This viral disease is one of the most devastating puppy diseases we see.  It is usually fatal without treatment, and treatment usually consists of many days in the hospital under intensive care.  Luckily, a good vaccination exists for parvovirus.  Below is a short discussion about this devastating disease, how you can prevent it in your puppies, and what we can do if your puppy contracts parvo.

Canine parvovirus is a virus that attacks rapidly dividing cells, especially those in the intestinal tract, bone marrow, and lymph nodes.  In the intestinal tract, the virus destroys the cells that line the intestinal tract.  This leads to vomiting and diarrhea and severe dehydration because the body can no longer absorb nutrients or water.  The intestinal lining is also a protective barrier against the bacteria that normally live in the intestines.  Without it, these puppies can become septic, meaning that they have a widespread infection within the body.  In the bone marrow, the virus destroys new white blood cells, which prevents the body from fighting off the virus and other secondary infections. 

Puppies contract parvo from coming in contact with other infected dogs.  The virus is shed in the stool and is extremely hardy in the environment.  It can survive for long periods and travel on shoes, clothes, toys, food bowls, and other things that come into contact with infected stool.  There is a 3-10 day incubation period from the time that a dog gets exposed to parvo until he or she breaks with clinical signs, so parvovirus can be shed during that time without owners knowing their dog is sick. 

Any puppy exhibiting the following symptoms should be tested for parvo, especially if you have acquired the puppy within the last week or there has been exposure to other dogs:

• Inappetance
• Lethargy
• Diarrhea (with or without blood)
• Vomiting (with or without blood)

Puppies can get VERY sick VERY quickly when they have parvo, so if your puppy is exhibiting these symptoms do not wait to see a veterinarian.  Puppies can die within 24 hours of developing symptoms without treatment! 

There is a simple snap test that takes about 10 minutes to run in the clinic.  We will take a stool sample and have an answer very quickly.  This test, though very accurate, can occasionally have false negative results.  If your puppy is exhibiting symptoms of parvo and the test is negative, treating and retesting in 24 hours is warranted to make sure the diagnosis is not missed.   We will also run a complete blood count and biochemistry panel to check for bone marrow suppression, infection, and the degree of dehydration in your puppy.  This will help us with our treatment.

Unfortunately, parvo treatment is expensive.  Puppies are usually in the hospital for 5-7 days on intensive care.  The average hospital bill can be $1000-1200.   Treatment consists of:

• Aggressive intravenous fluids
• Anti-nausea medication
• Pain medication
• Broad spectrum antibiotics
• Tamiflu (this interferes with viral replication)
  
• Potentially plasma transfusions if necessary 
  

Repeated bloodwork is done to assess how the treatments are going.  The good news is, there is an 80% or higher survival rate for puppies treated in the hospital for parvo.  The survival rate drops dramatically if outpatient care only is given.  This consists of anti-virals, antibiotics, anti-nausea medication, and subcutaneous fluids given at home by the owner.  Unfortunately, we usually cannot control the level of dehydration with subcutaneous fluids alone. 

Hopefully your dogs are well vaccinated against parvovirus.  Puppies should get a series of 3-4 vaccinations and then yearly boosters after that.  If your dogs are older and well vaccinated, the risk should be minimal.  Dogs over 1 year of age also develop somewhat of a natural resistance to the virus, so most infections are in puppies under 1 year of age.  That being said, older, unvaccinated (and even some well vaccinated) dogs are still susceptible to parvovirus.  If you have a puppy that has come down with parvovirus, here are some recommendations to follow:

• Bleach kills parvovirus.  Bleach any hard surfaces, food bowls, toys, bedding and anything else the puppy has contacted.  A dilution of 1 part bleach to 30 parts water (or more concentrated) is needed to kill the virus. 
  
• Carpets cannot be bleached.  It takes a minimum of 30 days for the virus to die indoors.  Do not introduce any new puppies or unvaccinated dogs to your home for at least 60 days.
• Backyards are problematic.  The virus is very hardy in the environment and can live outdoors and remain infective for 5-7 months.  No new puppies or unvaccinated dogs can be exposed to the yard during this time.

Once your puppy recovers from parvo, it will not be susceptible to re-infection, but your puppy can continue to be infective to other dogs for 30-45 days after clinical signs resolve.  Keep your puppy away from other dogs for 2 months after being discharged from the hospital. 

In rare cases, puppies can get secondary problems related to parvovirus during the initial infection or within weeks to months after they have recovered.  These include:

• Parvoviral myocarditis - This is where the virus infects the heart muscle, and can lead to sudden death from heart failure, or these puppies can be prone to early heart failure later on in life.  There is no way to prevent this complication.  Most puppies that succumb to this are neonatal and/or their mothers were not properly vaccinated against parvo.
• Intestinal intussusception - Because there is so much damage to the intestinal tract during parvo, some puppies may get an intussusception after recovering from the disease.  This occurs when once loop of intestine passes inside another loop.  This acts like an intestinal obstruction.  If this occurs, surgery to remove the damaged piece of intestine is the only way to prevent it from happening again.