Systematic Veterinary Virology

SYMPTOMS

• Infected dogs are often asymptomatic and infection is triggered by stress, and clinical signs may be intensified by concurrent infection with opportunistic enteric pathogens. Prolonged contact with a dog shedding high levels of virus increases the likelihood of disease. There are two common clinical forms two common clinical forms of the disease—myocarditis and gastroenteritis. Myocarditis is observed in young pups, especially in the early neonatal period.
• Infection lead to myocardial necrosis with either acute cardiopulmonary failure (causing pulmonary edema, cyanosis, and collapse) or scarring of the myocardium and progressive cardiac insufficiency. Gastroenteritis is most common in pups 6-20 wk old. Gastrointesttinal form mostly seen in young male dogs of less than 1 year old.
• The severity of clinical signs varies. Dogs with the enteric form suffer from an acute onset of lethargy, anorexia, fever, vomiting, leukopenia and diarrhea. The feces are loose and may contain mucus or blood.
• Most dogs recover within a few days with appropriate supportive care; others can die within hours of the onset of clinical signs. Other clinical problems that have been associated with CPV include birth defects and infertility. Subclinical infections are common, especially in older dogs.