Canine Parvovirus

Worried about the “New Parvovirus?”  Don’t be!  If your pet is adequately vaccinated for parvovirus, then they will be covered for the newer strain.  If your dog is not vaccinated for parvovirus, they can become infected with any strain of parvovirus, regardless of age.  So if your dog has not been vaccinated in the past year for parvovirus, see your veterinarian today!  Don’t delay!  It could mean the difference between the life and death for your four-legged friends.

Parvovirus is a highly contagious viral infection of dogs, and is a leading killer of young puppies that have no immunity to the virus.  Non-specific clinical signs of parvovirus infection may include lethargy and anorexia (no appetite).  Classical signs of parvovirus typically begin with vomiting first, followed by severe diarrhea, dehydration, abdominal pain and death.  The diarrhea may be mucoid or liquid, and is often bloody and  malodorous.  

Canine parvovirus, or CPV-2, first emerged in the late 1970’s as a canine pathogen.  The virus is believed to be the result of a spontaneous mutation from a virus that infected wild carnivores, perhaps foxes, and is related to the Feline Panleukopenia Virus (FPV).  Soon after this mutation CPV-2 emerged.   The virus mutated much like the human influenza virus, creating two variants.  The original CPV-2 was replaced with CPV-2b and CPV-2c.  The difference between the original virus and the newer CPV-2c strain is a seven-member amino acid sequence.  

Several breeds are suspected to have an increased susceptibility to parvovirus including pitt bulls, the Rottweilers and the Doberman Pinchers.  The relationship between breed and the frequency of parvovirus infection has also been speculated to be more socioeconomic in origin.  People in those parts of the country who require protection from an aggressive breed of dog may also be less likely to afford a complete series of vaccinations for newly acquired animals.  Parvovirus is suspected to be more established in poor, densely populated neighborhoods due to increased frequency of exposure to susceptible animals.  Canine parvovirus also infects the wild canine population including coyotes and the gray wolf. 

Diagnosis can be confirmed at most veterinary clinics through the IDEXX Snap Parvo Test™.   The snap test detects parvovirus antigen in fecal material.  Test results are available in as little as 8 minutes.  

Treatment consists primarily of supportive care.  Fluids and electrolytes must be replaced, for the primary cause of death is dehydration.  Drugs such as Cerenia® are given to control vomiting and are effective on many of the diverse mechanisms which initiate vomiting.  Antibiotics may be given to prevent secondary bacterial infection.  An antiviral drug Tamiflu® (oseltamivir phosphate) is  available from Roche pharmaceuticals and may prove effective against parvovirus especially when started early in the course of the disease. 

The primary means of viral transmission is via a fecal-oral route.  The incubation period (the time between infection and the onset of clinical signs) for this virus is 5 to 11 days.  Infected dogs will shed the virus for approximately two weeks.  High risk areas for exposure include pet stores, shelters, and dog parks.  A puppy can shed the virus for 3 days before exhibiting any clinical signs of infection.  The virus can remain infectious for up to 1 year in soil depending on the environmental conditions.  

Parvovirus has the highest incidence of occurrence in puppies under 3 months of age but any age dog may develop parvovirus.  The greatest mortality rate is also in puppies younger than 3 months of age.

A vaccine schedule for puppies to protect against parvovirus should begin at 6 weeks of age, and continue on a three-week interval until the puppies are greater than 16 weeks of age.  

A 1:40 dilution of bleach will disinfect contaminated areas.  

References:

“Managing Vomiting, Examining the Physiology, Common Causes and Control in Dogs, a Roundtable Discussion.”  Veterinary Medicine 2008.  Pp. 2-15.

Marie, Grant Editor.  The Pathology of Domestic Animals.  Vol. 2. 5th Edition. 2007. Pp. 180-181.

Rosenthal, Marie.  “Parvovirus 2C:  What’s the Story.”  Veterinary Forum.  April 2009. Pp. 18-22.

Yekaterina, Buriko and Cynthia Otto.  “Parvoviral Enteritis.”  NAVC Clinician’s Brief.  February 2007.  Pp.  33-35.