The Treatment of Canine Parvovirus (Test and Cure)Parham Ziabakhsh Tabary*
Parham Ziabakhsh Tabary, Department of Specialized Veterinary Sciences, Islamic Azad University, Sciences and Research Branch, Turkey, Email: [email protected]
Received: 01-Oct-2022 Accepted Date: Oct 22, 2021 ; Published: 28-Oct-2021
IntroductionCanine parvovirus (also referred to as CPV, CPV2, or parvo) is a contagious virus mainly affecting dogs. CPV is highly contagious and is spread from dog to dog by direct or indirect contact with their faces. Vaccines can prevent this infection, but mortality can reach 91% in untreated cases. Treatment often involves veterinary hospitalization. Canine parvovirus may infect other mammals including foxes, wolves, cats, and skunks. Felines are susceptible to pan leukopenia, a different strain of parvovirus. Parvovirus CPV2 is a relatively new disease that appeared in the late 1970s. It was first recognized in 1978 and spread worldwide in one to two years. The viruses is very similar to feline pan leukopenia (also a parvovirus)
There are two types of canine parvovirus called canine minute virus (CPV1) and CPV2. CPV2 causes the most serious disease and affects domesticated dogs and wild canids. There are variants of CPV2 called CPV-2a and CPV-2b, identified in 1979 and 1984 respectively. Most of canine parvovirus infection are believed to be caused by these two strains, which have replaced the original strain and the present day virus is different from the one originally discovered, although they are indistinguishable by most routine tests.
Dogs that develop the disease show signs of the illness within three to seven days. The signs may include lethargy, vomiting, fever, and diarrhea (usually bloody). Generally, the first sign of CPV is lethargy. Secondary signs are loss of weight and appetite or diarrhea followed by vomiting. Diarrhea and vomiting result in dehydration that upsets the electrolyte balance and this may affect the dog critically. Secondary infections occur as a result of the weakened immune system. Because the normal intestinal lining is also compromised, blood and protein leak into the intestines, leading to anemia and loss of protein, and endotoxins escape into the bloodstream, causing end toxemia. 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. Younger animals have worse survival rates. Diagnosis is made through detection of CPV2 in the feces by either an ELISA or a hem agglutination test, or by electron microscopy. PCR has become available to diagnose CPV2, and can be used later in the disease when potentially fewer viruses is being shed in the feces that may not be detectable by ELISA.
Clinically, the intestinal form of the infection can sometimes be confused with coronavirus or other forms of enteritis. 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.
Survival rate depends on how quickly CPV is diagnosed, the age of the dog, and how aggressive the treatment is. There is no approved treatment, and the current standard of care is supportive care, involving extensive hospitalization, due to severe dehydration and potential damage to the intestines and bone marrow. A CPV test should be given as early as possible if CPV is suspected in order to begin early treatment and increase survival rate if the disease is found. In addition to fluids given to achieve adequate rehydration, each time the puppy vomits or has diarrhea in a significant quantity; an equal amount of fluid is administered intravenously. The fluid requirements of a patient are determined by the animal's body weight, weight changes over time, degree of dehydration at presentation, and surface area. A blood plasma transfusion from a donor dog that has already survived CPV is sometimes used to provide passive immunity to the sick dog. Some veterinarians keep these dogs on site, or have frozen serum available. There have been no controlled studies regarding this treatment. Additionally, fresh frozen plasma and human albumin transfusions can help replace the extreme protein losses seen in severe cases and help assure adequate tissue healing. However, this is controversial with the availability of safer colloids such as Heptastich, as it will also increase the colloid osmotic pressure without the ill effect of predisposing that canine patient to future transfusion reaction.