Canine Parvovirus

Canine parvovirus (CPV) is a highly contagious viral ailment primarily impacting dogs, with a heightened susceptibility among puppies and unvaccinated canine populations. Notably, the virus is recognized for its resilience and capacity to endure in the environment for extended durations. Leveraging years of expertise in animal disease research, BioVenic possesses a thorough comprehension of CPV and stands poised to deliver diagnostic and vaccine development services tailored to the needs of veterinary researchers.

Cause and Effect

CPV, categorized under the family Parvoviridae and the genus Protoparvovirus, is a compact, non-enveloped virus primarily attributed to the CPV-2. Upon entering a dog's body, the virus adheres to receptors on the surface of intestinal cells, initiating a cascade that destroys these cells and damages to the intestinal lining.

Fig. 1 Schematic diagram of CPV particle structure.¹

Fig. 2 Evolution diagram of CPV-2.²

Pathogenesis

CPV initially undergoes replication in pharyngeal lymphoid tissue and mesenteric lymph nodes. Once it enters the bloodstream, it primarily targets rapidly proliferating cell populations. In the initial two weeks following entry into the host, the active division of cardiomyocytes allows the virus to replicate, resulting in myocardial necrosis and myocarditis. In older pups, the virus invades actively dividing intestinal crypt epithelial cells. The loss of intestinal crypt cells leads to villi blunting, reducing absorptive and digestive capacity and causing diarrhea. Severely infected pups may experience extensive bleeding in their intestinal lumen. The intestinal mucosa and mesenteric lymph node tissue are associated with immunosuppression, predisposing dogs to secondary bacterial infections.

Epidemiology

While CPV is most frequently identified in dogs, it can also affect wolves, foxes, cats, and raccoons. Dogs of all ages and genders are susceptible to infection. The severity of the disease and its impact can vary, influenced by factors including the age and overall health of the affected dog. Puppies, particularly those before and after weaning, are particularly vulnerable. Additionally, specific breeds like Rottweilers, Dobermans, and American Staffordshire terriers may exhibit a higher susceptibility to severe CPV infection. Disease severity is further influenced by factors such as the viral load the dog was exposed to and its vaccination status.

The prevalence of the disease is notably high in locations where dogs congregate, such as pet wholesale markets, pet stores, and large-scale dog farms. Once the disease emerges in a group of dogs, preventing infection among other puppies is challenging unless they are maintained under strict isolation conditions.

Transmission

Dogs that are infected serve as the primary carriers of the disease. CPV is expelled through bodily fluids such as feces, urine, vomit, and saliva, thereby contaminating various elements like food, bedding, utensils, and the immediate environment. Furthermore, even dogs that have recovered may continue to shed infectious agents in their feces over an extended period, making asymptomatic infected dogs an additional source of contagion.

Signs and Symptoms

The clinical form and severity of the disease are largely determined by the age and immune status of the animal. Following a brief incubation period of 4 to 7 days, the animal will abruptly exhibit symptoms such as vomiting, anorexia, depression, and fever. Diarrhea sets in within 48 hours, often characterized by blood, and in severe cases, significant bleeding. The feces emit a foul odor.

Long-term cases of illness are uncommon, and animals with severe infections typically succumb within 3 days. Those that survive the infection develop enduring immunity.

While the myocarditis form of the disease is presently relatively rare, puppies infected before 8 weeks of age often manifest signs of acute heart failure.

Diagnosis of CPV

Fecal-oral transmission stands out as a significant mode of CPV transmission. Consequently, stool samples are commonly utilized for laboratory diagnosis of CPV. Our diagnostic solutions, designed or developed for customers, frequently incorporate immunodiagnostics and molecular diagnostics techniques, along with electron microscopy and virus isolation methods.

• ELISA: Detects CPV antigens in feces.
• PCR: Detection of CPV genetic material in feces.

Treatment

Dogs with CPV enteritis often die due to massive dehydration, blood loss, and shock. Therefore, during treatment, hemostasis and fluid replacement are key measures. At the same time, anti-virus and anti-bacterial infection is also indispensable.

Prevention and Control

Vaccination

Puppies should undergo a series of vaccinations initiated at an early age, with booster shots administered as advised by veterinarians. Consistent revaccination throughout a dog's life is crucial for sustaining immunity.

Hygiene Practices

Effective hygiene practices play a pivotal role in curbing the virus's spread. Swift removal and proper disposal of feces are imperative, accompanied by thorough disinfection of contaminated areas using effective disinfectants.

Limiting Contact

Additionally, it is essential to restrict unvaccinated dogs from areas with a heightened risk of contamination. Infected dogs should be kept separate from their counterparts to prevent further transmission within the infected group.

Canine health has been threatened by CPV for a long time. As a leader in biological research and veterinary medicine, BioVenic is committed to advancing our understanding of CPV and developing innovative solutions for its prevention, diagnosis, and treatment. If you want to cooperate with us, please feel free to contact us.

References

1. Arora, Richa, et al. "Canine parvovirus and its non-structural gene 1 as oncolytic agents: Mechanism of action and induction of anti-tumor immune response." Frontiers in Oncology 11 (2021): 648873.
2. Lin, Chao-Nan, et al. "Canine parvovirus type 2." Canine Medicine-Recent Topics and Advanced Research; Kaoud, HAE, Ed (2016): 1-17.