Canine parvovirus is a sometimes fatal gastrointestinal infection that mainly affects puppies.

             

                 

                

                     Canine parvovirus type 2 (CPV2, colloquially parvo) is a contagious virus mainly affecting dogs. The disease is highly contagious and is spread from dog to dog by direct or indirect contact with their feces. It can be especially severe in puppies that are not protected by maternal antibodies or vaccination. It has two distinct presentations, a cardiacand intestinal form. The common signs of the intestinal form are severe vomiting and dysentery. The cardiac form causes respiratory or cardiovascular failure in young puppies. Treatment often involves veterinary hospitalization. Vaccines can prevent this infection, but mortality can reach 91% in untreated cases. Canine parvovirus will not infect humans.

                 There are two forms of CPV2: intestinal and cardiac. Puppies are most susceptible, but more than 80 percent of adult dogs show no symptoms. Dogs become infected through oral contact with CPV2 in feces, infected soil, or fomites that carry the virus. Following ingestion, the virus replicates in the lymphoid tissue in the throat, and then spreads to the bloodstream. From there, the virus attacks rapidly dividing cells, notably those in the lymph nodes, intestinal crypts, and the bone marrow. There is depletion of lymphocytes in lymph nodes and necrosis and destruction of the intestinal crypts.   This type of infection can occur when a pregnant female dog is infected with CPV2. The adult may develop immunity with little or no clinical signs of disease. The virus may have already crossed the placenta to infect the fetus. This can lead to several abnormalities. In mild to moderate cases the pups can be born with neurological abnormalities such as cerebellar hypoplasia. 

Signs and symptoms              

 Dogs that develop the disease show symptoms of the illness within 3 to 10 days. The symptoms include lethargy, vomiting, fever, and diarrhea (usually bloody). Diarrhea and vomiting result in dehydration and secondary infections can set in. Due to dehydration, the dog's electrolyte balance can become critically affected. Because the normal intestinal lining is also compromised, blood and protein leak into the intestines leading to anemia and loss of protein, and endotoxins escaping into the bloodstream, causing endotoxemia. Dogs have a distinctive odor in the later stages of the infection. The white blood cell level falls, further weakening the dog. Any or all of these factors can lead to shock and death. The first sign of CPV is lethargy. Usually the second symptoms would be loss of appetite or diarrhea followed by vomiting.

Diagnosis 

            Diagnosis is made through detection of CPV2 in the feces by either an EIA or a hemagglutination test, or by electron microscopy. PCR has become available to diagnose CPV2, and can be used later in the disease when potentially less virus is being shed in the feces that may not be detectable by EIA. Clinically, the intestinal form of the infection can sometimes be confused with coronavirus or other forms ofenteritis. Parvovirus, however, is more serious and the presence of bloody diarrhea, a low white blood cell count, and necrosis of the intestinal lining also point more towards parvovirus, especially in an unvaccinated dog. The cardiac form is typically easier to diagnose because the symptoms are distinct.

PREVENTION:

                 Prevention is the only way to ensure that a puppy or dog remain healthy because the disease is extremely virulent and contagious. The virus is extremely hardy and has been found to survive in feces and other organic material such as soil for over a year. It survives extremely cold and hot temperatures. The only household disinfectant that kills the virus is bleach.