Yesterday morning, I walked into an exam room to see my next patient and commented on the pup’s beautiful blue eyes. His little girl jumped up and said “I have blue eyes, too! We ordered our puppy from Amazon.” I couldn’t help but chuckle. They had actually bought the dog from a breeder in another state. Sadly after a few days with his new family, he developed bloody diarrhea. Now he was in the clinic to get a parvo test.
In the late 1970s and early 1980s, canine parvovirus became a serious issue in the United States. The virus is now a leading source of death and sickness in dogs throughout the world. We’ve come a long way in our capacity to prevent and treat the disease but can a puppy survive parvo without treatment?
Only about 10% of puppies with parvo survive without treatment. In other words, 9 out of 10 untreated parvo puppies die. Compare that to an 80-90% chance of survival for in-patient parvo infected puppies. Even puppies treated for parvo as outpatients have a 75-80% survival rate. (8, 5)
What Is Dog Parvo?
Canine parvovirus (CPV) is a highly infectious virus that causes severe vomiting and diarrhea in dogs. CPV spreads readily via the body fluids of an infected dog. The primary route of transmission is by oral exposure but the virus can also spread by respiratory exposure.
For example, if an unvaccinated puppy walks over grass that a dog with parvo pooped on, the virus might stick to their feet. Then when the pup licks his foot, he unknowingly eats some parvo virus.
Parvovirus multiplies and destroys intestinal cells, causing major digestive abnormalities. This leads to vomiting, diarrhea and the inability to eat and drink. Between the fluid losses and lack of fluid/electrolyte replenishment, dehydration sets in quickly and can lead to death.
Another major problem is that the inflamed intestines allow “bad” bacteria to get into the bloodstream, causing secondary infections.
Do Worms Cause Parvo?
Intestinal parasites (like hookworms and roundworms) do not cause parvo in dogs. However, it may make a dog more susceptible to parvo infection or make their parvo symptoms worse. (4)
Running a parvo test is the best way to determine if a dog’s diarrhea is caused by parvoviral enteritis or worms. A negative parvo test means parasites may be causing your pup’s symptoms. Your vet can run a fecal test for parasites to check for worms, coccidia and giardia.
Your vet will probably want to run both tests if your puppy is sick. It’s important to give the right antiparasite drugs to a dog who has parvo so they’re not dealing with two problems.
Symptoms of Parvo in Puppies & Dogs
Lethargy, unwillingness to eat, vomiting, and diarrhea (with or without blood) are typical canine parvo symptoms. Just remember, the absence of any of these symptoms does not rule out the possibility of parvo.
Many of my clients mistakenly believe that if their dog does not have bloody diarrhea, it does not have parvo. That is not the case; puppies with bloody stool may or may not have parvo, as may puppies without bloody stool.
The best way to diagnose parvo is with a test your vet can run that identifies viral antigens in the feces. Your vet will collect a tiny sample of fresh fecal matter and the test takes 10 minutes to yield a positive or negative result. The accuracy of these tests is not 100% perfect but is still very good.
Watch for These Stages of Parvo
Stage 1: Exposure & Infection from Virus Particles
Parvovirus particles are passed in the feces and body fluids of an infected dog. Virus particles can remain infectious on surfaces for weeks to months. Exposure occurs when a dog licks or inhales virus particles. A dog with good immunity from previous exposure or vaccination will mount an immune response to fight off the virus.
Stage 2: Multiplication of Virus in Dog’s Body
In the first 1-5 days after entering the body, the virus multiplies in the lymph nodes and is carried in the blood to all parts of the dog’s body.
Stage 3: Cell Destruction, Immune Response & First Symptoms of Parvo
Within 7-14 days of infection, parvovirus invades rapidly dividing cells in the intestine of dogs without good immunity to parvovirus. The virus causes massive damage to these cells and leads to most of the symptoms seen in dogs with parvo. Other cells that may be affected by the virus include those in bone marrow, heart, nervous system and skin.
