PARVOVIRUS INFECTION IN DOGS
Canine Parvovirus (CPV) is a highly contagious virus that commonly causes gastrointestinal disease in — young, unvaccinated dogs. Signs include – anorexia, lethargy, vomiting and diarrhea which is often hemorrhagic. Parvovirus comes from Latin word “Parvus” which means small, and probably due to this reason this virus is known as Parvovirus. Dogs of all age groups may be infected, but puppies of 3 months are highly susceptible than adults. This virus causes high morbidity (100%) and frequent mortality up to 10% in adult dogs and 91% in pups.
THE RESPIRATORY SYSTEM: DANCE OF THE INCOMING AND OUTGOING AIR
The respiratory system is important in the sense that it helps provide the body with the necessary elements of gases, such as oxygen, which help generate energy and power for the cells. The respiratory system is like a conducting system, a system that conducts the good gas, oxygen, into the body and helps expel the carbon dioxide gas out of the body. Carbon dioxide is an excretory product, and it is extremely important that this waste product is efficiently expelled out while the oxygen is being transported inside the body, which plays an important role in helping nourish the cells. This system encompasses the nostril, the conducting system – and the lungs.
Although its exact origin is unknown, it is believed to have arisen from FELINE PANLUEKOPENIA VIRUS CPV probably arose as a result of two or three genetic mutation in FPV that allowed it to expand its host range to infect dogs. It was first emerged in dogs in Europe around 1976. By 1978, the virus had spread unchecked, causing a worldwide epidemic of myocarditis (inflammation of heart muscles) and inflammation of intestines (gastroenteritis).
Outbreaks of CPV have been reported from many countries, including India. The prevalence study in India was first reported by Balu and Thangarajin in Chennai. The pattern of disease experienced in a population is largely influenced by the susceptibility of host, environmental conditions, such as housing, hygiene, population density and pathogenicity of the infectious agent.
Different Strains Of Canine Parvovirus
Three slightly different strains of canine parvovirus named CPV-2a, CPV-2b and CPV-2c are recognised. They cause the same disease and the vaccine gives protection against each one of them. CPV-2b is associated with most severe disease. A distinct type of Parvovirus (CPV-1) has also been found in pups with diarrhea in normal dogs. CPV-1 is now believed to be an important cause of disease. Young (6 weeks to 6-months old) unvaccinated or incompletely vaccinated dogs are most susceptible. Although severe clinical disease typically occurs in dogs younger than 6 months of age, adults with insufficient immunity may potentially be affected. However, CPV-2 is ubiquitous and can survive in the environment for more than a year, enabling exposure of susceptible dogs to infected faeces, vomitus or fomites. Breeds described at increased risk include:
- Doberman pinschers
- American Pit Bull Terriers
- English Springer Spaniels
- German Shepherds
- Labrador Retrievers
- Doberman, Rottweiler and German shepherd (GS) dogs have been reported to be more susceptible to CPVE than other breeds. Due to inherited immunodeficiency, the exceptional breeds, German Shepherds and Doberman, are extra prone than the different breeds. German Shepherds has the highest CPV infection rate (70%) followed by the Doberman (55%).
Assuming sufficient colostrum ingestion puppies born to a dam with CPV antibodies are protected from infection for first few weeks of their life, however susceptibility to infection increases as maternally acquired antibodies wanes.
The risk factors for the CPV diseases generally increases for the below-mentioned conditions:
- Breed predisposition.
- Possible simultaneous conditions, diseases or drug therapy that lead to an inability to develop a normal immune response (known as “immunosuppression”), such as heavy parasitism.
- Incomplete vaccination protocol, vaccine failure or regular interference of the doggy creating protecting antibodies due to the presence of maternal antibodies.
- Breeding kennels, pounds, shelters and areas with an excessive quantity of pups besides ample immune response or inadequately vaccinated puppies.
CPV is a small, non-enveloped, single-stranded DNA viruses that replicates in the nucleus of dividing cells in late S phase or early G2 phase of the cell cycle.
Once a dog or puppy is infected, there is an incubation period of 3–7 days before onset of the first symptoms. CPV wants the assist of swiftly dividing cells in order to correctly motive the disease, and the virus commonly starts off to evolve with the aid of attacking the tonsils or lymph nodes of the throat. Once inside the lymph nodes, the virus typically invades lymphocytes for one or two days creating many copies of itself, and then enter the bloodstream. Many of these CPV infected lymphocytes are ultimately killed, causing a reduction in the number of circulating lymphocytes (lymphopenia), thus decreasing the immunity system of the body.
Once in the blood stream, the virus again targets rapidly dividing cells, hitting hardest in the bone marrow and in the cells that lines the wall of small intestine. In infant or very younger dogs, CPV can additionally infect the coronary heart mainly causing irritation of coronary heart muscle, a terrible characteristic of arrhythmias.
The virus invades the crypts of Lieberkuhn of the small intestine where new epithelial cells are born and disables the body’s ability to replenish the intestinal surface, rendering it unable to adequately absorb nutrients, prevent fluid loss into the stool or prevent bacteria from moving from gut into the body. Severe diarrhea and nausea are the initial result, but eventually the intestinal surface can become so damaged that it begins to breakdown, and the bacteria that are normally confined to the gut penetrates the intestinal wall and enters the bloodstream.
This virus is sheded in the faeces of infected dogs within four to five days of exposure, throughout the period of illness and for upto 10 days after clinical recovery. Infection is received through direct oral or nasal contact with the virus containing faeces or circuitously through contact with contaminated virus on fomites.
Transmission & Infection Risk
Canine parvovirus is unfold with the aid of direct contact with a contaminated canine or sniffing or ingesting contaminated faeces. Infection can also spread through contact with items contaminated with the virus, such as shared bedding, bowls, soil, or even people’s hands or clothing, and in this way, the virus can be passed from one to another canines. Washing hands thoroughly with disinfectant soap and water can remove the virus. Specific disinfectants need to be used to eliminate parvovirus from the environment, inclusive of toys, garb and cages.
Can People Get Sick With It?
No, contamination with dogs parvovirus has now not been documented to have infected people. However, people can spread it to other dogs if they have the virus on their hands or clothing, and then touch other non-infected dogs or their environment (e.g. kennel, toys, grooming tools, etc.) can spread this disease among the uninfected canines. To conclude, the best prevention of this virus is only through maintaining good hygiene and vaccination. So, next time be very careful while handling the case of CPV contaminated dog and maintain a good hygienic routine.