Introduction

• Cause: canine adenovirus type 1.
• Signs: hepatitis, kennel cough Acute infectious tracheobronchitis , mortality in newly-weaned puppies and young dogs.
• Diagnosis: history, signs, virus isolation.
• Treatment: supportive care, symptomatic management.
• Prognosis: good if mild, poor if severe.

Pathogenesis

Etiology

• Adenovirus serologically related to canine adenovirus type 2 Canine adenovirus type 2.
• Cross-protective immunity between canine adenoviruses 1 and 2.
• 75 nm DNA virus, without lipoprotein envelope.
• Moderately resistant: survives in environment from days to months.
• Infectivity destroyed at 56°C → disinfect kennels with steam for >5 min.
• Resistant to many disinfectants; susceptible to quaternary ammonium compounds.
• Range of virulence.

Predisposing factors

• Young dogs.

Specific

• Seronegative; unvaccinated.

Pathophysiology

• Infection by oronasal route → primary replication in tonsils and regional lymph nodes.
• Release of virus → viremia; free virions in plasma within 8-72 hours.
• Target organs: liver and kidneys → secondary replication in hepatic parenchymal cells and reticuloendothelial system.
• Direct effects of viral replication → cell lysis/necrosis → clinical signs.
• Focal areas of hepatocellular destruction may coalesce → hepatic necrosis → jaundice.
• Infection of endothelial cells → effusions and hemorrhagic diathesis.
• Immune-mediated keratitis → corneal edema.
• Immune-mediated glomerulonephritis.
• Either death or recovery with urinary excretion of virus for up to 1 year.
• Recovered dogs have life-long immunity.

Timecourse

• Incubation period 4-7 days → viremia.
• Fever for 24 hours.
• Mild cases recover in 1-2 days.
• Moderate hepatitis cases recover in 3-5 days.
• Virus may be shed in urine for at least 6-9 months after recovery.

Epidemiology

• Acutely infected dogs shed virus in all body secretions/fluids.
• CAV-1 may localize in renal tubules → virus shed in urine for at least 6-9 months post-recovery.
• Infection by oronasal route from contaminated environment; rarely by aerosol.

Diagnosis

Treatment

Prevention

Outcomes