How are parvoviruses transmitted to dogs?
Parvoviruses, which belong to the family of CPV viruses, first appeared among dogs in Europe in 1976. The virus spread unchecked in the following years, causing a global epidemic with symptoms of myocarditis and gastroenteritis in dogs.
Given the clear link between the structure of parvoviruses and feline panleukopenia viruses, a hypothesis was put forward that parvoviruses arose as a result of two or three mutations in the viral DNA, which expanded the range of virus hosts to include dogs and other wild animals.
Symptoms of parvovirus infection in dogs
These viruses cause a highly contagious viral disease that affects 6-20 week old puppies and older dogs, especially those that are not vaccinated against this virus. Affected dogs present with severe gastrointestinal symptoms, beginning with lethargy and loss of appetite, ending with widespread sepsis and death. As for young puppies, the virus may skip the early stages to cause myocarditis in the puppies directly. Dogs infected with parvoviruses may exhibit all of the following:
- Fatigue and lethargy: the dog loses the degree of energy and activity it previously had.
- Anorexia.
- Abdominal pain and flatulence.
- Body temperature disorder: You may notice an abnormal increase or decrease in it.
- Vomiting and foul-smelling diarrhea: which may develop into vomiting and bloody diarrhea in the advanced stages.
- Tachycardia due to myocardial inflammation.
- Dehydration: This leads to an imbalance in electrolytes, damage to the intestines, and disturbances in the dog’s immune system.
- Secondary bacterial infection due to weak immune system and septicemia.
- Death: It often occurs within 48 to 72 hours after the appearance of clinical signs, which requires contacting the veterinarian immediately after the appearance of symptoms and referral to the veterinary clinic to provide the correct treatment.
How are parvoviruses transmitted to dogs?
Parvoviruses are present in almost any environment, but they do not infect all dogs, even those in contact with the virus. Several factors play a role in the occurrence of infection, including the immune status of the dog and the number of viruses it is exposed to.
The virus is spread through direct contact between infected and healthy dogs, and it is also transmitted through contact with feces contaminated with the virus or contact with a component of the contaminated surrounding environment, such as the dog’s food and water bowls. The virus is not transmitted from dogs to humans, but humans may play the role of a carrier of the virus and transmit it to dogs through their hands, or contaminated clothes and shoes.
The virus targets the epithelium of the small intestine, destroying the intestinal lining responsible for the absorption of nutrients and fluids and the maintenance of electrolyte fluid homeostasis in the body. This lining forms an impenetrable barrier against bacteria, viruses, and foreign bodies, which explains the symptoms of infected dogs.
How is dog parvovirus diagnosed?
As a first step, the dog’s symptoms are examined and compared with those mentioned above. Next, the vet performs the ELISA test, which is the most common and most convenient way to detect parvoviruses.
In this test, a sample of the dog’s blood or saliva is taken, and a chemical is added to the sample. If the color of the sample changes after adding the chemical, the result is positive and the dog is infected. If it does not change, the possibility of infection is small. Although the ELISA test is fairly accurate, the doctor may encounter some false positive or false negative results, so further testing may be necessary to confirm the diagnosis.
In the next step, veterinarians rely on conducting a polymerase chain reaction (PCR) test on stool samples, as this test detects the presence of viral DNA in the stool of an infected dog. This test is very accurate but requires a stool sample to be sent to a specialized laboratory, which takes longer than the ELISA test, which takes up to 15 minutes.
What do you do if your dog has parvovirus?
Treatment options vary depending on how bad the dog’s general condition is. A stay at the veterinary clinic is often necessary so that the dog can receive intravenous fluids and nutrients to treat dehydration. Anti-nausea and anti-vomiting drugs can be started, and cases of vomiting and bloody diarrhea may require blood transfusions to replace what has been lost. Treatment with antibiotics is essential due to the fact that the dog has a weakened immune system that makes it unable to fight even the simplest infections.
Many dogs respond well to medical treatment if it is started early. The good news is that dogs who recover from parvovirus infection retain a lifelong protective immunity against the strain that infected them.
How to protect your dog from infection with parvovirus?
This infectious disease has become less threatening to dogs after the development of a number of effective vaccines against strains of this virus, but this also does not mean that parvoviruses do not pose any threat to the health of dogs, and therefore vaccination of dogs against parvovirus should be considered a must and not an option. Veterinarians now administer CPV as part of a combination vaccine that includes tuberculosis, adenovirus, influenza, and parainfluenza. These injections are given every 3 to 4 weeks, starting at 6 weeks, until he is at least 16 weeks old. It is also recommended that the booster vaccine be given one year after the last dose, and every three years thereafter.