Canine herpesvirus (CHV) often causes miscarriages and neonatal mortality in puppies younger than 3 weeks of age.

CHV has the ability to persist in the nerve ganglia. Fortunately, it is a virus sensitive to common disinfectants based on quaternary ammonium salts, phenolic derivatives or formol and is also inactivated by acid pH and heat.

Transmission occurs through the oral-nasal, vertical or venereal way. Usually, puppies become infected by the respiratory or digestive way, but also by the transplacental means during the passage through the birth canal. In adult dogs, the infection occurs via the oral-nasal route or during mating. The sources of elimination of canine herpesvirus are:

• nasal secretions (even up to 15 days after infection)
• vaginal secretions (in males up to 20 days after infection, in females up to 16 days)
• fetuses and fetal ovaries during an abortion
• secretions of infected puppies (i.e. tears, saliva, urine and feces)

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The virus is spread almost everywhere, but obviously in kennels there are high rates of infection, even in the absence of symptoms.