Stage 4: Worsening Symptoms & Secondary Problems
As intestinal cells die, symptoms get worse. Most dogs with parvo have watery diarrhea, often with blood and mucus. Vomiting and poor appetite are usually seen in this stage. A typical dog with parvo is extremely lethargic and refuses food and water.
Without the ability to replenish fluids by eating and drinking, severe dehydration and electrolyte abnormalities set in. Bad bacteria are also able to cross the damaged intestinal tissue and enter the bloodstream.
Stage 5: Recovery or Death
80-90% of treated dogs start to show signs of recovery within 5 to 7 days after the onset of symptoms. Vomiting becomes less frequent and their stool has less blood and mucus in it. We often notice parvo puppies become more energetic a day or two before full recovery. Once they regain their appetite, they often recover completely within a day or so.
90% of untreated dogs with parvo die. Death often occurs within the first 3-4 days of symptomatic illness but can occur later. (2)
Can Dogs with Parvo Eat or Drink Water?
Canine parvo is characterized by a lack of appetite or an outright refusal to eat. During the early stages of their infection, some dogs may still eat or drink a little. If your dog is eating well and is not vomiting, it’s unlikely that he has parvo.
Even if they vomit afterward, it is recommended to assist feed (a.k.a. force feed) a dog with a confirmed parvo diagnosis. Veterinarians recommend feeding an easy-to-digest, high-calorie diet.
Nutrients aid in the healing of injured intestinal cells, thus even a small amount of retained food can be beneficial. Standard treatment for parvo puppies is syringe-feeding canned puppy food gruel every several hours while they’re hospitalized.
Canine Parvovirus Treatment Options
Treatment in Hospital
The best chance of survival for parvo-infected dogs is hospitalization. Supportive care, including intravenous fluids, anti-nausea medication, antibiotics, and aided feeding, is the basis of treatment. Hospitalized pups have a survival rate of 80-90%.
The cost of in-patient parvo treatment is the biggest obstacle to providing high-quality care. The bill is often in the range of $1000 per day and up, and there is no assurance of survival.
Home Treatment of Parvo With a Vet’s Help
In the last ten years, veterinarians have discovered that outpatient treatment of canine parvo helps 75-80% of infected dogs survive.
Although treatment approaches differ, they all revolve around the same principles that are used to treat hospitalized puppies: hydration, vomiting prevention, antibiotics to manage subsequent bacterial infection, and assisted feeding.
Dog owners play a significant role in delivering these treatments at home. Outpatient parvo treatment costs vary depending on how sick the dog is and how long the symptoms linger, but they can range from a few hundred dollars to thousands of dollars by the time the full course is finished.
Parvo Home Treatment Without a Vet
Without the assistance of a veterinarian, a sick pup’s chances of survival are predicted to be substantially lower, possibly as low as 10%. Puppies with parvo can’t hold any food or liquid down due to vomiting, and they lose even more fluids due to severe diarrhea.
Clients have told me they were able to save the life of a parvo puppy by simply force-feeding electrolyte-replenishment drinks to it. Although older, larger puppies have some chance of beating parvo without much medical care, I would not advise anyone to take this route!
Even just administering subcutaneous fluids can boost survival odds without costing a fortune.
How Long Does Parvo Last?
The symptomatic phase of canine parvo infection usually lasts 5 to 7 days. (4) Some dogs recover in a shorter period of time, while others show symptoms for up to 14 days.
How Long Does It Take Parvo to Kill a Dog?
Puppies are more likely to die within the first few days of developing parvo symptoms. But even if they seem to be doing well, a few will die many days later. Younger, smaller puppies are more likely to die from parvo.
According to one report from a major animal shelter, 80% of parvo deaths occur during the first five days of diagnosis. Puppies who made it through the first five days had a 96.7% chance of recovering from a parvovirus infection.(6)
How Do I Know if My Puppy Will Survive Parvo?
