RELEASE IMMEDIATELY

     PARVO OUTBREAK

* Parvo virus is a viral disease that in puppies causes sudden vomiting,   diarrhea, and death. Parvoviral infection has become a disease almost   exclusively of puppies and adolescent dogs.

* We are having a particularly bad outbreak because of cool, weather.

* Parvo virus travels readily on hands, feet, shoes, clothing. It can be picked up   anywhere and spread because you can carry it on anything to new areas.

* The incubation period is 3 to 10 days.

* If you have a puppy, please vaccinate on time and get the complete series      of shots.

* Do not take your puppy out and about to reduce the possibility  of    exposure.   It is recommended that puppies be restricted from public outdoor areas until   their vaccination series is completed at age 16 weeks (4 months).

* If you do take your puppy somewhere please do not put them down on   floors, pavement etc., this will also reduce exposure.

    * If your adult dogs are overdue on their boosters this would be
a     good time to bring them up to date. Check with
       your veterinarian.

UNDERSTANDING PARVO VIRUS

     We all know what parvo isC a viral disease of the dog family, especially severe in puppies.  After a silent incubation period of 6 to 10 days,  the more serious cases are characterized by a sudden onset of vomiting and severe diarrhea, leading to collapse and death in short order from loss of body fluids, electrolytes, and septicemia (toxin producing bacteria invading the body through the damaged intestinal wall).  Not all cases are this severe and the mildest of cases may not even be recognized but the animal still sheds some virus.

     In coming issues we will discuss contamination and spreading of disease but today I would like to give you a better working knowledge of the disease and the agent that causes it.

     Viruses are life forms that are so elegantly simplified as parasites of bacteria and living cells of more complex organisms, that they almost defy the definition of aliveCuntil they start reproducing.  A typical parvo virus is nothing more than a little chunk of genetic material packaged and protected by a protein jacket.  Viruses are essentially inert (dormant) until they come into contact with their specific target cell.  Viruses are so small you could gather enough parvo virus to kill a dog on the head of a pin and still not be able to see it with a microscope.  The protein jacket of a virus has little projections on it that act as grappling hooks, or keys that fit into specific locks on the surface of it=s target cell allowing it to dock and transfer its genetic package inside.  Imagine a space shuttle docking with a large space station and unloading its human cargo.  At this point the cell is literally high jacked by the virus.  It uses the cell=s own machinery and energy  stores to replicate itself over and over until the cell is exhausted and so stuffed with the new viral particles it ruptures and dies releasing the new virus.

     In the case of parvo, which is NOT an airborne virus but is transmitted ORALLY to its most cooperative canine host (sniff-lick-slurp) from a contaminated surface or from the hands, feet, clothes and tools of parvo=s favorite helper species (that=s us).  The virus makes a quick pit stop in the tonsils ( and related tissues) to replicate once, to get it=s numbers up, then moves on through the body to it=s main target cellsC one set in the bone marrow which had been destined to be white blood cells and help the body in just such an impending emergency and the other set in the crypt cells lining the dogs intestine (gut).  This viral docking, replicating, cell death, viral release is happening in massive numbers of these surface cells lining the gut.  These dead cells are sloughing off in sheets into the lumen of the gut along with the newly released masses of viral particles.  The bacteria, which had been living in the gut  but separated by the cell lining, are now invading the body through the damaged gut wall adding their own toxic insult to the mix. 

The host dog once again cooperates with the virus, however involuntarily, by spewing millions of viral particles out both ends, along with much of it=s intestinal lining and most of it=s life fluids.

     In light infections the dog may get temporarily discomfited, in moderate infection the animal may be able to be assisted enough with oral fluids and medicines to survive but, from all this you can understand why the seriously afflicted animal requires intensive medical intervention with intravenous fluids and all antibiotics and medications given by injection for the 4-5 days it takes the intestine to reform it=s lining.  If the dog lives the recovery can happen this quickly because the virus only attacked the surface cell layer, and the cells that produce them are still in place and ready to regenerate.

     We now know parvo has a few strategies for survival:

     1.  Being small, invisible on surfaces, easily moved around on       people and objects.

     2.  Reproducing itself a million particles at a time.

     3.  Being dormant outside it=s host, able to hang around on surfaces for long periods of time waiting to get Alucky@

     4.  Having no water or cellular baggage that can be hurt by freezing (it=s impermeable to cold).

Parvo has other qualities that set it apartCthat is it=s resistance to common disinfectants.

     We are a large shelter with high numbers of stray dogs and susceptible puppies concentrated in one area ,we have large amounts of public passing through, we accept sick animals from the public, and have a small number of caretakers moving from animal to animal.  Between caretakers, public, and cleaning procedures there is probably some form of direct or indirect contact between every animal in the facility on any given day. 

     Because it is impossible to eliminate incoming viruses it is essential that every individual in the shelter makes a commitment to understand the nature of the disease, including the working knowledge of disinfectants and containment procedures and accepting personal responsibility to alter the workplace behavior that is contributing to contamination and the spread of disease. 

Shirley Magnuson DVM