home remedies for parvo in dogs. Treatment at home is sometimes tried if the dog is not very sick or if veterinary care is too costly.

Outpatient Treatment for Parvo:

• Subcutaneous Fluids: Fluids given under the skin to keep the dog hydrated
• Special Diet: Highly digestible diets to ease digestion
• Antiemetics: Medicines to prevent vomiting
• Antidiarrheals: Medicines to control diarrhoea
• Antibiotics: To prevent secondary infections

Though some dogs may recover with this method, hospitalisation is much safer and more effective.

How To Prevent Your Dog From Getting Parvo

Vaccination Schedule

Puppies should receive a combination vaccine such as DHPP, DAPP, or DHLPP. This should be administered every two to four weeks starting from six to eight weeks of age until they are 16 to 20 weeks old.

Timely Vaccinations

Sticking to this schedule is crucial, as missing or delaying vaccinations can leave your puppy vulnerable during a critical period when their maternal antibodies fade.

Socialization

Socialization is equally important but must be handled with care. Until your puppy is fully vaccinated, limit their interactions to fully vaccinated dogs in safe environments. Avoid high-risk areas such as dog parks or public spaces where they may encounter unvaccinated dogs or contaminated surfaces.

Instead, consider arranging playdates with trusted dogs who are up to date on their vaccinations. Controlled socialization not only protects against disease but also aids in your puppy’s behavioral development.

Booster Shots

Vaccination doesn’t end after the initial puppy stage. A booster vaccine is essential at one year of age to reinforce immunity, followed by regular boosters every one to three years throughout your dog’s life. For those concerned about over-vaccination, parvovirus antibody tests can be used to monitor immunity levels. These tests provide an alternative way to ensure your dog remains protected without unnecessary vaccinations.

Monitoring

For those concerned about over-vaccination, parvovirus antibody tests can be used to monitor immunity levels. These tests provide an alternative way to ensure your dog remains protected without unnecessary vaccinations.

In summary, preventing parvovirus involves adhering to the puppy vaccination schedule, avoiding contact with unvaccinated dogs, ensuring timely booster shots, and considering antibody tests for ongoing immunity checks. By following these steps, you can safeguard your dog from this highly contagious and potentially deadly disease.

Impact on Public Health

Canine Parvovirus (CPV) can have indirect effects on public health, particularly in communities with high rates of pet ownership. It poses no direct risk to humans but can impact public health indirectly through community health strategies.

Zoonotic Potential

Canine Parvovirus does not infect humans. It is not considered zoonotic, meaning it does not transfer from animals to humans. The virus strictly affects dogs and some other animals like foxes and wolves.

Still, responsible pet care is crucial. Pet owners should be aware of the symptoms and take preventive measures. Infected dogs can shed the virus in their faeces, contaminating the environment.

Cleaning and sanitation are essential to prevent an outbreak. Public awareness and pet vaccination play a significant role in controlling the spread of the virus.

Community Health Strategies

To manage CPV, communities often implement vaccination programs. Vaccinating dogs can help prevent the virus from spreading and becoming a larger public health issue.

Animal shelters and clinics may offer low-cost or free vaccines. Public education campaigns about the importance of vaccination are also effective.

Proper disposal of dog waste and promoting cleanliness in public spaces, like parks, can reduce environmental contamination. Signage in public areas reminding pet owners to clean up after their dogs can also be beneficial.

Finally, cooperation between veterinarians, local authorities, and pet owners is critical. Working together ensures a healthier community for both pets and people.

Supporting Research and Ongoing Studies

Research on parvovirus in dogs has made significant strides. There are new treatments and promising vaccine developments.

Recent Advances in Treatment

Monoclonal antibodies have been explored as a treatment option. These are lab-made proteins that mimic the immune system’s ability to fight the virus. In some studies, they have shown promise in reducing the severity and duration of symptoms in infected dogs.

Antiviral drugs are also being tested. These drugs aim to directly combat the virus, helping to lower its concentration in the dog’s body. Some new medications have shown potential, but more studies are needed to confirm their efficacy and safety.

Supportive care protocols have evolved too. Fluid therapy, anti-nausea medications, and nutritional support remain critical. Enhanced protocols have improved survival rates and recovery times for infected dogs.

Future Directions in Vaccine Development

Next-generation vaccines are being researched to offer broader protection. Current vaccines are effective, but scientists are looking at ways to improve them. This includes making them longer-lasting and more efficient against different strains of the virus.

DNA vaccines represent a new frontier. These vaccines use a small piece of the virus’s DNA to stimulate an immune response without causing the disease. Early tests indicate they could be more effective and easier to produce than traditional vaccines.

Therapeutic vaccines are being considered as well. These are given after a dog has been exposed to the virus, aiming to boost the immune system’s fight against the disease. Though still in early stages, they could become a vital tool in managing outbreaks.

Bold and current research is making progress, providing new hope for dogs and their owners alike.

Parvo in Dogs FAQs

Can a Dog Recover from Parvo?

Dogs and puppies can be treated effectively for parvovirus. Hospitalization for intravenous fluids and medications increases their odds of survival significantly more than outpatient care.

Early Symptoms of Parvo in Puppies

A puppy may initially show signs of tiredness and lack of interest in food. This can advance to vomiting, diarrhoea (sometimes bloody), and fever. If a puppy shows any of these symptoms, they should visit a vet promptly, who will likely test for parvo and start a treatment plan.

Is it Possible for a Vaccinated Dog to Contract Parvo?

Although no vaccine offers 100% protection, the parvovirus vaccine for dogs is highly effective. It is very rare for a properly vaccinated dog to get infected with parvovirus.

Can Parvo Strike a Dog More Than Once?

Parvo immunity generally lasts for several years. Though it’s rare, it’s not entirely impossible for a dog that has previously recovered from parvo to get it again. Despite past infection, routine vaccinations are still recommended.

Can Cats Contract Parvo from Dogs?

Dogs cannot get feline parvovirus from cats, but cats can get canine parvovirus. Cats usually show milder symptoms, though there is a strain of canine parvovirus that can cause severe illness in cats. The feline parvovirus vaccine may offer some protection against canine parvovirus.

References

• Chalifoux NV, Parker SE, Cosford KL. Prognostic indicators at presentation for canine parvoviral enteritis: 322 cases (2001‐2018). Journal of Veterinary Emergency and Critical Care. 2021;31(3):402-413.
• Horecka K, Porter S, Amirian ES, Jefferson E. A Decade of Treatment of Canine Parvovirus in an Animal Shelter: A Retrospective Study. Animals. 2020;10(6):939.
• Parvovirus: Transmission to treatment. Cornell University College of Veterinary Medicine.