Related Resources

Parvovirus Suspected When Bloody Diarrhea Occurs

Oct 23, 2012

Canine parvoviral enteritis, caused by the canine parvovirus, is a highly contagious disease in dogs that affects their digestive system. Before the late 1970's, parvoviral enteritis did not even exist and most of what we now know of this disease has been discovered since then. It is now known that the disease is transmitted via the oral/fecal route. Huge numbers of virus are shed in the stools of infected dogs for up to two weeks after infection. Since the virus is extremely hardy, it can survive and remain infectious for months in the environment and is extremely difficult to kill with disinfectants.

Once an unprotected dog is exposed to the virus, it only takes about 5 days to show signs of the disease. These signs can include loss of appetite, lethargy, fever, vomiting, and profuse and usually bloody diarrhea. Death occurs in severe cases, usually as a result of dehydration, overwhelming infection, or shock. This is especially true in young unprotected dogs (especially puppies between weaning and six months of age), although dogs of any age can become infected. Certain breeds such as Rottweiler and Doberman Pinschers are at higher risk.

Parvoviral infections can occur inside the uterus during pregnancy or shortly after birth, causing acute inflammation of the puppies' heart muscles (called myocarditis). While this was quite common in the early days of the disease, this rarely occurs now since most dams are protected against the virus (usually via vaccination) and pass on their immunity to their puppies.

Parvoviral enteritis is often suspected when bloody diarrhea occurs in a dog. A simple test is available that can be performed quickly and inexpensively at a veterinary hospital. Fortunately, most dogs recover with early treatment. In fact, if an animal can survive the first three to four days of illness, a full recovery can be anticipated barring unforeseen complications.

Since the virus is so tough and can survive in the environment for such a long time, it is almost impossible to prevent exposure. Vaccination is the only truly effective way of preventing and controlling this disease. Your veterinarian can advise you on which vaccination schedule is best suited for your dog.