What is Parvovirus?
Canine parvovirus is a highly contagious viral disease that can produce a life-threatening illness. The virus attacks rapidly dividing cells in a dog’s body, most severely affecting the intestinal tract. Parvovirus also attacks the white blood cells, and when young animals are infected, the virus can damage the heart muscle and cause lifelong cardiac problem
What are the Symptoms of Parvovirus Iinfection?
There is a broad range in the severity of symptoms shown by dogs that are infected with parvovirus. Many adult dogs exposed to the virus show very few, if any, symptoms. The majority of cases of disease are seen in dogs less than 6 months of age with the most severe cases seen in puppies younger than 12 weeks of age. There are also significant differences in response to parvovirus infections and vaccines among different breeds of dogs, with Rottweilers, Doberman Pinschers, and Labrador Retrievers being more susceptible than other breeds.
The most common form of the disease is the intestinal form known as enteritis. Parvovirus enteritis is characterized by vomiting (often severe), diarrhea, dehydration, dark or bloody feces, and in severe cases, fever and lowered white blood cell counts. Acute parvovirus enteritis can be seen in dogs of any breed, sex, or age. The disease will progress very rapidly and death can occur as early as two days after the onset of the disease. The presence of gram negative bacteria, parasites, or other viruses can worsen the severity of the disease and slow recovery.
Types of Parvovirus?
The major symptoms associated with the intestinal form of a canine parvovirus infection include severe, bloody diarrhea, lethargy, anorexia, fever, vomiting, and severe weight loss. The intestinal form of CPV affects the body’s ability to absorb nutrients, and an affected animal will quickly become dehydrated and weak from lack of protein and fluid absorption. The wet tissue of the mouth and eyes may become noticeably red and the heart may beat too rapidly. When your veterinarian palpates (examine by touch) your dog’s abdominal area, your dog may respond with pain or discomfort. Dogs that have contracted CPV may also have a low body temperature (hypothermia), rather than a fever.
Causes of Parvovirus
The human parvovirus B19 causes parvovirus infection. This is different from the parvovirus seen in dogs and cats, so you can’t get the infection from a pet or vice versa.
Human parvovirus infection is most common among elementary school-age children during outbreaks in the winter and spring months, but anyone can become ill with it anytime of the year. It spreads from person to person, just like a cold, often through respiratory secretions and hand-to-hand contact.
Parvovirus infection can also spread through blood. A pregnant woman who is infected can pass the virus to her baby.
The illness is contagious in the week before the rash appears. Once the rash appears, the person with the illness is no longer considered contagious and doesn’t need to be isolated.
How is Parvovirus Transmitted?
Parvovirus is extremely contagious and can be transmitted by any person, animal or object that comes in contact with an infected dog’s feces. Highly resistant, the virus can live in the environment for months, and may survive on inanimate objects such as food bowls, shoes, clothes, carpet and floors. It is common for an unvaccinated dog to contract parvovirus from the streets, especially in urban areas where there are many dogs.
Is Parvo Always Deadly?
As a dog owner, one of the most frequently asked questions is whether parvo is always deadly. Many times when we hear of this disease it’s in relation to young puppies and, unfortunately, in these cases puppies generally cannot survive. When puppies are too young to be vaccinated against the parvo virus and they have not been protected by maternal antibodies as a result of vaccination of a breeding female, they lack the defenses to fight against this aggressive virus. In some cases; however, dogs can recover from parvo. When left untreated, the mortality rate of parvo virus infection is around 91%. When treated with more aggressive therapy, parvo mortality rates can drop to 20% to 5%, but not without lasting effects.
How is Parvovirus Disease Treated?
The treatment of parvovirus is fairly straightforward and directed at supportive therapy. Replacing fluids lost through vomiting and diarrhea is probably the single most important treatment.Intravenous administration of a balanced electrolyte solution is preferred, but in less severe cases, subcutaneous or oral fluids may be used. In severe cases, blood transfusions may be necessary. Antibiotic therapy is usually given to help control secondary bacterial infections. In those dogs who have severe symptoms, antiserum against endotoxins may be given. Corticosteroids may be given if the animal is in shock. In cases of severe vomiting, drugs to slow the vomiting may also be used. After the intestinal symptoms begin to subside, a broad spectrum de-worming agent is often used. Restricting the food during periods of vomiting is also necessary and parenternal nutrition (providing nutrients intravenously) may be necessary.
Undertaking the treatment of affected dogs and puppies without professional veterinary care is very difficult. Even with the best available care, the mortality of severely infected animals is high. Without the correct amount of properly balanced intravenous fluids, the chance of recovery in a severely stricken animal is very small.
All parvoviruses are extremely stable and are resistant to adverse environmental influences such as low pH and high heat. Exposure to ultraviolet light and sodium hypochlorite (a 1:32 dilution of household bleach – ½ cup bleach to 1 gallon of water) can inactivate parvovirus. The bleach solution can be impaired by organic matter and needs to have adequate exposure time and proper concentrations to work effectively.