Stages of Neospora caninum
- Oocysts: Unsporulated, noninfectious stage formed in the canine intestinal epithelium and passed with the feces
- Tachyzoites: Stage found in intermediate hosts and they occur intracellularly. rapidly dividing stages that actively invade tissues
- Bradyzoites: Slowly dividing stage in the intermediate host that encyst within their tissues
Transmission is in two ways
Horizontal:
- Pathogens are spread through non-hereditary means to other members of the same or different species.
- Ingestion of sporulated oocysts that may be present in soil and water sources contaminated with dog feces.
- Through infected tissues of intermediate hosts or with undercooked or raw meat, fetal membranes contaminated with sporulated oocysts or tissue cysts
Vertical:
- Pathogen transmitted to baby from mother during the period immediately before and after birth.
- Transplacental transmission with fetal infection during Terminal stages of gestation
- Transmammary transmission- postnatal transmission of tachyzoites via milk
Environmental resistance:
N. caninum oocysts are the only pathogen reported to date that can shed environmentally resistant oocysts. They can survive in the environment for months to years. Oocysts become infective (sporulate) in the environment within 1-3 days.
Morbidity:
Neosporosis has a worldwide distribution; depending on the country, the serologic prevalence in domestic dogs ranges from 0 – to 100%.
Dogs residing in the presence of cattle, Free-roaming dogs, sports, and hunting dogs are more commonly seropositive.
Diagnosis:
- Serologic assays include IFA of CSF or serum.
- Microscopically detecting tachyzoites in tissue aspirates
- Bradyzoites in biopsy samples of affected muscles.
- Serum biochemistry profile, and urinalysis
Mortality:
Neosporosis is a destructive disease with a high case fatality rate in puppies and leading to serious sequelae (long-term complications). The mortality rate decreases with age.
Prognosis:
The prognosis for puppies is poor.
In adult dogs, neurologic signs (such as central nervous system involvement), pneumonia inflammation of the liver and heart as well as skin inflammation with sores may occur. The prognosis deteriorates in dogs that are not treated promptly or with severe signs.