Playing the odds, you can get some idea of whether or not your dog will survive parvo. Factors that increase survival include:
- Fluid replacement therapy
- Anti-nausea medication
- Antimicrobial therapy
- Early nutritional therapy (7)
Your vet can get a better idea of prognosis by running blood tests. Research shows that dogs with a low white blood cell count at the beginning of their illness were less likely to survive. (2)
Preventing Canine Parvovirus Infection
Vaccination with the proper vaccine at the appropriate time is the most effective strategy to prevent your dog from contracting parvovirus. If you administer a vaccine too soon or store it incorrectly, your dog’s immune system may not develop a strong enough response to protect him from the virus.
Another crucial part of preventing CPV infection is avoidance. This is particularly true for puppies under the age of five months. This is because they still have their mother’s parvovirus antibodies in their system. These maternal antibodies neutralize the vaccine antigen before the puppy can mount their own immune response.
Maternal protection from parvovirus wanes before a pup reaches the age of five months, but we don’t know when. That’s why we give your pup multiple parvo vaccine doses, one of which will occur just when the maternal antibodies are wearing off, allowing a pup to mount their own CPV protection.
It is critical to keep an unvaccinated puppy safe from parvo. I advise my clients not to take their puppies out in public for at least a week after their final puppy immunization, which is given at 16-20 weeks of age.
Public places include any location that another dog could have visited in the last few months. Parvovirus can survive for months on the ground. So just because you don’t see any dogs doesn’t imply there isn’t parvo in the region. If you must take your puppy to a public place, such as a pet store, keep them in your arms and don’t let them run around on the floor!
Without medical therapy, the survival rate for puppies afflicted with parvo is roughly 10%. A few puppies may survive parvo with only home administration of oral fluids but chances of survival are only slightly higher than dogs who receive no therapy at all.
Aggressive in-patient treatment gives dogs sick from parvovirus the best chance for a positive outcome but might be too expensive for some owners. Outpatient treatment under the care of a vet also gives sick pups a good chance of survival at a fraction of the cost of hospitalization.
- Bragg, R. F., Duffy, A. L., DeCecco, F. A., Chung, D. K., Green, M. T., Veir, J. K., & Dow, S. W. (2012). Clinical evaluation of a single dose of immune plasma for treatment of canine parvovirus infection. Journal of the American Veterinary Medical Association, 240(6), 700-704.
- Goddard, A., Leisewitz, A. L., Christopher, M. M., Duncan, N. M., & Becker, P. J. (2008). Prognostic usefulness of blood leukocyte changes in canine parvoviral enteritis. Journal of Veterinary Internal Medicine, 22(2), 309-316.
- Greene CE, Decaro N: Canine Viral Enteritis. Infectious Diseases of the Dog and Cat, 4th ed. Elsevier 2012 pp. 67-75.
- Horecka, K., Porter, S., Amirian, E. S., & Jefferson, E. (2020). A decade of treatment of canine parvovirus in an animal shelter: A retrospective study. Animals, 10(6), 939.
- Mylonakis, M. E., Kalli, I., & Rallis, T. S. (2016). Canine parvoviral enteritis: an update on the clinical diagnosis, treatment, and prevention. Veterinary Medicine: Research and Reports, 7, 91.
- Prittie, J. (2004). Canine parvoviral enteritis: a review of diagnosis, management, and prevention. Journal of Veterinary Emergency and Critical Care, 14(3), 167-176.
- Sarpong, K. J., Lukowski, J. M., & Knapp, C. G. (2017). Evaluation of mortality rate and predictors of outcome in dogs receiving outpatient treatment for parvoviral enteritis. Journal of the American Veterinary Medical Association, 251(9), 1035-1041.
- Sullivan, L. A. (2016). In Veterinary Emergency and Critical Care 2016 Spring Symposium. Cabo San Lucas; Veterinary Emergency and Critical Care Society. Retrieved January 28, 2022, from https://www.vin.com/members/cms/project/defaultadv1.aspx?id=7244566&pid=14212&.