What Is Parvo in Dogs?

Parvo or CPV (Canine Parvovirus) is a common and fatal disease among puppies and unvaccinated dogs. As responsible pet owners, it’s crucial that you know the consequences of this disease so you’ll know what to do. This article explains what parvo is in dogs, including the causes, signs, and treatment.

What Is Parvo in Dogs?

Canine parvovirus is a highly infectious and deadly virus transmitted through direct contact with infected dogs or contaminated objects. Parvovirus damages a dog’s gastrointestinal tract, myocardium or heart muscle in some cases and the immune system or white blood cells. The virus can destroy cells, impair the gut barrier (gastrointestinal tract), and reduce a dog’s ability to fight bacterial infections.

A puppy with a brown coat lying on a white and orange blanket

It’s a prevalent virus among unvaccinated puppies and even poorly-vaccinated adolescent dogs. Understanding what parvo is, especially the symptoms leads to understanding and effective prevention.

How Does a Dog Get Parvovirus?

Dogs contract parvovirus through direct or indirect contact with an infected dog, objects such as toys, water bowls or even the ground outside where another dog has contaminated the soil. The virus can also survive in the environment, especially on human clothes, your bedding, or even the grass at dog parks.

Puppies around six weeks to six months old are the most susceptible to the virus because they have not received complete vaccination protecting them from the virus. They are remain vulnerable to parvovirus until they complete their vaccination against it and there has been enough time for the antibodies to reach protective levels in their body. 

The canine parvovirus first emerged among dogs and wildlife in Europe around the 1970s. The virus spread unchecked, causing a worldwide epidemic. Decades after, the virus continues to target puppies and cause outbreaks.

What Happens When a Dog Has Parvo?

Parvovirus is a highly transmissible disease that targets a dog’s immune system. The attack happens within days due to a series of infections.

Attack on the Cells

There’s a three to seven-day incubation period before the onset of the first symptoms. The virus needs rapidly dividing cells to spread. First, the virus attacks the gastrointestinal tract, bone marrow and lymph nodes. Next the virus usually attacks the tonsils and lymph nodes of the throat. Parvovirus hides in the white blood cells from the immune system and replicates often, increasing its viral numbers. Ultimately, if these infected cells or lymphocytes are destroyed, the overall number of these cells decreases in the bloodstream. This is known as lymphopenia. This is one way the virus effectively causes a patient to become immune compromised- because there are less white blood cells or lymphocytes fighting infection. 

When there’s a drop in the protective white blood cell count, the virus can easily invade rapidly dividing cells such as those lining the small intestine, bone marrow and heart. In the bone marrow, the virus destroys young immune cells causing the protective white blood cell count to drop even further. Next, the virus is able to invade the gastrointestinal tract and cause damage to the small intestine. The small intestine typically absorbs nutrients and prevents bacteria from entering into the bloodstream. The virus invades the cells lining the intestines damaging the cells. As a result severe diarrhea and nausea occur as the intestinal surface breaks down. In addition, with a weakened immune system, a dog’s body will struggle to produce new white blood cells to combat the infection. In turn, bacteria are able to penetrate the intestine into the bloodstream causing widespread infection or sepsis.

Oftentimes, this cascade of events is fatal: Massive dehydration, electrolyte imbalances and low blood sugar otherwise known as hypoglycemia caused by sepsis or infection in the bloodstream. The virus may also attack the heart muscle causing myocarditis. Weak heart contractions and arrhythmias may lead to death.  

What Are the Signs of Canine Parvovirus?

Dogs with parvo virus infection may become very sick with severe dehydration. Bring your dog to the veterinarian right away if you notice more than one of these symptoms:

  • Vomiting
  • Abdominal pain and bloating
  • Dehydration
  • Fever
  • Bloody diarrhea
  • Loss of appetite
  • Lethargy

Those with severe cases may have a high heart rate, difficulty breathing, a drop in body temperature, or even seizures in pets.

A pure bred dog sitting with the staff

What Is the Treatment for Dogs With Parvovirus?

Dogs may be able to survive parvovirus if treated immediately by a Veterinarian. However, this may depend on the severity of the case.

There’s a 68% to 92% survival rate among dogs treated for parvovirus. This depends on immediate treatment. Typically treatment is necessary between 48 to 72 hours from the onset of symptoms.

There’s no drug or prescription that kills the virus. Veterinarians provide supportive care to correct dehydration, electrolyte imbalances and prevent hypoglycemia (low blood sugar). Typically antibiotics are given to prevent bacteria infection in the bloodstream (sepsis). 

Dogs infected with Canine Parvovirus have severe vomiting and diarrhea. With this, there is significant dehydration and fluid loss. An intravenous catheter is placed to replace fluids directly into the bloodstream. Perhaps, this is the most important and effective treatment for the virus. Unfortunately, IV (Intravenous fluids) is only possible with hospitalization. Fluids under the skin (subcutaneous fluids) may be helpful in very mild cases but usually are not able to effectively replace the dramatic fluid loss.

Treatment is also targeted against controlling the vomiting and diarrhea with medications. Often these medications must be given as an IV treatment because a patient is not able to absorb medications from the intestine. Some patients may need a plasma transfusion. 

These patients are usually not a candidate  for hospice care. Hospitalization is recommended rather than home palliative care. 

Your vet may recommend keeping your dog hospitalized for at least three days for proper monitoring. It’s not advisable to bring your dog home right away, especially if you have other pets at risk of getting infected.

How to Prevent Parvovirus in Dogs

Parvovirus can be fatal, yet it’s also preventable. These are simple and proven ways to prevent your dog from contracting parvovirus.

  • Get your puppies vaccinated against canine parvovirus starting at 8 weeks of age every month until 16 weeks of age. Continue with booster shots afterwards.
  • Ensure the breastfeeding mother has complete vaccination as well since puppies will rely on the mother’s antibodies for the first few weeks.
  • Limit your dog’s interaction with other pets until vaccination is completed.
  • Clean and sanitize your dog’s living spaces.

A white French bulldog wearing a blue and white scarf while seated on a stainless steel

Related Questions

How Long Are Dogs With Parvo Contagious?

Dogs with parvovirus may shed the virus within five to 10 days of treatment and recovery, so they remain contagious around this stage. However, the virus can survive indoors for at least one month, so cleaning and disinfecting your surroundings is crucial.

What Are the Signs That My Dog Is Recovering From Parvovirus?

If your dog has stopped vomiting and there’s no blood in the feces, this means your dog is recovering from parvo. Other signs of recovery include eating habits and energy levels returning to normal.

Can a Dog Get Parvo Twice?

While not downright impossible, it’s unlikely that a dog will get canine parvovirus again, especially if it has been vaccinated. You must continue routine vaccinations to lower the risk.

Conclusion

Parvovirus is an infectious disease common among young and unvaccinated dogs. Canine parvovirus targets a dog’s cells, intestinal tract, and bone marrow, causing death if left untreated. Paws Into Grace provides in-home euthanasia and San Diego cremation services for pets to have a peaceful and dignified passing.

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