Canine parvovirus (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 cardiac and 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.
Parvovirus is contagious to dogs only—not to cats or people. Any age, breed, or sex of dog could be affected by parvovirus. However, infection with parvovirus does not automatically mean illness. Several factors such as age, environment, stress, parasites, and general health status of each individual dog infected could affect the severity of the disease. The degree of illness could range from very mild to unapparent to very severe, often resulting in death. The disease is usually more severe in young dogs (less than 6 months of age), old dogs, Rottweilers, and Dobermans. The younger and smaller the dog, the greater the chance that it will not recover.
Parvovirus is resistant to extremes of temperature (i.e., it survives freezing and extreme heat) and is unharmed by detergents, alcohol, and common disinfectants. Direct transmission occurs when an infected dog comes in contact with a healthy dog. The virus is found in heavy concentration in the infected dog’s stool. Because dogs will usually sniff where another dog has eliminated, this fecal-oral transmission is the most common method of transmission. The virus particles can be easily spread by hands, shoes, clothing, or other inanimate objects (fomites)—this is an indirect source of transmission.
As many as 30 billion parvovirus particles can be shed from the intestines of an infected dog in every ounce of stool. The highest concentration of virus in the stool is seen when the infected dog is showing signs of illness. A dog can, however, be a source of infection to other dogs without it having observable signs of illness (the disease may be incubating). Transmission can occur for at least 3 weeks after a dog becomes infected with the virus. Chronic “carriers” are not known to exist as in other viral diseases. Parvovirus in the environment can infect susceptible dogs for as long as 6 months once shed in the stool.
Clinical Signs and Symptoms :
The most common symptoms of this disease (the “intestinal form”) are vomiting and diarrhea. Another less common form, the “cardiac form”, occurs in very young pups (less than 8 weeks of age) and attacks the heart muscle, often resulting in sudden death.
Symptoms of Parvo in Dogs
Symptoms of Intestinal form (any age dog affected, but more severe in puppies):
- Loss of appetite
- Fever (usually above 103F)
- Vomiting with or without blood
- Diarrhea with or without blood (more serious if blood present)
- Low white blood cell count (due to immunosuppression)
Symptoms of Cardiac form (less than 8 weeks of age):
- Sudden death
- Crying, difficulty breathing, gasping for breath
- Extreme depression
- Unwillingness to nurse
- Irregular heartbeat
vomiting, fever, loss of appetite, depression, and bloody diarrhea with a very foul odor. Infected animals rapidly dehydrate and severe cases progress to shock and death.
Treatment of Parvo in Dogs
Treatment is aimed at maintaining the normal body composition and preventing secondary bacterial infection. Because this is a virus, there is NO CURE. Death from parvovirus results from dehydration, overwhelming secondary bacterial infection, blood loss from intestinal hemorrhage, or heart attack from invasion of the heart muscle by the virus. Early FLUID THERAPY is the most important factor in treating dogs with parvovirus infection. The body is normally about 80% water. Life is NOT possible when 12-15% of the normal body fluids are lost. Intravenous fluids both rehydrate the body and nourish the sick dog.
Additional treatment includes prevention of secondary bacterial infection and drugs to control vomiting and diarrhea. No food or water is given while the dog is vomiting. Repeated laboratory tests are often necessary to monitor your pet’s white blood cell count and state of hydration.
HOSPITALIZATION enables us to provide the best medicine and is the best way to achieve success. There is NO GUARANTEE, even with hospitalization, that your pet will survive. With most dogs, there is at least a 70% survival rate. Very small (young) puppies, Rottweilers, and Dobermans usually only have a 30-50% chance of survival. Length of treatment depends on the severity of disease. Most dogs have to stay hospitalized for at least 2-4 days, but may require treatment for as long as a week. Dogs that recover from parvo are often weak, making them even more susceptible to other diseases, such as distemper. Dogs that recover from parvo continue to spread the virus in the feces for a month or longer.
Early, vigorous treatment of illness caused by canine parvovirus infection can save lives.
Prevention and Control
Dog parvo prevention is really the same as rabies prevention; you just have to make sure your dog has all of their necessary vaccinations.
Vaccinations should start after the puppy is 6 to 8 weeks old. Up until that point, a puppy is typically protected against most sicknesses because its mother’s anti-bodies are still flowing through it’s blood. But now it has to build up its own system of protection.
The initial shot is followed by booster shots in the following weeks, followed by a yearly one after that to keep the protection up. Unless your dog is of a particularly susceptible breed, it’s probably safe to discontinue the booster shots after a few years.
As always, talk to your vet to get your dog on an appropriate vaccination schedule to minimize the risks of this deadly virus.
Control of parvovirus by sanitation measures alone is extremely difficult because the virus is such a resistant, hardy organism and because it is so easily spread. Contact with other dogs,and especially their stool, should be minimized. Clorox diluted one part to 30 parts water (4 oz Clorox in 1 gallon of water) has been effective in disinfecting inanimate objects such as clothing, floors, kennels, etc. However, it is impractical, if not impossible, to disinfect public streets, parks, etc. Isolation of infected dogs is another method of control, moderately effective. Both of these measures will help reduce the amount of contagious virus in the environment, but only a full series of vaccinations, with appropriate booster intervals, will help to control the source of infection, the contagious shedding dog.
2. Only have the puppy around adult dogs that YOU KNOW are current on vaccinations. There should be no contact with stray dogs or dogs that you are not sure of.3.Do not let the puppy be exposed to any other puppies. These pups could be incubating the disease (and therefore be contagious) without showing signs of illness.
4. Always wash your hands after handling any dog.5.
Dogs remain HIGHLY SUSCEPTIBLE to parvo until 2-4 weeks after the last injection of the immunization series of vaccine.
- Your dog’s stool contains blood, or the diarrhea returns.
- You cannot medicate your dog as instructed.
- Your dog vomits or is reluctant to eat.
- There is a change in your dog’s general health.
- Your dog does not drink water